Technological pipelines include pipelines within oil depots and oil product warehouses, through which oil and oil products, oils, reagents, steam, water, fuel are transported, ensuring the conduct of the technological process and operation of equipment, as well as oil product pipelines, through which oil products are sold to nearby organizations located on the balance of tank farms (between the tank farm and the refinery, loading berths, separate railway and auto racks, etc.).

The arrangement and operation of process pipelines as part of tank farms and oil product warehouses is carried out in accordance with the requirements for the arrangement and safe operation of process pipelines, the arrangement and safe operation of steam and hot water pipelines.

Organizations that operate technological pipelines (tank depots, oil product warehouses) are responsible for the correct and safe operation of pipelines, control over their operation, timely and high-quality inspection and repair.

The design organization must determine the estimated service life, categories and groups of pipelines.

For the transportation of oil and oil products, only steel technological pipelines should be used. The use of pipes made of glass and other fragile materials, as well as from combustible and slow-burning materials (fluoroplastic, polyethylene, vinyl plastic, etc.) is not allowed.

Pipelines for fuel depots of aviation enterprises must be made of low-carbon steel and have an internal anti-corrosion coating applied at the factory. These pipelines must also have an external anti-corrosion coating, and, if laid underground, cathodic protection against stray currents.

Pipelines for PVKZh should be made only of stainless steel.

It is not allowed to use materials made of copper and cadmium alloys and galvanized steel in the structures of aviation fuel supply pipelines.

Depending on the corrosiveness of the pumped oil product and the estimated service life, the thickness of the pipeline wall should be determined, adjusted for corrosive wear.

Technological pipelines with oil and oil products, laid on the territory of oil depots, must be elevated on fireproof structures, overpasses, racks and supports.

Above-ground technological pipelines laid on separate supports, overpasses should be placed at a distance of at least 3 m from the walls of buildings with openings and at least 0.5 m from the walls of buildings without openings.

Technological pipelines must be made of electric-welded and seamless pipes, including those with anti-corrosion coating. The choice of pipe materials and manufacturing method must be taken depending on the properties of the pumped medium and operating parameters.

Connections between pipelines must be welded. When pumping solidifying oil products through pipelines, as well as in places where fittings and process equipment are installed, it is allowed to use flange connections with gaskets made of non-combustible materials.

On process pipelines of large diameter and long length, with the possibility of increasing pressure when heated from various energy sources (solar radiation, etc.), safety valves should be installed, discharges from which should be directed to closed systems (drainage or emergency tanks).

The need to install safety valves, their diameter and throughput are determined by the design organization.

There should be no dead ends, stagnant zones on technological pipelines.

At the lowest points of the pipelines, drainage devices with shut-off valves should be made.

The laying of pipelines for oil and oil products should be carried out with a slope so that they can be emptied during shutdowns, while the slopes for pipelines should be taken at least:

For light oil products - 0.2%;

For high-viscosity and hardening oil products - depending on the specific properties and features, length and laying conditions - 2%.

The supply of inert gas or steam for purging pipelines must be carried out at the beginning and end points of the pipeline. To do this, fittings with fittings and a plug must be provided.

Pipelines for pumping viscous products must be externally heated. Steam, industrial heating water and electric heating can be used as heat carriers. In the case of using electric heating with the help of tape heaters, the latter must be made in an explosion-proof design.

At the inputs of technological pipelines of oil and oil products to facilities (tank farms, pumping stations, railway and auto racks, berthing facilities), shut-off valves should be installed. Stop valve actuators should be controlled remotely from the operator's room and manually at the installation site.

Valve assemblies should be located outside the dike (enclosing wall) of groups or separate tanks, except for valves installed in accordance with clause 2.6.41.

On piping pipelines, the installation and location of shut-off valves should ensure the possibility of pumping oil from tank to tank in case of an emergency.

In the technological schemes of fuel oil facilities, steel seamless and electric-welded longitudinal pipes made of calm carbon and low-alloy steels should be used.

It is allowed to use imported pipes supplied complete with heat power units and production lines that have a certificate of conformity and permission for their use, issued in the prescribed manner.

To compensate for temperature deformations of pipelines in fuel oil facilities, self-compensation should be used due to turns and bends in the route or provision should be made for the installation of special compensating devices (U-shaped compensators).

The use of stuffing box, lens and corrugated compensators in fuel oil systems is not allowed.

On all fuel oil pipelines, steam pipelines and condensate pipelines of fuel oil facilities of thermal power plants, only steel fittings should be used. It is not allowed to use fittings made of malleable and gray cast iron and non-ferrous metals.

Shut-off valves installed on product pipelines must be made in accordance with the established requirements for the tightness class of pipeline shut-off valves.

Shut-off valves installed on pipelines with a nominal diameter of more than 400 mm must have a mechanical drive (electric, pneumatic and hydraulic methods of action).

Reinforcement weighing more than 500 kg should be placed on horizontal sections, while providing for vertical supports.

The design of seals, gland packings, gasket materials and installation of flange connections must provide the necessary degree of tightness during the overhaul period of the technological system.

Overhaul of explosion-proof valve actuators must be carried out in specialized organizations.

Laying of prefabricated collectors within the embankment of a group of tanks with a single capacity of more than 1000 m 3 is not allowed. This restriction does not apply to cases where it is possible to extinguish each tank with foam lifters installed on mobile fire fighting equipment for tanks with a single capacity of 3000 m 3 or less.

Ministry of Education and Science of the Samara Region

State budget educational institution

secondary vocational education

"Provincial College of Syzran"

Technical Profile

Toolkit

PROCESS PIPING

PM 01 Operation of the technological

equipment.

PM 05 Performing work by profession

Process plant operator

Syzran.

2015

Methodological guide on the topics of PM 01 "Operation of technological equipment,

PM 05 Performing work by profession Operator of technological installationsMDK 05.02. Repair of technological equipment.

(name of the methodological development)

Brief description of the Methodological guide

This methodological manual presents types of technological pipelines, operating rules, maintenance requirements, preparing them for repair and testing. Designed for students of SPO "GK of Syzran" in the specialty 240134.51 Oil and gas processing during training in the professional module PM 01. Operation of process equipment and PM 05 performance of work by profession Process plant operator.

The methodological manual will allow students to form knowledge and practical skills in the operation of equipment of oil refineries.

Compiled by: Pirogova Galina Nikolaevna- Specialist teacher disciplines.

APPROVED AT THE PCC MEETING

Oil and gas processing. Ecology

(commission name)

Chairman _____________________ V.V. Mokeeva

FULL NAME

Minutes No. __________ dated "____" __________ 2015

Technical profile methodologist _______________ L.N. Barabanova

FULL NAME.

"APPROVE"

Deputy Director for UPR

Head of technical profile __________________ V.V. Kolosov

Process pipelines

1. Learning goal

The purpose of studying the topic "Technological pipelines" is to teach students the classification, types of technological pipelines, operating rules, maintenance requirements, preparing them for repair and testing.

1.1. Concept, basic terms

Definition of technological pipelines, their classification. Location of pipelines. Elements of pipelines. Separation of pipeline fittings into: shut-off, control, safety. Types of attachment of fittings to pipelines. Structural elements of reinforcement. Operation and repair of technological pipelines.

Pipeline- a structure of pipes, pipeline parts, fittings, tightly interconnected, intended for the transportation of gaseous and liquid products.

technological called pipelines of industrial enterprises through which raw materials, semi-finished products, finished products, steam, water, fuel, reagents and other materials are transported, ensuring the implementation of the technological process and the operation of equipment, spent reagents, gases, various intermediate products obtained or used in the technological process, waste production.

Flanged connection- a fixed detachable connection of the pipeline, the tightness of which is ensured by compressing the sealing surfaces directly with each other or through gaskets located between them made of a softer material, compressed by fasteners.

Welded connection- a fixed connection of the pipeline, the tightness of which is ensured by welding.

Withdrawal- shaped part of the pipeline, providing a change in the direction of the flow of the transported substance.

Tee- shaped part of the pipeline for merging or dividing the flows of the transported substance at an angle of 90 0 С.

Union- a part designed to connect fittings, instrumentation, etc. to the pipeline.

Transition- shaped part of the pipeline, designed to expand or narrow the flow of the transported substance.

pipeline section- a part of a technological pipeline made of one material, through which a substance is transported at a constant pressure and temperature.

Pipeline accessories- devices installed on pipelines and providing control of the flow of working media by changing the flow area.

Conditional pass Du- nominal inner diameter of the pipeline, providing the required throughput.

Nominal pressure Ru- the lowest overpressure at a substance or ambient temperature of 20 0 C, at which long-term operation of fittings and pipeline parts with specified dimensions, justified by strength calculation, is permissible, with selected materials and their strength characteristics corresponding to this temperature.

Working pressure PP- the highest safe overpressure at which the specified mode of operation of fittings and pipeline parts is ensured.

Test pressure Ppr- excess pressure at which a hydraulic test of fittings and pipeline parts for strength and density with water at a temperature of not less than +5 0 С and not more than +40 0 С should be carried out.

2. The content of the educational element

To teach students the theory and practical performance of work on the operation, revision, repair of technological pipelines and pipeline fittings.

2.1. General concepts

Pipeline- a device designed for transportation of gaseous, liquid and bulk substances.

Depending on the transported medium, the names water pipeline, steam pipeline, air pipeline, oil pipeline, gas pipeline, oil pipeline, product pipeline, etc. are used.

The design of the pipeline must be reliable, ensure safety during operation and provide for the possibility of its complete emptying, cleaning, flushing, purging, external and internal inspection and repair, removal of air from it during a hydraulic test and water after it.

The main characteristic of any pipeline is the diameter that determines its flow area, which is necessary for transporting a given amount of a substance at operating operating parameters (pressure, temperature, speed).

All technological pipelines with pressure up to 100 kgf/cm 2 inclusive, depending on the hazard class of the transported substance (explosion and fire hazard and harmfulness), are divided into groups (A, B, C) and depending on the operating parameters of the medium (pressure and temperature) into five categories (I ,II ,III .IV ,V ).

Technological pipelines consist of tightly connected straight sections, pipeline parts (bends, transitions, tees, flanges), gaskets and seals, supports and hangers, fasteners (bolts, studs, nuts, washers), shut-off and control valves, control and measuring instruments, automation equipment, as well as thermal and anti-corrosion insulation.

Depending on the placement at the industrial facility, technological pipelines are divided into intra-shop, connecting units, machines and apparatuses of technological installations of the shop, and inter-shop, connecting technological installations of different shops. Intrashop pipelines are called piping if they are installed directly within individual apparatuses, pumps, compressors, tanks, etc. and connect them.

Intrashop pipelines have a complex configuration, a large number of parts, fittings and welded joints. For every 100 m of the length of such pipelines, there are up to 80-120 welded joints. The mass of parts, including fittings, in such pipelines reaches 37% of the total mass of the pipeline.

Inter-shop pipelines, on the contrary, are characterized by fairly straight sections (up to several hundred meters long), a relatively small number of parts, fittings and welds. The total mass of parts in intershop pipelines (including fittings) is 5%, and U-shaped compensators are about 7%

Technological pipelines are considered cold if they operate in an environment with an operating temperature t p  50 0 C, and hot if the temperature of the working medium > 50 0 C.

Depending on the conditional pressure of the medium, pipelines are divided into vacuum pipelines operating at an absolute pressure of the medium below 0.1 MPa (abs) or from 0 to 1.5 MPa (g), medium pressure, operating at a medium pressure from 1.5 to 10 MPa ( hut). Non-pressure pipelines are pipelines that operate without excessive pressure (“gravity flow”).

Connections in pipelines for the transport of liquefied gases should be made mainly by welding. In places of installation of fittings, in order to attach it to the pipeline, flange connections can be used. They can also be used in pipelines that require periodic disassembly in order to clean or replace individual sections. Welding is the most practical and reliable method of joining steel pipelines and fittings to pipelines. It is widely used in pipeline systems for various purposes, but in many cases flange connections are also used, which have their own advantages and disadvantages, as well as detachable connections. Threaded connections are often used in pipelines with small nominal diameters.

The location of pipelines should provide:

safety and reliability of operation within the standard period;

the possibility of direct observation of the technical condition;

the ability to perform all types of work on control, heat treatment of welds and testing;

insulation and protection of pipelines from corrosion, secondary manifestations of lightning and static electricity;

preventing the formation of ice and other plugs in the pipeline;

elimination of sagging and the formation of stagnant zones.

According to the method of laying pipes, pipelines or their sections are divided into the following:

underground- pipes are laid in a trench underground;

ground- pipes are laid on the ground;

elevated- pipes are laid above the ground on racks, supports or using the pipe itself as a supporting structure;

underwater- constructed at water crossings

obstacles (rivers, lakes, etc.), as well as during the development

ke offshore fields.

Questions for reflection:

What pressure is called working?

What are the requirements for pipeline design?

How are technological pipelines divided depending on their placement at an industrial facility?

Which process pipelines are considered cold?

What technological pipelines are intrashop?

Which pipes are used for transporting flammable and explosive media?

Where is it allowed to use flange connections in gas pipelines?

2.2. Pipeline accessories

Pipe fittings installed on pipelines or equipment are designed to disconnect, distribute, regulate, mix or discharge transported products.

According to the nature of the functions performed, the valves are divided into classes: control, safety, shut-off and miscellaneous.

Shut-off valves are designed to shut off the flow of the transported product (taps, valves, gate valves and rotary valves).

Regulatory– to control product parameters by changing its flow (control valves and valves, direct-acting regulators, mixing valves).

Safety- to protect installations, apparatuses, tanks and pipelines from unacceptable pressure increase (safety, bypass and check valves, as well as bursting discs).

According to the principle of operation, the armature can be autonomous (or direct action) and controlled.

Autonomous valves are called, the operating cycle of which is performed by the working medium without any extraneous energy sources (direct-acting pressure regulators, steam traps, gas vents).

A valve is called controlled, the operating cycle of which is carried out according to the corresponding commands at the moments determined by the operating conditions or devices.

According to the method of control, controlled valves are divided into valves with a manual drive (local control), valves with a drive (engine), and valves with remote control (at a distance).

Manually operated valves are controlled by the rotation of a handwheel or handle mounted on a spindle or running nut directly or through a gearbox.

The drive armature is equipped with a drive installed directly on it. The drive can be electric, electromagnetic, with a membrane or with an electric actuator, pneumatic, bellows pneumatic, hydraulic and pneumohydraulic. The fittings under remote control have control from the drive.

Depending on the design of the connecting pipes, the fittings are divided into flanged, coupling, pin and welded. Coupling and pin iron fittings are recommended only for pipelines with a nominal diameter of not more than 50 mm, transporting non-combustible neutral media. Coupling and pin steel fittings can be used on pipelines for all media with a nominal diameter of not more than 40 mm.

Flanged and welded fittings are allowed for use for all categories of pipelines.

The applied pipeline fittings must comply with the requirements of GOST 12.2.063 “Industrial pipeline fittings. General safety requirements”. The main types of connection of pipeline fittings to the pipeline are shown in Figure 1.

Pipeline fittings are delivered from manufacturing plants complete with mating flanges, gaskets and fasteners.

The choice of the type of sealing surface of the flanges for connecting pipelines depends on the transported medium and pressure.

For pipelines transporting substances of groups A and B of technological facilities of explosion category I, it is not allowed to use flange connections with a smooth sealing surface, except for the cases of using spiral wound gaskets.

a
- flanged (cast flanges with a connecting ledge and a flat gasket);

b - flanged (steel welded flanges end-to-end with a protrusion-cavity seal with a flat gasket);

c - flanged (cast flanges with a thorn-groove seal

with flat gasket);

g - flanged (steel flat welded flanges and flat gasket);

d - flanged (cast flanges with a lens gasket);

e - flanged (cast steel flanges with an oval gasket);

g - coupling;

h - tsapkovoe.

According to the method of shutting off the flow of the medium, the valves are divided into the following - a gate valve in the form of a disk, plate or wedge (it moves back and forth in its plane, perpendicular to the axis of the medium flow (Fig. 2).

locking or regulating body;

frame;

housing sealing surfaces.

Gate valves are divided into wedge and parallel gate valves. The wedge gate valve (Fig. 2) has a wedge gate valve in which the sealing surfaces are located at an angle to each other. They can be with a solid wedge (hard or elastic) and double-disk. Parallel gate valve can be sliding (single-disk or sheet) and double-disk with wedge thrust.

Questions for reflection:

What classes are pipe fittings divided into by the nature of their functions?

Purpose of safety fittings.

How controlled valves are divided by methods

management?

Name the ways to block the flow of the medium.

2.3. Structural elements of reinforcement

Various reinforcement designs contain parts and assemblies that have a common purpose and the same names (Fig. 8). These elements include the following:

to
corpus- a part that replaces a pipe segment with a length equal to the distance between the ends of the attached flanges or branch pipes for welding to the pipeline. The housing together with the cover forms a cavity hermetically isolated from the external environment, inside which the shutter moves;

1 - body; 2 - shutter; 3 - spindle; 4 - sealing gasket; 5 - pressure sleeve; 6 - flywheel; 7 - stuffing box; 8 - ring gasket; 9 - top cover; 10 - running nut; 11 - saddle.

gate- movable part of the working body - a part or a structurally integrated group of parts designed to hermetically separate two sections of the pipeline by blocking the through hole in the flow part of the body;

For hermetically shutting off the flow, a seat is provided in the body, equipped with a sealing ring. It can be formed by body metal, cladding of stainless steel, brass, or the installation of an O-ring made of stainless steel, brass, nickel alloy, plastic by pressing, threading, caulking and other fastening methods. The shutter in the valves is a valve plate (for small sizes it is called a spool), in gate valves - a wedge or a disk, or two disks at the same time, in taps - a plug in the form of a cone, cylinder or ball.

lid- a part used to hermetically cover the hole in the body through which the shutter is installed. In controlled fittings, the cover has a hole for the spindle;

spindle- a part, which is a rod, usually having a trapezoidal thread, with which the shutter is controlled. A spindle without a thread is called a stem.

The running nut also has a trapezoidal thread and forms a threaded pair with the spindle to move the shutter and set it to the required extreme or intermediate position (self-braking thread).

stuffing box- a device designed to seal the movable interface of the cover with the spindle;

flywheel- a part (usually a casting) that looks like a rim with a hub connected to the rim by spokes. Serves in manual control of the valve to transfer the torque generated by the hands to the spindle or valve stem nut. The small flywheel is made in the form of a solid disk.

2.4. Supervision of pipelines during operation.

2.4.1. Reliable trouble-free operation of the pipeline and the safety of its operation must be ensured by constant monitoring of the condition of the pipeline and its parts, timely repairs to the extent determined during inspection and revision, and renewal of all elements of the pipeline as wear and structural changes in the metal.

Fig.4.

2.4.2. By order of the enterprise in each workshop (at each installation), a person responsible for the safe operation of pipelines from among the engineering and technical workers serving these pipelines must be appointed.

2.4.3. Technological pipelines, depending on the properties of the transported medium, are divided into three main groups A, B, C, and depending on the operating parameters of the medium (pressure and temperature) into five categories. If the required combination of parameters is not in the table, the parameter by which the pipeline is assigned to a higher category is used (Appendix N 3).

2.4.4. For technological pipelines of categories I, II and III, as well as for pipelines of all categories transporting substances at a corrosion rate of more than 0.5 mm / year, the head of the installation must draw up a passport of the established sample (Appendix N 2).

List of documents attached to the passport:

a pipeline diagram indicating the conditional passage, the initial and rejection thickness of the pipeline elements, the installation locations of valves, flanges, plugs and other parts installed on the pipeline, the location of the drain, purge and drainage devices, welded joints (Appendix N 3);

act of revision and rejection of pipelines (Appendix N 4);

certificate of quality of repair of pipelines.

For the rest of the pipelines at each installation, it is necessary to keep an operational log, in which the dates of the audits carried out and data on the repairs of these pipelines should be recorded (Appendix No. 5).

2.4.5. For each installation, the person responsible for the safe operation of pipelines must draw up a list of critical technological pipelines, made in two copies: one is kept by the person responsible for the safe operation of pipelines, the other - in the technical supervision department (Appendix No. 6) .

2.4.6. During the operation of pipelines, one of the main duties of maintenance personnel is constant and careful monitoring of the condition of the outer surface of pipelines and their parts: welds, flange connections, including fasteners, fittings, insulation, drainage devices, compensators, supporting structures, etc. .P. The results of inspections should be recorded in the logbook at least once per shift.

Fig.5.

2.4.7. Supervision of the correct operation of pipelines is carried out daily by the engineering and technical staff of the facility, periodically - by the technical supervision service together with the person responsible for the safe operation of pipelines, at least once every 12 months.

Questions for reflection:

How are t / wires classified depending on the operating parameters and properties of the transported medium?

What technological t / wires need to have passports of the established sample?

Which technological t / wires need to have an operational log of the established sample?

2.5. Control methods

2.5.1. The main method of monitoring the reliable and safe operation of technological pipelines is periodic revisions, which are carried out by the technical supervision service together with mechanics and plant managers. The results of the audit serve as the basis for assessing the condition of the pipeline and the possibility of its further operation.

The timing of the revision of technological pipelines is indicated in the projects, in case of their absence, they are established by the OTN, depending on the rate of their corrosion and erosion wear, operating experience, the results of the previous external inspection, revision. The terms should ensure safe, accident-free operation of the pipeline between revisions and should not be less than those specified in Appendix 7.

When conducting an audit, special attention should be paid to areas operating in particularly difficult conditions, where the maximum wear of the pipeline due to corrosion, erosion, vibration and other reasons is most likely.

These include areas where the direction of flow changes (elbows, tees, tie-ins, drainage devices, as well as sections of pipelines before and after fittings) and where accumulation of moisture, substances that cause corrosion (dead ends and temporarily non-working sections) is possible.

2.5.2. Conduct an external inspection of the pipeline.

External inspection of pipelines laid in an open way can be carried out without removing the insulation. However, if the condition of the walls or welds of the pipelines is in doubt, at the direction of the employee of the technical supervision department, partial or complete removal of the insulation should be carried out.

If, during an external examination, leaks in detachable joints are found, the pressure in the pipeline must be reduced to atmospheric pressure, the temperature of hot pipelines - up to +60 ° C, and the defects must be eliminated in compliance with the necessary safety measures.

If defects are detected, the elimination of which is associated with hot work, the pipeline must be stopped, prepared for repair work in accordance with the instructions of the “Standard Instructions for the Organization of Hot Work at Explosive and Explosive and Fire Hazardous Facilities”, approved by Rostekhnadzor of the Russian Federation, and the defects are eliminated.

The person responsible for the safe operation of pipelines is responsible for the timely elimination of defects.

2.5.3. The wall thickness is measured in areas operating in the most difficult conditions (elbows, tees, tie-ins, places of narrowing of the pipeline, before and after fittings, places of accumulation of moisture and corrosive products that cause corrosion - stagnant zones, drainages), as well as in straight sections intrashop and intershop pipelines.

The number of measurement points for each section (element) is determined by the technical supervision department, provided that a reliable revision of pipelines is ensured.

On straight sections of pipelines of technological installations with a length of 20 m or less and inter-shop pipelines with a length of 100 m or less, wall measurements must be performed at least in 3 places. In all cases, measurement should be made at 3-4 points along the perimeter, and on bends at least 4-6 points along the convex and concave parts.

It is necessary to ensure the correctness and accuracy of measurements, to exclude the influence of foreign bodies (burrs, coke, corrosion products, etc.) on them. The measurement results are recorded in the pipeline passport.

2.5.4. Hammering method.

Pipelines of categories IV, V are mainly subjected to tapping with a hammer. Pipelines are tapped along the entire perimeter of the pipe with a hammer weighing 1.0-1.5 kg with a handle not less than 400 mm long with a spherical cap. The condition of the pipe is determined by the sound or dents that form during tapping. The issue of partial or complete removal of insulation during the audit is decided by the technical supervision service in each specific case, provided that a reliable audit is ensured. If the results of tapping cannot accurately judge the safe operation of the pipeline, it needs to measure the wall thickness.

An internal inspection of the pipeline section is carried out using an endoscope, a magnifying glass or other means, if as a result of measuring the wall thickness and tapping the pipeline there are doubts about its condition; In this case, the inner surface must be cleaned of dirt and deposits, and, if necessary, pickled. In this case, you should choose a site operated in adverse conditions (where corrosion and erosion, water hammer, vibration, changes in flow direction, formation of stagnant zones, etc.) are possible. The dismantling of a pipeline section in the presence of detachable connections is carried out by disassembling them, and this section is cut out on an all-welded pipeline. During the inspection, they check for corrosion, cracks, reduction in the thickness of the walls of pipes and pipeline parts.

Questions for reflection:

When conducting an audit of t / wires, which areas should be given special attention?

How many measurements of the wall thickness of a t / wire must be performed when conducting an audit on straight sections of pipelines of technological installations with a length of 20 m or less?

How many measurements of the wall thickness of a t / wire must be performed when conducting an audit on straight sections of inter-workshop pipelines with a length of 100 m or less?

How many wall thickness measurements should be taken on the bends?

What is the frequency of testing t / wires for strength and density?

The value of the rejection size for t / wire with an outer diameter of 57 mm?

The value of the rejection size for t / wire with an outer diameter of 108 mm?

What is the value of the rejection size for t / wire with an outer diameter of 219 mm?

What is the value of the rejection size for t / wire with an outer diameter of 325 mm?

2.5. Testing pipelines for strength and density.

2.5.1. Technological pipelines must be tested for strength and density before putting them into operation, after installation, repairs associated with welding, disassembly, after conservation or downtime for more than one year, when changing operating parameters, and also periodically within a period equal to double revision.

After disassembly of single flange connections, the pipeline associated with the replacement of gaskets, fittings or a separate element of the pipeline (tee, coil, etc.), it is allowed to test only for density. In this case, the newly installed fittings or pipeline element must first be tested for strength by test pressure.

Pipelines of groups A, B (a), B (b) except for tests for strength and density must be tested for tightness (additional pneumatic tightness test with determination of pressure drop during the test).

Air vents of individual devices and systems operating without excess pressure and sections of flare lines, as well as short discharge pipelines directly into the atmosphere from safety valves, are not tested for strength and density.

The pipeline strength and density test is carried out simultaneously, it can be hydraulic or pneumatic. Predominantly hydraulic testing should be used.

The test is usually carried out before the pipeline is covered with thermal or anti-corrosion insulation. It is allowed to test the pipeline with applied insulation, but in this case, the field joints are left open.

The type of test and the pressure during the test are indicated in the project for each pipeline. In the absence of design data, the type of test is chosen by the technical management of the enterprise (pipeline owner).

Before testing, an external inspection of pipelines is carried out. At the same time, they check the correct installation of the fittings, the ease of opening and closing the locking devices, as well as the removal of all temporary devices and the completion of all welding work and heat treatment (if necessary).

The pipeline should only be tested after it has been fully assembled on permanent supports or hangers, tie-ins, fittings, bosses, fittings, drains, drain lines and air vents have been installed.

The pressure during testing should be measured by at least two pressure gauges installed at the beginning and at the end of the pipeline being tested.

Pressure gauges used when testing process pipelines must be checked and sealed.

The testing of the pipeline is carried out under the guidance of the person responsible for the operation of the pipeline, in the presence of a representative of the organization that performed the work. The test results are recorded in the "Certificate of Quality" or an act (if the "Certificate" is not compiled), followed by a mark in the pipeline passport.

2.5.2. Carrying out hydrotesting.

Hydraulic testing of the pipeline for strength and density is carried out simultaneously.

For hydraulic testing, water is used at a temperature of +5 to +40 ° C or other non-corrosive, non-toxic, non-explosive, non-viscous liquids, such as kerosene, diesel fuel, light oil fractions.

At the same time, in order to avoid large losses of liquids and the rapid detection of leaks in the pipeline, careful supervision of possible leaks must be ensured.

If testing is required at sub-zero ambient temperatures, fluids whose freezing point is lower than the testing temperature listed above should be used.

To check the strength, the pipeline is kept under test pressure for 5 minutes, after which, for the density test, the pressure in it is reduced to that specified in Appendix 8.

To check the density at operating pressure, the pipeline is inspected and the welds are tapped with a hammer weighing 1-1.5 kg. Blows are applied to the pipe next to the seam on both sides.

Defects found during the inspection (cracks, pores, leaks in detachable joints and glands, etc.) are eliminated only after the pressure in the pipeline is reduced to atmospheric. After elimination of the detected defects, the test should be repeated. Undercutting of welded seams is prohibited.

With simultaneous hydraulic testing of several pipelines for strength, common load-bearing building structures should be checked.

The results of a hydraulic test for strength and density are considered satisfactory if during the test there was no pressure drop on the pressure gauge and no leakage and sweating appeared on the pipeline elements.

Questions for reflection:

What types of g / tests are carried out for t / wires of groups A, B (a), B (b)?

What pressure should be used to test the strength of t / wires operating with a pressure of more than 2 kg / cm 2?

What pressure should be used to test the density of t / wires operating with a pressure of more than 2 kg / cm 2?

What is the duration of the tightness test of t / wires of groups A, B (a), B (b)?

What is the allowable pressure drop during the tightness test of t / wires of groups B (a), B (b)?

For the repair of t / wires of what categories is it possible to use elements of t / wires that do not have certificates or passports?

For which t / wires is it possible to use fittings that do not have passports and markings?

2.6. Technical documentation for pipelines

The following technical documentation is maintained for technological pipelines:

1. List of critical technological pipelines for installation;

2. Passport of the pipeline;

3. Act of periodic external inspection of the pipeline;

4. The act of testing technological pipelines for strength and density;

5. Act for the repair and testing of fittings;

6.Operational journal of pipelines (maintained for pipelines for which a passport is not drawn up)

7. Journal of installation and removal of plugs;

8. Documentation for safety valves:

operational passport for PPK;

technical passport for PPK, technical passport of a cylindrical compression spring;

set pressure sheet

act of revision and adjustment.

The place of storage of technical documentation is determined by the factory instruction, depending on the structure of the enterprise.

4. Security questions

How are pipelines classified depending on the operating parameters and properties of the transported medium?

Which technological pipelines require standard passports?

Which technological pipelines need to have an operational log of the established sample?

How often do maintenance personnel need to make entries in the logbook on the results of inspection of pipelines?

When conducting an audit of pipelines, which sections should be given special attention?

How many measurements of the pipeline wall thickness should be performed when carrying out an audit on straight sections of pipelines of technological installations with a length of 20 m or less?

How many measurements of the pipeline wall thickness must be performed when conducting an audit on straight sections of inter-shop pipelines 100 m long or less?

How many wall thickness measurements should be taken on the bends?

What is the frequency of testing pipelines for strength and density?

The value of the rejection size for a pipeline with an outer diameter of 57 mm?

The value of the rejection size for a pipeline with an outer diameter of 108 mm?

What is the rejection size for a pipeline with an outer diameter of 219 mm?

What is the rejection size for a pipeline with an outer diameter of 325 mm?

What types of g / tests are carried out for pipelines of groups A, B (a), B (b)?

What environments are used to conduct g / tests?

What pressure should be used to test the strength of pipelines operating with a pressure of more than 2 kg / cm 2?

What pressure should be used to test the tightness of pipelines operating with a pressure of more than 2 kg / cm 2?

What is the duration of the tightness test of pipelines of groups A, B (a), B (b)?

What is the allowable pressure drop during the tightness test of pipelines of groups B (a), B (b)?

For the repair of pipelines, of what categories is it possible to use elements of pipelines that do not have certificates or passports?

For which pipelines is it possible to use fittings that do not have passports and markings?

Application No. 1.

Group

Name

R slave kgf / cm 2

T slave,

0 С

R slave kgf / cm 2

T slave,

0 С

R slave kgf / cm 2

T slave,

0 С

R slave kgf / cm 2

T slave,

0 С

R slave kgf / cm 2

T slave,

0 С

Substances with toxic effects:

a) extremely and highly hazardous substances of classes I and II (GOST 12.1.007-76) - benzene, acids, hydrogen sulfide, tetraethyl lead, phenol, chlorine

b) moderately hazardous substances of class III - ammonia, methyl alcohol, toluene, solutions of caustic alkalis (more than 10%)

c) freon

Independently

St.16

Vacuum below 0.8

Above 16

Independently

From +300 to +700 and below -40

Independently

-«-

Vacuum from 0.8 to 16

Up to 16

-40 to +300

Independently

Explosive and flammable substances according to GOST 12.1.004-76

a) combustible gases

b) Flammable liquids (flammable liquids) - acetone, gasoline, kerosene, oil, diesel fuel

c) Combustible liquids (LF) - fuel oil, oils, tar, asphalt, bitumen, oil distillates

Above 25

Vacuum 0.8

Above 25

Vacuum below 0.8

Above 63

Vacuum below 0.03

Independently

-«-

Above +300 and below -40

Above +300 and below -40

Above +350 and below -40

Above +350 and below -40

Vacuum 0.8

up to 25

Above 16 to 25

Vacuum below 0.95 to 0.8

Above 25 to 63

Vacuum below 0.08

-40 to +300

Up to 16

-40 to +300

Above +250 to +360

Too

-40 to +120

Above 16 to 25

Vacuum below 0.95 to 0.08

Above +120 to +250

-40 to +120

Up to 16

-40 to +120

Slow-burning (TG) and non-combustible substances (NG) according to GOST 12.1.044

Vacuum below 0.03

St. 63

Vacuum below 0.8

St.+350 to +450

St. 25 to 63

+250 to +350

St.16

up to 25

St.+120 to +250

Up to 16

-40 to +120

Application №2

Application №3

Application No. 4

Application No. 5

Operational log of non-certified pipelines

Table #1

No. p / p

Line name

Audit Frequency

Table number 2

No. p / p

Audit date

Information about the replacement and repair of the pipeline

Responsible person's signature

Application No. 6

Application No. 7

Transported

environments

pipeline

Inspection frequency at corrosion rate, mm/year

over 0.5

0,1-0,5

up to 0.1

Group A media

I and II

at least once a year

at least 1 time in 2 years

at least once every 3 years

Environments of groups B(a), B(b)

I and II

at least once a year

at least once a year

at least 1 time in 2 years

at least once every 3 years

at least once every 3 years at least once every 4 years

Environments of groups B (c)

I and II

III and IV

at least once a year

at least once a year

at least 1 time in 2 years

at least once every 3 years

at least once every 3 years

at least once every 4 years

Group B environments

I and II

III and IV,V

at least 1 time in 2 years

at least once every 3 years

at least once every 4 years

at least once every 6 years

at least once every 6 years

at least once every 6 years

Application No. 8.

Purpose of the pipeline

Pressure, kgf / cm 2

For strength

Per density

All process pipelines, except those specified in

p. 2,3,4

Rpr \u003d 1.12 Rrab * 20/  t

Rrab

Pipelines transporting combustible, toxic and liquefied gases at operating pressure:

• below 0.95 kgf / cm 2

  up to 0.05 kgf / cm 2

  from 0.05 to 0.5 kgf / cm 2

  from 0.5 (abs) to 2 kgf / cm 2

not produced

not produced

not produced

Rrab+0.3

P work but not lower than 0.85

Flare lines

Gravity pipelines

Application number 9.

Application No. 10

Scope of inspection of welded joints by ultrasonic or radiographic method in % of the total number welded by each welder (but not less than one joint)

Manufacturing conditions

When manufacturing a new or repairing an old pipeline

When welding dissimilar steels

When welding pipelines included in blocks of I category of explosion hazard

Appendix No. 11

Table 1.

Classification of pipelines Ru=< 10 Мпа (100 кг/см²)

General

Group

Transported

substances

Rrab., MPa

(kg/cm ² )

t work.,

°С

Rrab., MPa

(kg/cm ² )

t work.,

°С

Rrab., MPa

(kg/cm ² )

t work.,

°С

Rrab., MPa

(kg/cm ² )

t work.,

°С

Rrab., MPa

(kg/cm ² )

t work.,

°С

Substances with a toxic effect

a) extremely and highly dangerous substances of classes 1,2

(GOST 12.1.007)

b) moderately dangerous

class 3 substances

(GOST 12.1.007)

Regardless

Over 2.5

(25)

Regardless

Over +300

and below -40

Vaccum

from 0.08

(0,8)

(abs)

up to 2.5(25)

From -40

before

Explosive and flammable substances GOST 12.0.044.

a) combustible gases (GG),

including liquefied (LHG)

Over 2.5

(25)

Vaccum

below 0.08

(0,8)

(abs)

Over +300

and below -40

Regardless

Vaccum

from 0.08

(0,8)

(abs)

up to 2.5(25)

From -40

before

b) flammable liquids (flammable liquids)

c) flammable liquids (GZh)

Over 2.5

(25)

Vaccum

below 0.08

(0,8)

(abs)

Over 6.3

Vaccum

below 0.003

(0,03)

(abs)

Over +300

and below -40

Regardless

Over +350

and below -40

Same

Over 1.6(16) to 2.5(25)

Vaccum

above 0.08

(0,8)

(abs)

Over 2.5

(25) to

6,3 (63)

Vaccum

below 0.08

(0,8)

(abs)

From +120 to +300

From -40

up to +300

Over +250

up to +350

Same

Up to 1.6(16)

Over 1.6(16)

up to 2.5(25)

Vaccum

up to 0.08

(0,8)

(abs)

-40 to +120

Over +120

up to +250

-40 to +250

Up to 1.6(16)

-40 to +120

Flammable (TG)

and non-combustible substances (NG) according to GOST 12.1.044

Vaccum

below 0.003

(0,03)

(abs)

Over 6.3(63) vacuum below 0.08

(0,8)

(abs)

Over +350

up to +450

Over 2.5(25)

up to 6.3 (63)

From +250

before

Over 1.6(16)

up to 2.5 (25)

Over +120

up to +250

Up to 1.6 (16)

-40 to +120

Notes. 1 . The designation of the group of a certain transported medium includes the designation of the general group of the medium (A, B, C) and the designation of the subgroup (a, b, c), reflecting the hazard class of the transported substance.

2. The designation of the pipeline group in general terms corresponds to the designation of the group of the transported medium. The designation "pipeline of group A(b)" means a pipeline through which a medium of group A(b) is transported.

A group of a pipeline transporting media consisting of various components is established by component,

requiring the assignment of the pipeline to a more responsible group. At the same time, if the content in the mixture of hazardous

substances 1, 2 and 3 hazard classes, the concentration of one of the components is lethal, the group of the mixture is determined by this

substance.

In the event that the most dangerous component in terms of physicochemical properties is included in the composition of the mixture in an insignificant

quantity, the issue of assigning the pipeline to a less responsible group or category is decided by the design

The hazard class of hazardous substances should be determined according to GOST 12.1.005 and GOST 12.1.007, the values ​​of the fire and explosion hazard indicators of substances - according to the relevant NTD or the methods set forth in GOST 12.1.044.

For vacuum lines, it is not the nominal pressure that must be taken into account, but the absolute working pressure.

Pipelines transporting substances with a working temperature equal to or higher than their auto-ignition temperature or a working temperature below minus 40 ° C, as well as incompatible with water or air oxygen under normal conditions, should be assigned to category 1.

State Committee of the Russian Federation
on architecture and construction
(Gosstroy of Russia)

COLLECTIONS OF RESOURCE ESTIMATE NORMS
FOR INSTALLATION OF EQUIPMENT

Compilation 12

PROCESS PIPING

ReleaseI

put into action
letter from Gosstroy of Russia
dated May 5, 1994 No. VB-12-69

Moscow 1994

This collection was developed by AOPI Neftespetsstroyproekt, reviewed by the Central Research Institute for Economics and Construction Management (TsNIIEUS) and the Main Directorate for Pricing, Estimated Norms and Consumption of Building Materials of the Gosstroy of Russia.

TECHNICAL PART

1. This collection contains resource estimate norms (RSN) for the installation of technological pipelines and general-purpose pipeline fittings during the construction of new, expansion, reconstruction and technical re-equipment of existing industrial enterprises.

2. Technological pipelines include pipelines intended for transportation within an industrial enterprise or a group of these enterprises of raw materials, semi-finished products, finished products, auxiliary materials that ensure the conduct of the technological process and the operation of equipment (steam, water, air, gases, refrigerants, fuel oil, lubricants , emulsions, etc.), production waste from aggressive effluents, as well as return water supply pipelines.

3. Technological pipelines do not include pipelines for fire and drinking water supply, heating, sewage of non-aggressive drains and storm sewers.

4. In case of combined water supply (fire-fighting-industrial-drinking), as well as in the combined use of pipelines (if they transport gas, water, steam, etc.) intended for technological purposes and domestic needs, only sections for connection of devices and machines to the lines of combined and combined pipelines.

5. When determining the length of pipelines, their length along the entire route is taken into account, including the expanded length of U-shaped compensators and fittings of pipelines, with the exception of the construction length of fittings, lens and stuffing box compensators.

The average mass of 1 m of pipelines, assemblies and sections of pipelines is given in line 5 of the normative tables (in the average mass of 1 m of pipelines, the mass of brackets, supports and hangers is taken into account) and provides for average pipe wall thicknesses adopted in the development of a collection of 12 prices for equipment installation (RMO-91 ), SNiP 4.06-91. Average values ​​of thicknesses, walls of pipes are given in the following table.

	Wall thickness, mm
outer diameter,	Carbon steel and high quality		Alloy and high alloy steel
mm	Nominal pressure, no more than, MPa
1020
1220
1420

6. The RCH takes into account the costs of performing a full range of installation works, determined on the basis of the relevant technical conditions and instructions for the installation of process pipelines, including the costs of:

horizontal movement of pipes, fittings and other materials from the on-site warehouse to the installation site at a distance of up to 1000m;

hydraulic testing of pipelines.

7. The norms provide for work from the floor and inventory scaffolds up to 3 m high. When working from cradles and ladders, as well as on inventory scaffolds over 3 m high, a coefficient of up to 1.3 should be applied to the labor costs of workers and drivers and the time of using machines and mechanisms .

8. The norms provide for the performance of installation work using mobile cranes. When performing work with the help of overhead cranes, a correction factor of 0.76 should be applied to the labor costs of workers and machinists and the time of using machines and mechanisms, and with the help of electric winches or manually - 1.15.

When performing work with the help of electric winches, it is necessary to add to the norms of this collection the norms for the installation and removal of electric winches according to the collection 37 of the RSN "General Purpose Equipment".

9. The consumption of auxiliary materials, given in the RSN, is determined according to the production norms for the consumption of materials for installation and special construction work. The need for basic materials (pipes, assemblies, sections, parts, etc.) during the installation of pipelines should be determined according to the technical documentation. In the absence of technical documentation, the consumption of basic materials is recommended to be determined using the calculation method set out in Appendix 1 to this collection.

10. The RSN does not take into account the following works:

for departments 1 and 2 - manufacturing of pipeline parts; equipment, installation, removal of rigging equipment necessary for the production of installation work; construction work related to the installation (punching and sealing of holes, etc., with the exception of the installation and dismantling of scaffolds);

for departments 1, 2 and 5 - priming and painting of pipes, preliminary and concomitant heating of welded joints, heat treatment of welded joints of pipelines, etching of pipes with chemical reagents and other special treatments;

testing of welds by gamma fluoroscopy and other methods (ultrasound, etc.).

11. The average category of work on the installation of process pipelines is 4.

12. In the normative tables of this collection there is no link to the positions of the collection 12 RMO-91 (SNiP 4.06-91) due to differences in the construction of these collections.

13. The name "trailer", presented in the composition of machines and mechanisms, should be understood as a set consisting of a tractor and a semi-trailer.

14. Water consumption is not given in the normative tables and is determined according to the data presented in Appendix 2 to this collection.

15. In the RSN, the level of labor costs of workers and machinists, the time of use of machines and mechanisms is determined on the basis of the ENiR and VNiR, entered into force on January 1, 1987. it is recommended to apply a coefficient of up to 1.6 to labor costs and time of use of machines.

Ticket number 1

What is the maximum working pressure?

- permitted pressure for the apparatus to which the pipeline is connected;

- for pressure pipelines (after pumps, compressors, gas blowers) - the maximum pressure developed by a centrifugal machine with a closed valve on the discharge side; and for reciprocating machines - the response pressure of the safety valve installed on the pressure source;

- for pipelines with safety valves installed on them - the pressure of the safety valve.

3. Welded seams and their location from the edge of the support.

The design and location of welded joints should ensure their quality performance and control up to the axis of the circumferential weld for pipes;

Welded joints of pipelines must be located from the edge of the support at a distance of 50 mm for pipes with a diameter of less than 50 mm and at least 200 mm for pipes with a diameter of more than 50 mm.

In what cases is it allowed to replace a hydraulic test with a pneumatic one?

If the supporting building structure or supports are not designed to fill the pipeline with water;

When the ambient temperature is below 0°C and there is a risk of freezing of individual sections of the pipeline;

If the use of liquid (water) is unacceptable.

Ticket number 2

Scope "Rules for the construction and safe operation of technological pipelines".

- the rules apply to stationary steel technological pipelines intended for the transportation of gaseous, vaporous and liquid media in the range from a residual pressure (vacuum) of 0.001 MPa (0.01 kgf / cm 2) to a nominal pressure of 320 MPa (3200 kgf / cm 2) and operating temperatures from minus 196 to plus 700°С at chemical, petrochemical, oil refining, gas processing, chemical-pharmaceutical, pulp and paper, microbiological, coke-chemical, oil and gas producing enterprises.

What should an installer of technological pipelines of the 4th category be able to do?

Sharpening, refueling, adjusting, adjusting the tools used;

Use the necessary devices and measuring instruments;

Purpose of safety valves?

To prevent destruction of equipment;

Types of gasket materials used on flanged joints?

Paronite, asbestos, vinyl plastic;

Steel, copper, lead;

Ticket number 3

Which pipelines are divided into process pipelines depending on the operating pressure?

For low-pressure process pipelines with nominal pressure up to 10 MPa (100 kgf / cm 2) inclusive;

Technological high-pressure pipelines with a nominal pressure of over 10 MPa (100 kgf / cm 2) up to 320 MPa (3200 kgf / cm 2).

2. Which pipelines must be installed by a CT installer of the 4th category?

Installation of pipelines with a diameter of up to 200 mm for nominal pressure up to 4 MPa (40 atm.) with the installation of fittings.

3. Classification of gases pumped through pipelines?

Liquefied;

What is the purpose of an external centralizer when assembling pipelines?

Alignment of pipe ends during welding along the location axis;

Ticket number 4

What media are pumped products divided into depending on the corrosion rate of carbon steels?

Non-aggressive and slightly aggressive - with a corrosion rate of up to 0.1 mm / year;

Medium aggressive - with a corrosion rate of 0.1 - 0.5 mm / year;

Highly aggressive - with a corrosion rate of over 0.5 mm/year.

Responsibilities for the installation of pipelines from glass pipes of a 4th category process pipeline installer?

Installation and testing of pipelines made of glass labor with a diameter of more than 25 to 40 mm.

Installation of glass fittings and valves.

Cutting glass pipes on the machine.

By what value should the test pressure of pipelines exceed the working pressure?

How is a trench backfilled?

In two doses;

Ticket number 5

What needs to be checked before assembling parts into enlarged piping assemblies?

Marking;

Ticket number 6

1. Requirements for the design of the high pressure pipeline.

- parts of high-pressure pipelines should be made of forgings, forgings and pipes. It is allowed to use other types of blanks if, according to the conclusion of a specialized research organization, they provide reliable operation during the estimated service life, taking into account the specified operating conditions.

The ratio of the inner diameter of the branch to the inner diameter of the main pipe in forged tee inserts should not be less than 0.25. If the ratio of nozzle diameter to main pipe diameter is less than 0.25, tees or nozzles must be used.

Ticket number 7

1. What are the requirements for pipeline fittings according to the method of connection?

According to the method of connection to the pipeline, the fittings are divided into flanged, coupling, pin and welded.

Coupling and pin iron fittings are recommended only for pipelines with nominal diameter D y not more than 50 mm, transporting non-combustible neutral media. Coupling and pin steel fittings can be used on pipelines for all media with a nominal diameter D y of not more than 40 mm.

Flanged and welded fittings are allowed for use for all categories of pipelines.

Ticket number 8

1. What valves are pipeline valves divided into according to their operational purpose?

Shut-off

Regulatory

safety,

distribution,

protective,

Phase separation.

Ticket number 9

Ticket number 10

1. How is the pipeline flushed and purged?

Pipelines must be flushed or purged in accordance with the design guidelines.

Flushing can be done with water, oil, chemicals, etc.

Purging can be done with compressed air, steam or inert gas.

Flushing, purging of pipelines should be carried out according to a specially designed scheme.

When flushing (purging) in winter, measures must be taken to prevent freezing of pipelines. An act is drawn up on flushing and purging.

Washing with water should be carried out at a speed of 1 - 1.5 m / s.

After flushing, the pipeline must be completely emptied and purged with air or inert gas.

Purge of pipelines must be carried out at a pressure equal to the working one, but not more than 4 MPa (40 kgf / cm 2).

Purge of pipelines operating under excess pressure up to 0.1 MPa (1 kgf / cm 2) or vacuum must be carried out at a pressure of not more than 0.1 MPa (1 kgf / cm 2).

The duration of the purge, unless there are special instructions in the project, should be at least 10 minutes.

During flushing (purging), diaphragms, instrumentation, control and safety fittings are removed and coils and plugs are installed.

During flushing or purging of the pipeline, the fittings installed on the drain lines and dead ends must be completely open, and after flushing or purging is completed, carefully inspected and cleaned.

Mounting washers installed instead of measuring orifices can only be replaced with working orifices after flushing or purging the pipeline

Ticket number 1

What applies to process pipelines?

Process pipelines include:

- pipelines within industrial enterprises, through which raw materials, semi-finished products and finished products, steam, water, fuel, reagents and other substances are transported, ensuring the conduct of the technological process and the operation of equipment;

– inter-factory pipelines that are on the balance sheet of the enterprise.

A significant amount of construction of the main facilities in the oil refining, metallurgical, food industries is given to the arrangement of technological pipelines. They play a crucial role in the functioning of strategically important systems. Also, technological pipelines are used in agro-industrial complexes, heat supply systems and in many other industries.

Basic concepts

A pipeline is a device designed to transport a variety of substances. It consists of pipe sections, connecting and shut-off valves, automation and fasteners.

What is the meaning of the term "technological pipelines?" The definition designates them as supply systems for industrial enterprises through which semi-finished and finished products are transported, as well as substances that ensure the conduct of the entire process.

Location of pipelines

During the laying process, the following recommendations must be followed:

• technological pipelines should have a minimum length;
• sagging and stagnation are unacceptable in the system;
• providing free access for technological control;
• the possibility of locating the necessary lifting and transport vehicles;
• providing insulation to prevent moisture penetration and retain heat;
• protection of pipelines from possible damage;
• unhindered movement of fire extinguishing equipment and lifting mechanisms.

Draft angles

The operation of technological pipelines provides for forced shutdowns. To do this, slopes are laid in the project, which will ensure arbitrary emptying of pipes. The device of technological pipelines provides the following slope angle depending on the medium being transported (values ​​are given in degrees):

• gaseous medium: in the direction of movement - 0.002, against it - 0.003;
• liquid highly mobile substances - 0.002;
• acidic and alkaline environment - 0.005;
• substances of high viscosity or quick-setting - up to 0.02.

The design may not provide for a slope, then special measures must be taken to empty the pipelines.

Preparatory work

Installation of technological pipelines must be accompanied by the following steps:

Route marking

This operation consists in transferring the axes of fastening of fittings and compensators directly to the place where technological pipelines will be laid. Determination of the markup location can be performed by the following tools:

• roulettes;
• plumb lines;
• level;
• hydraulic level;
• templates;
• squares.

If a large number of technological pipelines are laid for a building, the time allotted for marking is significantly reduced due to the use of special layouts. They give a visual representation of the location of the pipeline lines in relation to the building structure. After marking, all applied elements are compared with the project, after which they begin to fix the supporting structures.

Installation of supports and fasteners

During the arrangement of the foundation of the building, holes must be provided in it for laying bolts, fastening supports. They can be made by mechanized equipment. During the installation of supports, the following recommendations should be taken into account:

1. Technological pipelines, which have fixed supports, described above, require the installation of fasteners in close proximity to the apparatus and fittings. on such supports should be tightly fixed, not allowing shifts. The same requirements apply to clamps.
2. Movable supports are mounted with the possibility of unimpeded movement of the pipeline in order to easily extend it if necessary. Also, provision must be made for the safety of thermal insulation during potential movement from expansion.
3. All installation supports must be checked by the installer of process pipelines for compliance with the horizontal and vertical. Possible deviations are foreseen, which cannot exceed the following limits:

• intrashop pipelines - ± 5 mm;
• external systems - ±10 mm;
• slopes - 0.001 mm.

Insertion into existing systems

Special permits are required for this, and a process piping installer who maintains these lines must be present at the work site. Insertion is carried out when a new mounted component is connected to an existing system. Usually, for such cases, the installation of shut-off equipment is provided, but if there is none in the existing system, then they resort to a tie-in. There are several features here:

1. The existing pipeline must be disconnected and emptied.
2. Pipes through which a flammable and explosive medium was transported must be neutralized and washed.
3. The fitting to be welded must pass preliminary tests. The steel grade is also established according to the documentation.
4. Welding work must be carried out by a highly qualified specialist who has a special permit for critical structures.
5. Before installation of process pipelines begins, the connecting assembly must pass all tests.

Purging and flushing

The assembled pipeline is subjected to cleaning, the method of which depends on the size of the pipe:

• diameter up to 150 mm - washed with water;
• over 150 mm - purged with air;

The area to be cleaned must be isolated from other pipelines with plugs. Flushing with water is carried out until water begins to flow from the pipe without contamination. Purge is carried out for 10 minutes. These methods are used if the technology does not provide for other cleaning standards. After the work done, you can proceed to the tests, which are performed in two ways: hydraulic and pneumatic.

Hydraulic tests

Before checking, technological pipelines are divided into separate conditional sections and the following activities are carried out:

• control by external inspection;
• verification of technological documentation;
• installation of air valves, temporary plugs (the use of permanent equipment is prohibited);
• shutdown of the test segment;
• connecting the test section to a hydraulic pump.

Thus, the strength and density of the pipeline are checked simultaneously. To establish the degree of strength, the special value of the test pressure is taken into account:

• Steel pipelines operated at operating pressures up to 5 kgf/m². The value of the test parameter is 1.5 of the working pressure, but not less than 2 kgf / m².
• Steel pipes operating at pressures exceeding 5 kgf/m². The value of the test parameter will be 1.25 working pressure;
• Cast iron, polyethylene and glass - 2 kgf / m².
• Non-ferrous metal pipelines - 1 kgf / m².
• For pipes made of other materials - 1.25 working pressure.

The holding time under the set pressure value will be 5 minutes, only for glass pipelines it is quadrupled.

Pneumatic tests

For testing, either an inert gas is used, which is taken from factory networks or from portable compressors. This option is preferred in cases where hydraulic tests are not possible for a number of reasons: lack of water, very low air temperature, and also when dangerous stresses can arise in the pipeline structure from the weight of water. The value of the ultimate test pressure depends on the size of the pipeline:

• with a pipe diameter of up to 200 mm - 20 kgf / m²;
• 200-500 mm - 12 kgf / m²;
• over 500 mm - 6 kgf / m².

If the pressure limit is different, special test instructions should be developed for such conditions.

Pneumatic test requirements

Pneumatic testing is prohibited for ground cast iron and glass structures. For all other materials from which process pipelines can be made, there are special requirements for testing:

• the pressure in the pipeline increases gradually;
• inspection can be carried out when the pressure reaches 0.6 of the working value (it is unacceptable to increase it during work);
• Leak testing is carried out by coating with soapy water; tapping with a hammer is prohibited.

The results of hydraulic and pneumatic tests are considered satisfactory if during their implementation there was no pressure drop on the pressure gauge.

Transfer of pipelines to operation

At all stages of installation, relevant documents are drawn up, fixing the types of work, tolerances, tests, etc. They are transferred at the stage of delivery of pipelines as accompanying documentation, they include:

• acts of delivery of supporting structures;
• certificates for welding consumables;
• protocol for internal cleaning of the pipeline;
• certificates of quality control of welded joints;
• conclusion on the testing of valves;
• acts and density;
• a list of welders who performed the connections, and documents confirming their qualifications;
• schemes of pipeline lines.

Technological pipelines are put into operation along with industrial installations, buildings and structures. Separately, only intershop systems can be rented out.

Periodic control should include the following operations:

1. Checking the technical condition during external inspection and non-destructive methods.
2. Checking areas subject to vibration with special devices that determine its frequency and amplitude.
3. Troubleshoot issues that have been identified during previous checks.

Equally important is the safe operation of process pipelines, which is ensured by compliance with all established rules.

Monthly system health checks should cover the following:

• flange connections;
• welds;
• insulation and coating;
• drainage systems,
• support fasteners.

If leaks are detected, for safety reasons, the operating pressure must be reduced to atmospheric pressure, and the temperature of the heating lines must be lowered to 60 ° C to carry out the necessary troubleshooting measures. The results of the check should be recorded in special journals.

revision

This is used to determine the condition and operational capabilities of pipelines. It is advisable to conduct an audit in areas where the operation of technological pipelines is carried out in particularly difficult conditions. The latter include vibration, increased corrosion.

The audit of pipelines includes the following operations:

1. Checking the thickness of the structure by non-destructive methods.
2. Measurement of areas subject to creep.
3. Inspection of welded joints that are in doubt.
4. Examination
5. The condition of the anchorages.

The first revision control should be carried out after a quarter of the period specified in the regulatory documents, but no later than 5 years after the launch of the facility. As a result of the timely conduct of all checks, the safe operation of process pipelines will be ensured.