Installation of bales on the gas pipeline distance. TTK. Installation of control and measuring points (CIP) during the construction of means of electrochemical protection of the gas pipeline. What is included in the work
UD 01 Instrumentation
Topic 2.1 Lesson 65-66 Installation of instrumentation on pipelines.
REQUIREMENTS FOR THE INSTALLATION OF REFRIGERATING PLANT AUTOMATION SYSTEMS
Instruments and automation equipment installed directly in the room of the refrigeration plant must comply with the requirements for class B-1b rooms. Instruments and means of automation that do not meet these requirements must be installed in a room adjacent to the refrigeration plant, convenient for viewing from the engine room and having excess ventilation.
The installation locations of the devices must provide reliable control or regulation of the relevant parameters, easy accessibility service personnel and good visibility of instrument settings. Devices and means of automation should be installed so that their vibration is minimal.
For ease of maintenance, all automation devices mounted in refrigeration pipelines must be separated by shut-off valves on both sides. It is not recommended to mount any additional panels or devices on the factory-made consoles or panels. All mounted protective automation devices must be set to a value that differs from the normal value of the controlled parameter by 10-15%.
The points for taking pressure pulses on the compressors must always be located in front (along the ammonia vapor path) of the suction and discharge valves. On the intermediate vessel, all three level controls are mounted on the same column. On horizontal receivers of the RD type, the level switch is mounted on special columns. On linear receivers, the level switch is mounted without a column. In evaporators, the level switches are mounted on the columns, and the sensors of the temperature regulators are mounted on the inlet or outlet pipelines of the coolant. Level switches are mounted on oil separators without a special column.
Pumps must be properly installed. check valves and connection of the pressure switch.
It is necessary to carefully check the compliance of the performed external connections with the diagrams. internal connections devices or actuators. Such a check is carried out by checking the electrical circuits using the device. Continuity testing of circuits can be performed successfully if the possibility of bypass circuits is excluded, in addition to the one that is currently being tested. Pay special attention to this and disconnect the circuits under test from the rest. When checking the installation, it is necessary to ring all the reserve cores.
The condition of the insulation is checked using a 500 or 1000 V megger. When checking the insulation, care must be taken not to apply high voltage on parts with reduced test voltage (electrolytic capacitors, semiconductor devices, low current telephone equipment, etc.). These parts must be shorted or disconnected depending on the circuit.
The state of insulation is considered normal if its electrical resistance complies with the requirements of the "Electrical Installation Rules" (PUE).
Wires and cables must be laid only with copper conductors. Wires leading to resistance thermometers, PRU and ROS sensors, gas analyzer sensors, solenoid valves and other circuits with a voltage of 220 V AC cannot be laid in one pipe.
Devices and means of automation should be installed in places that are easily accessible for maintenance.
The RKS relay should be installed strictly according to the instructions: the "plus" of the device is connected to the side high pressure, and "minus" - to the side of low pressure.
The PRU sensor column should be installed strictly according to the project and in accordance with fire safety requirements. Cable entries into panels, consoles, junction boxes and automation devices must be sealed as required by the PUE for explosive premises. Cables and wires must have marking tags.
ROUTING
INSTALLATION OF CONTROL AND MEASURING POINTS (CIP) DURING CONSTRUCTION
I. SCOPE
1.1. Typical technological map (hereinafter referred to as TTK) - complex normative document, which establishes, according to a specific technology, the organization of work processes for the construction of a structure using the most modern means mechanization, progressive designs and methods of performing work. They are designed for some average working conditions. The TTK is intended for use in the development of Projects for the production of works (PPR), other organizational and technological documentation, as well as for the purpose of familiarizing (training) workers and engineering and technical workers with the rules for performing work on the installation of control and measuring points (hereinafter referred to as instrumentation).
1.2. This map provides instructions on the organization and technology of work on the installation of control and measuring points, rational means of mechanization, provides data on quality control and acceptance of work, requirements industrial safety and labor protection in the course of work.
1.3. The regulatory framework for the development of technological maps are: SNiP, SN, SP, GESN-2001 ENiR, production norms for the consumption of materials, local progressive norms and prices, norms for labor costs, norms for the consumption of material and technical resources.
1.4. The purpose of creating the TC is to describe solutions for the organization and technology of the production of work on the installation of instrumentation in order to ensure their High Quality, as well as:
Reducing the cost of work;
Reducing the duration of construction;
Ensuring the safety of work performed;
Organization of rhythmic work;
Unification of technological solutions.
1.5. Work technological maps(RTK) for the performance of certain types of work. Working technological maps are developed on the basis of standard maps for the specific conditions of a given construction organization, taking into account its design materials, natural conditions, the existing fleet of machines and tied to local conditions. Working technological maps regulate the means of technological support and the rules for implementation technological processes during the production of works. Design features for the installation of instrumentation are decided in each case by the Working Design. The composition and level of detail of materials developed in the RTC are established by the relevant contractor construction organization, based on the specifics and scope of work performed. Working flow charts are reviewed and approved as part of the PPR by the head of the General Construction Contractor, in agreement with the Customer's organization, the Customer's Technical Supervision.
1.6. The technological map is intended for foremen, foremen and foremen who carry out work on the installation of instrumentation during the construction of electrochemical protection of the gas pipeline, as well as employees of the technical supervision of the Customer and is designed for specific conditions for the performance of work in the III temperature zone.
II. GENERAL PROVISIONS
2.1. The technological map was developed for a set of works on the installation of instrumentation.
2.2. Instrumentation installation work is carried out in one shift, the working hours during the shift are:
where 0.828 is the coefficient of use of mechanisms in time during the shift (the time associated with preparing for work and conducting ETO - 15 minutes, breaks associated with the organization and technology production process and rest for the driver - 10 minutes every hour of work).
2.3. The technological map provides for the performance of work by an integrated mechanized unit using the EO-2621 single-bucket excavator with a bucket capacity of 0.25 m https://pandia.ru/text/80/369/images/image003_57.jpg Installation of control and measuring points (CIP) during the construction of means of electrochemical protection of the gas pipeline" width="422 height=260" height="260">!}
Fig.1. Single-bucket excavator EO-2621
2.4. Instrumentation installation works include:
Geodetic breakdown of the location;
Digging a pit;
Connection of cathode and control leads to the pipeline;
Installation of reference electrodes;
Backfilling of the pit;
Instrumentation installation;
Connection of cables, wires of the reference electrode.
2.5. The control and measuring point is a column made of polymer material, shaped like a trihedron, 2500 mm long with a mounting plate protected from dust and moisture. The number of instrumentation, their brand and location on the gas pipeline route are determined by the Working Design. With stationary instrumentation, current-measuring and marker points are combined.
2.6. Current-measuring checkpoints are installed on average after 5.0 km, as well as on both sides of the case when crossing the road and railway. The following are connected to the mounting shield of the current-measuring control point:
Cable from long-term reference electrodes;
Cable from electrochemical potential sensors (auxiliary electrode) and corrosion rate sensors;
Measuring cable from the pipeline (cathode terminal);
Current-measuring cables welded to the gas pipeline at a distance of 30.0 m from the point.
2.7. Marker points are designed to link the data of planned in-pipe flaw detection, they are installed after 2.0-3.0 km along the gas pipeline route. Cables welded to the gas pipeline at the instrumentation installation site and directly to the marker pads installed in pairs 5.0 m from the instrumentation are connected to the mounting plate of such instrumentation.
2.8. Work should be carried out in accordance with the requirements of the following regulatory documents:
SP 48.13330.2011. Organization of construction;
SNiP 3.02.01-87. Earthworks, foundations and foundations;
SNiP 3.05.06-85. Electrical devices;
SNiP III-42-80*. Main pipelines;
SNiP 12-03-2001. Labor safety in construction. Part 1. General requirements;
Compressors, heat exchange equipment, auxiliary equipment refrigeration units are interconnected by connecting pipelines through which the refrigerant circulates.
In refrigeration plants, in addition to refrigerant piping, there are piping systems for circulating intermediate coolant, lubricating oil, cooling water, heating steam and compressed air necessary for the operation of instrumentation. The specifics of each type of pipeline determines the type of pipes used, the type of fasteners and connections.
For ammonia and freon pipelines with a diameter of more than 20 mm, seamless steel pipes are used: cold-drawn, produced in sections 9 m long and with an outer diameter of 20 to 50 mm, and hot-rolled, with a length of 4 ÷ 12.5 m and an outer diameter of 57 ÷ 426 mm. Seamless pipes the most hermetic and withstand high pressures. For small freon machines, copper pipes with conditional passage 3÷20 mm. Inner surface pipelines installed for refrigerant systems must be cleaned of scale and degreased.
For the circulation of the coolant and water, water and gas pipelines and steel pipes are used. welded pipes. Water and gas pipes are steel and cast iron. Sewerage at refrigeration stations is made of cast-iron socket pipes.
For oil pipelines of freon installations, copper pipelines are also used, for ammonia - steel.
Pipe links are assembled into pipeline systems in the following ways: by welding; flange connection; flare connection copper pipes; nipple connection; socket connection (for cast iron pipes); rolled couplings (for water and gas pipes). Pipelines with shutoff valves, instruments and equipment are connected by flanges or nipples.
For ammonia and freon pipelines with a diameter of 20 mm or more, paired socket-ledge flange connections are used, sealed with a paronite gasket (Fig. 60).
Nipple connections with a screw fitting 1 (Fig. 61) are also used for ammonia and freon lines, the connection of a flanged pipe with a nut 1 (Fig. 62) is only for freon lines.
Rice. 62. Connection of flanged pipes:
1 - nut, 2 - temporary plug, 3 - fitting
For all types of pipelines of refrigeration stations, the main type of connection is butt welding of pipes.
A socket connection and a threaded connection with a coupling are used on water mains.
For the installation of communications of refrigeration stations, shaped parts of pipelines are used: tees, bends, transitions, couplings, crosses, elbows, branch pipes.
Elbows, bends and transitions large diameter welded from individual segments cut from a steel sheet.
The following types of pipeline laying are distinguished: open, underground, in impassable and through channels.
Proper fastening of pipelines - important condition their normal operation. Pipelines are fixed with fixed and movable supports and hangers.
Movable fasteners, in addition to the main purpose - transferring the weight of pipelines to the building structure, provide freedom of movement of the pipeline point supported by them. Fixed fasteners fix the pipeline and transfer it to building construction all efforts not perceived by movable fasteners.
Fixed fasteners divide the pipeline into sections, inside which the temperature compensation of the pipeline takes place. These fasteners are made strong and stable, as they perceive heavy loads.
Fastening elements of the refrigerant and brine pipelines are made taking into account the thickness of the heat-insulating layer.
Fixed supports are made in the form of a metal pad welded to the base. The pipeline is rigidly pulled to the pillow with a clamp. The best type of movable supports - spring.
Sections of pipelines in different areas systems must ensure reliable, economical operation of apparatus and installations.
With underestimated diameters of pipelines, the speeds of movement of vapors and liquids increase, noise arises, losses from pipe resistance increase, and, consequently, energy costs. The optimal speeds in pipelines are in m/s:
test questions
1. List the pipes used in refrigeration plants.
2. What is the advantage of welded joints?
3. What kinds of pipe connections do you know?
4. Tell us about the nipple connection of pipes.
5. Why is seamless pipe used for refrigerant lines?
6. What types of pipeline fastenings do you know?
7. Name the types of valves.
8. Tell us about the principle of operation and the purpose of the control valve.
9. What are the features of freon valves?
10. What is a bellows valve?
11. Name the types of gate valves.
12. List the types of valve spindle drive.
13. What are non-return and safety valves used for?
14. What material are gaskets and stuffing boxes for ammonia and freon made of?
Bibliography
http://www. proffholod. en
http://www. brr. en
In hydraulic fracturing, the following instrumentation is used to control the operation of equipment and measure gas parameters:
- thermometers for measuring gas temperature;
- indicating and recording (self-recording) pressure gauges for measuring gas pressure;
- devices for registering pressure drop on high-speed flow meters;
- gas consumption meters (gas meters or flow meters).
All instrumentation must be subject to state or departmental periodic verification and be always ready to take measurements. Readiness is ensured by metrological supervision. Metrological supervision consists in the implementation of constant monitoring of the state, working conditions and the correctness of instrument readings, the implementation of their periodic check, withdrawal from operation of devices that have become unusable and have not passed inspection. Instrumentation should be installed directly at the measurement site or on a special instrument panel. If the instrumentation is mounted on the instrument panel, then one instrument with switches is used to measure readings at several points.
Instrumentation is connected to gas pipelines steel pipes. Impulse tubes are connected by welding or threaded couplings. All instrumentation must have the hallmarks or seals of the Rosstandart authorities.
instrumentation with electric drive, as well as telephone sets must be explosion-proof, otherwise they are placed in a room isolated from the hydraulic distribution unit.
The most common types of instrumentation in hydraulic fracturing include the instruments discussed later in this section.
Instruments for measuring gas pressure are divided into:
- on liquid devices, in which the measured pressure is determined by the value of the balancing liquid column;
- spring devices, in which the measured pressure is determined by the amount of deformation of the elastic elements ( tubular springs, bellows, membranes).
Liquid manometers are used to measure excess pressures up to 0.1 MPa. For pressures up to 10 MPa, the pressure gauges are filled with water or kerosene (at negative temperatures), and when measuring higher pressures, with mercury. Liquid pressure gauges also include differential pressure gauges (differential pressure gauges). They are used to measure pressure drop.
Differential pressure gauge DT-50(picture below), Thick-walled glass tubes are firmly fixed in the upper and lower steel blocks. At the top, the tubes are connected to trap chambers that prevent the tubes from escaping mercury in the event of an increase in maximum pressure. Needle valves are also located there, with the help of which you can disconnect the glass tubes from the measured medium, purge the connecting lines, and also turn off and turn on the differential pressure gauge. Between the tubes there is a measuring scale and two pointers that can be set to the upper and lower levels of mercury in the tubes.
Differential pressure gauge DT-50
a - design; b - channel layout; 1 - high pressure valves; 2, 6 - pads; 3 - camera traps; 4 - measuring scale; 5 - glass tubes; 7 - pointer
Differential pressure gauges can also be used as ordinary pressure gauges for measuring excessive gas pressures, if one tube is led into the atmosphere, and the other into the measured medium.
Pressure gauge with single-coil tubular spring(picture below). A curved hollow tube is fixed with its lower fixed end to a fitting, with the help of which the pressure gauge is connected to the gas pipeline. The second end of the tube is sealed and pivotally connected to the rod. The gas pressure through the fitting is transmitted to the tube, the free end of which through the rod causes the movement of the sector, gear and axle. The spring hair ensures the grip of the gear wheel and the sector and the smoothness of the arrow. A shut-off valve is installed in front of the pressure gauge, which allows, if necessary, to remove the pressure gauge and replace it. Pressure gauges during operation must pass state verification once a year. Operating pressure, measured by a pressure gauge, should be in the range from 1/3 to 2/3 of their scale.
Pressure gauge with single-coil tubular spring
1 - scale; 2 - arrow; 3 - axis; 4 - gear; 5 - sector; 6 - tube; 7 - thrust; 8 - spring hair; 9 - fitting
Self-recording pressure gauge with a multi-turn spring (figure below). The spring is made in the form of an oblate circle with a diameter of 30 mm with six turns. Due to the large length of the spring, its free end can move by 15 mm (for single-turn pressure gauges - only by 5-7 mm), the angle of untwisting of the spring reaches 50-60 °. This design allows the use of the simplest lever transmission mechanisms and automatic recording of readings with remote transmission. When the pressure gauge is connected to the measured medium, the free end of the lever spring will turn the axis, while the movement of the levers and rod will be transmitted to the axis. A bridge is fixed on the axis, which is connected to the arrow. The change in pressure and the movement of the spring through the lever mechanism are transmitted to the arrow, at the end of which a pen is installed to record the measured pressure value. The chart is rotated by clockwork.
Scheme of a self-recording pressure gauge with a multi-turn spring
1 - multi-turn spring; 2, 4, 7 - levers; 3, 6 - axes; 5 - thrust; 8 - bridge; 9 - arrow with a pen; 10 - cartogram
Float differential pressure gauges.
Float differential pressure gauges (Figure below) and narrowing devices are widely used in the gas industry. Constriction devices (diaphragms) are used to create a pressure drop. They work in conjunction with differential pressure gauges that measure the created pressure drop. At a steady gas flow rate, the total energy of the gas flow is the sum of potential energy (static pressure) and kinetic energy, i.e. velocity energy.
Before the diaphragm, the gas flow has an initial speed ν 1 in a narrow section, this speed increases to ν 2, after passing through the diaphragm, the tray expands and gradually restores its previous speed.
With an increase in the flow velocity, its kinetic energy increases and, accordingly, the potential energy, that is, the static pressure, decreases.
Due to the pressure difference Δp = p st1 - p st2, the mercury in the differential pressure gauge moves from the float chamber into the glass. As a result, the float located in the float chamber descends and moves the axis, with which the arrows of the device showing the gas flow are connected. Thus, the differential pressure across a throttling device, measured with a differential pressure gauge, can serve as a measure of gas flow.
Float differential pressure gauge
a - structural diagram; b - kinematic scheme; c - graph of changes in gas parameters; 1 - float; 2 - shut-off valves; 3 - diaphragm; 4 - glass; 5 - float chamber; 6 - axis; 7 - impulse tubes; 8 - annular chamber; 9 - pointer scale; 10 - axes; 11 - levers; 12 - pen bridge; 13 - pen; 14 - diagram; 15 - clock mechanism; 16 - arrow
The relationship between pressure drop and gas flow is expressed by the formula
where V is the volume of gas, m 3; Δp - pressure drop, Pa; K is a coefficient constant for a given aperture.
The value of the coefficient K depends on the ratio of the diameters of the aperture of the diaphragm and the gas pipeline, the density and viscosity of the gas.
When installed in a gas pipeline, the center of the diaphragm opening must coincide with the center of the gas pipeline. Diaphragm opening on the gas inlet side cylindrical shape with a conical extension to the flow outlet. The diameter of the inlet of the disk is determined by calculation. The leading edge of the disc hole must be sharp.
Normal diaphragms can be used for gas pipelines with a diameter of 50 to 1200 mm, subject to 0.05< m < 0,7. Тогда m = d 2 /D 2 где m - отношение площади отверстия диафрагмы к поперечному сечению газопровода; d и D - диаметры отверстия диафрагмы и газопровода.
Normal diaphragms can be of two types: chamber and disk. To select more accurate pressure pulses, the diaphragm is placed between the annular chambers.
The plus vessel is connected to the impulse tube, which takes pressure to the diaphragm; the negative vessel is supplied with pressure taken after the diaphragm.
In the presence of gas flow and pressure drop, part of the mercury is squeezed out of the chamber into a glass (figure above). This causes the float to move and, accordingly, the arrow indicating the gas flow, and the pen, which marks the magnitude of the pressure drop on the diagram. The chart is driven by a clock mechanism and makes one revolution per day. The scale of the diagram, divided into 24 parts, allows you to determine the gas flow rate for 1 hour. safety valve, which separates vessels 4 and 5 in the event of a sudden pressure drop and thus prevents a sudden release of mercury from the device.
The vessels communicate with the impulse tubes of the diaphragm through shut-off valves and an equalizing valve, which must be closed in the working position.
Bellows pressure gauges(figure below) are designed for continuous measurement of gas flow. The operation of the device is based on the principle of balancing the pressure drop by the forces of elastic deformations of two bellows, a torsion tube and helical coil springs. The springs are replaceable, they are installed depending on the measured pressure difference. The main parts of the differential pressure gauge are the bellows block and the indicating part.
Schematic diagram of a bellows differential pressure gauge
1 - bellows block; 2 - positive bellows; 3 - lever; 4 - axis; 5 - throttle; 6 - minus bellows; 7 - replaceable springs; 8 - stock
The bellows block consists of interconnected bellows, the internal cavities of which are filled with liquid. The liquid consists of 67% water and 33% glycerin. The bellows are interconnected by a rod 8. An impulse is supplied to the bellows 2 before the diaphragm, and to the bellows 6 - after the diaphragm.
Under the action of a higher pressure, the left bellows is compressed, as a result of which the liquid in it flows through the throttle into the right bellows. The rod, rigidly connecting the bottoms of the bellows, moves to the right and, through the lever, rotates the axis kinematically connected with the pointer and pen of the recording and indicating instrument.
The throttle regulates the flow rate of the liquid and thereby reduces the effect of pressure pulsation on the operation of the device.
Replaceable springs are used for the corresponding measurement limit.
Gas meters. Rotary or turbine meters can be used as counters.
In connection with the mass gasification industrial enterprises and boiler rooms, an increase in the types of equipment, it became necessary to measuring instruments with a big throughput and a significant measurement range at small overall dimensions. These conditions are more satisfied with rotary counters, in which 8-shaped rotors are used as a converting element.
Volumetric measurement in these meters is carried out due to the rotation of two rotors due to the difference in gas pressure at the inlet and outlet. The pressure drop in the meter required for the rotation of the rotors is up to 300 Pa, which makes it possible to use these meters even at low pressure. The domestic industry produces meters RG-40-1, RG-100-1, RG-250-1, RG-400-1, RG-600-1 and RG-1000-1 for nominal gas flow rates from 40 to 1000 m 3 / h and pressure not more than 0.1 MPa (in the SI system, the flow rate is 1 m 3 / h \u003d 2.78 * 10 -4 m 3 / s). If necessary, parallel installation of meters can be used.
Rotary counter RG(picture below) consists of a body, two profiled rotors, a box gear wheels, reducer, account mechanism and differential pressure gauge. Gas through the inlet pipe enters the working chamber. In the space of the working chamber, rotors are placed, which are driven under the pressure of the flowing gas.
Scheme of a rotary counter type RG
1 - counter housing; 2 - rotors; 3- differential pressure gauge; 4 - pointer of the counting mechanism
When the rotors rotate, a closed space is formed between one of them and the chamber wall, which is filled with gas. Rotating, the rotor pushes the gas into the pipeline. Each rotation of the rotor is transmitted through a box of gears and a gearbox to a counting mechanism. Thus, the amount of gas passing through the meter is taken into account.
The rotor is prepared for operation as follows:
- remove the upper and lower flanges, then wash the rotors with a soft brush dipped in gasoline, turning them with a wooden stick so as not to damage the polished surface;
- then both gear boxes and gearbox are washed. To do this, fill in gasoline (through the top plug), turn the rotors several times and drain the gasoline through the bottom plug;
- after washing, pour oil into the gear boxes, gearbox and counting mechanism, pour the appropriate liquid into the meter pressure gauge, connect the flanges and check the meter by passing gas through it, after which the pressure drop is measured;
- then they listen to the operation of the rotors (they must rotate silently) and check the operation of the counting mechanism.
At technical inspection they monitor the oil level in the gear boxes, gearbox and counting mechanism, measure the pressure drop, check the counters for tightness. Meters are installed on vertical sections of gas pipelines so that the gas flow is directed through them from top to bottom.
Turbine counters.
In these meters, the turbine wheel is driven by the gas flow; the number of revolutions of the wheel is directly proportional to the flowing volume of gas. In this case, the number of revolutions of the turbine through a reduction gear and a magnetic coupling is transmitted to a counting mechanism located outside the gas cavity, showing the total volume of gas that has passed through the device under operating conditions.
Control and measuring points (CIP) are points that are intended to provide access to conductors in the conditions of measuring the values of protective potentials, to control these protective potentials metal structures and structures laid below ground level, and designation of pipeline routes, as well as to ensure joint electrochemical protection of pipelines and other structures located underground from corrosion.
Instrumentation has a wide scope and is used:
On linear parts of main pipelines;
At the intersection of main pipelines;
At the intersection of pipelines with communication cables;
At the intersection of pipelines with high-voltage power lines;
At the intersections of the pipeline with automobile and railways(when used for pipeline protection casing);
On anode ground electrodes;
On installations of sacrificial protection of pipelines;
On electrically insulating inserts (couplings).
Structurally, it is made in the form of a rack with a base for fixing in the ground, on which a cabinet is mounted, in which there is a door for access to a textolite plate (terminal terminal), on which control clamps and manual adjustment elements are located. The instrumentation is additionally equipped with a kilometer mark, which allows you to visually determine the pipeline route from the air.
It is possible to manufacture the instrumentation rack from polyvinyl chloride (PVC), fiberglass or metal. The materials used are specially designed for outdoor use in all climatic zones. To prevent the theft of the rack, or the free removal of the control and measuring point from the ground, the instrumentation rack is equipped with an anchor device.
The terminal terminal, depending on the instrument model, is intended for installation of up to 18 terminal clamps and is made of polycarbonate. Contact clamps can be made from of stainless steel or brass. These clamps can allow the connection of conductors with a cross section of up to 16 mm², and power up to 70 mm². To exclude unauthorized access to the instrumentation, the terminal block has a cover with a locking device.
Measurements of protective potentials underground structures and control of the protective potentials of underground structures are carried out by connecting specialized devices to the Control and Measuring Point.
Instrument marking and warning (information) inscriptions are made on self-adhesive film using the thermal transfer printing method. In order to increase the resistance of markings and inscriptions to the effects of ultraviolet radiation on the racks and boxes of instrumentation, where the inscriptions are applied, external lamination of a special protective film. The durability of inscriptions and markings is at least 10 years.
The nomenclature of control and measuring points (CIP) is quite extensive and can be divided into types according to purpose and execution. However, this classification is conditional, because. depending on the specific conditions and design decisions, the purpose of a particular instrumentation may vary.
Racks can be made in versions for residential and non-residential areas, and differ in the installation method: for a non-residential area - above the ground, for a residential area - in the form of a carpet, flush with the ground or asphalt. There is also a type of instrumentation with telemetry, which, according to a given schedule, measure protective potentials and transmit data to the PC of the ECP service.
However, the main types of instrumentation are presented below:
1. Route, which is intended to measure the protective potentials of the pipeline in the direction of its passage. It is installed according to the project, along the pipeline route.
2. Instrumentation for anode fields, which is intended for connecting conductors from individual ground electrodes and connecting an anode cable from the KZU to them. Such instrumentation contains only power clamps on the terminal terminal. This design of the instrumentation makes it easy to create a connection and simplifies the diagnostics of individual ground electrodes during operation.
3. Instrumentation for drainage points, which are intended to connect the control and drainage conductors from the pipeline, as well as conductors from the reference electrodes to the corresponding conductors of the KZU. Such instruments contain power and control terminals on the terminal terminal.
4. Instrumentation with built-in BDR, which is intended for installation at the intersection of pipelines with other underground utilities for their joint protection. The control and measuring point with a built-in BDR allows joint protection of several metal structures and structures laid below ground level without the use of additional devices. Such instrumentation contains diode-resistor channels, power and control clamps on the terminal terminal.
TYPICAL TECHNOLOGICAL CHART (TTK)
INSTALLATION OF CONTROL AND MEASURING POINTS (CIP) DURING CONSTRUCTION
MEANS OF ELECTROCHEMICAL PROTECTION OF THE GAS PIPELINE
I. SCOPE
I. SCOPE
1.1. A typical technological map (hereinafter referred to as TTK) is a comprehensive regulatory document that establishes, according to a specific technology, the organization of work processes for the construction of a structure using the most modern means of mechanization, progressive designs and methods of performing work. They are designed for some average working conditions. The TTK is intended for use in the development of Projects for the production of works (PPR), other organizational and technological documentation, as well as for the purpose of familiarizing (training) workers and engineering and technical workers with the rules for performing work on the installation of control and measuring points (hereinafter referred to as instrumentation).
1.2. This map provides instructions on the organization and technology of work on the installation of control and measuring points, rational means of mechanization, data on quality control and acceptance of work, industrial safety and labor protection requirements in the production of work.
1.3. The regulatory framework for the development of technological maps are: SNiP, SN, SP, GESN-2001 ENiR, production norms for the consumption of materials, local progressive norms and prices, norms for labor costs, norms for the consumption of material and technical resources.
1.4. The purpose of the creation of the TC is to describe solutions for the organization and technology of the production of work on the installation of instrumentation in order to ensure their high quality, as well as:
- cost reduction of works;
- reduction of construction time;
- ensuring the safety of work performed;
- organization of rhythmic work;
- unification of technological solutions.
1.5. On the basis of the TTC, as part of the PPR (as mandatory components of the Work Execution Project), Working Flow Charts (RTC) are developed for the performance of certain types of work. Working technological maps are developed on the basis of standard maps for the specific conditions of a given construction organization, taking into account its design materials, natural conditions, the available fleet of machines and building materials, tied to local conditions. Working technological maps regulate the means of technological support and the rules for the implementation of technological processes in the production of work. Design features for the installation of instrumentation are decided in each case by the Working Design. The composition and level of detail of materials developed in the RTC are established by the relevant contracting construction organization, based on the specifics and scope of work performed. Working flow charts are reviewed and approved as part of the PPR by the head of the General Construction Contractor, in agreement with the Customer's organization, the Customer's Technical Supervision.
1.6. The technological map is intended for foremen, foremen and foremen who carry out work on the installation of instrumentation during the construction of electrochemical protection of the gas pipeline, as well as employees of the technical supervision of the Customer and is designed for specific conditions for the performance of work in the III temperature zone.
II. GENERAL PROVISIONS
2.1. The technological map was developed for a set of works on the installation of instrumentation.
2.2. Instrumentation installation work is carried out in one shift, the working hours during the shift are:
Where 0.828 is the coefficient of use of mechanisms in time during the shift (the time associated with preparing for work and conducting ETO - 15 minutes, breaks associated with the organization and technology of the production process and the driver's rest - 10 minutes every hour of work).
2.3. The technological map provides for the performance of work by a complex mechanized unit using the EO-2621 single-bucket excavator with a bucket capacity of 0.25 m (see Fig. 1).
Fig.1. Single-bucket excavator EO-2621
2.4. Instrumentation installation works include:
- geodetic breakdown of the location;
- digging a pit;
- connection of cathode and control leads to the pipeline;
- installation of reference electrodes;
- backfilling of the pit;
- installation of instrumentation;
- connection of cables, wires of the reference electrode.
2.5. The control and measuring point is a column made of a polymeric material having the shape of a trihedron, 2500 mm long with a mounting shield protected from dust and moisture. The number of instrumentation, their brand and location on the gas pipeline route are determined by the Working Design. With stationary instrumentation, current-measuring and marker points are combined.
2.6. Current-measuring checkpoints are installed on average after 5.0 km, as well as on both sides of the case when crossing the road and railway. The following are connected to the mounting shield of the current-measuring control point:
- cable from long-term reference electrodes;
- cable from electrochemical potential sensors (auxiliary electrode) and corrosion rate sensors;
- measuring cable from the pipeline (cathode lead);
- current-measuring cables welded to the gas pipeline at a distance of 30.0 m from the point.
2.7. Marker points are designed to link the data of planned in-pipe flaw detection, they are installed after 2.0-3.0 km along the gas pipeline route. Cables welded to the gas pipeline at the instrumentation installation site and directly to the marker pads installed in pairs 5.0 m from the instrumentation are connected to the mounting plate of such instrumentation.
2.8. Work should be carried out in accordance with the requirements of the following regulatory documents.
main gas pipelines and other facilities
"Gazprom"
Purpose
Control and measuring points RegionStroyZakaz (KIP.RSZ) for main gas pipelines and other facilities of OAO Gazprom, depending on the configuration, are designed to control and adjust the parameters of electrochemical protection (ECP) of underground utilities, switching individual elements of ECP systems, marking gas pipeline routes and other metal underground structures and cable communications. This type of product is personalized by applying the company logo and coloring the case and individual parts of the item in the colors corresponding to the internal regulations of OAO Gazprom. KIP.RSZ, on request, can be equipped with a high-altitude view roof (KVO) with kilometer or other marks.
KIP.RSZ are installed along the route of underground utilities:
on straight sections within sight, but not less than 500 - 1000 m (depending on the corrosion hazard of the underground utilities section);
in places where the route of underground utilities turns;
on both sides of the intersections of the underground communications route with artificial and natural barriers (roads, rivers, etc.);
in places where the drainage cable is connected to underground utilities;
in places of installation of insulating flange connections;
at the intersections with the routes of other above-ground and underground communications.
Description:
KIP.RSZ is a product based on a polymer profile of a round, trihedral or square section with face sizes from 130 to 200mm or diameters from 100 to 200mm, white, yellow, orange or other color. Inside the instrumentation there is a terminal panel with terminals made of non-ferrous metal or stainless steel for connecting power and measuring equipment. The terminal board is protected by a lockable cover to prevent free access. KIP.RSZ is equipped with an upper polymer cap-plug, the color of which may vary depending on the type of communications to be marked or other tasks. Reflective or fluorescent marks can be applied both to the sign itself and to the colored cap. At the bottom of the product there is a device that prevents the free removal of instrumentation from the ground.
The control panel is located at the top of the rack and is closed with a lid with a lock. Inside the control panel there is a terminal panel with power and measuring terminals for switching ECP facilities and connecting measuring equipment. terminals, contact clamps and measuring nests KIP.RSZ are made of non-ferrous metal or corrosion-resistant steel. The design of the clamps provides reliable electrical fastening of cables and wires without special termination of the cores:
for measuring clamps - with a section up to 10 mm2;
for power clamps - with a section up to 35 mm2.
Additional equipment for installation in KIP.RSZ
Additional equipment for KIP.RSZ
To expand the functionality of the instrumentation can be equipped with the following devices:
Joint Protection Unit(BSZ.RSZ) - designed to organize a joint electrochemicalprotection of two or more underground structures located in close proximity to each other (intersecting or parallel branches of underground utilities) and eliminating the harmful effects of neighboring utilities by regulating the protective current of the structure.
BSZ.RSZ can be supplied in various modifications that differ in the ways of regulating the protective current: resistor (BSZ-R.RSZ) and electronic (BSZ-E.RSZ) and the number of control channels from 1 to 4.
Block protective earth (BZZ.RSZ) - designed to protect underground structures from the corrosive effect of electromagnetic fields of power lines located near and / or crossing the protected structure, as well as to organize lightning protection.
BZZ.RSZ can be supplied in a modification for protection against the influence of power lines (BZZ-L.RSZ) and for lightning protection
(BZZ-G.RSZ).
Anode grounding control unit(BKAZ.RSZ) - designed for switching and monitoring the performance of anode earthing switches and electrical connections by including the block in electrical circuits anode grounding.
high-altitude view roof(KVO.RSZ) - designed to provide visual remote control of pipeline routes or communications from a height, during their inspection from the aircraft. Provides good visibility of signs with KVO, viewing and / or fixing serial numbers of kilometers or other information.
The high-altitude view roof is made of high-impact polystyrene in white, orange or red colors and is mechanically attached to the head of the identification warning sign or control and measuring point. In agreement with the customer upper part KVO using screen printing or stickers, kilometer marks or other information can be applied.