Technical re-equipment of the commercial metering unit in the enterprise EMG

1. General part

Basis for development of detailed documentation

Working documentation for technical re-equipment of the commercial gas metering unit in GRP on the territory of OJSC "????????????" at the address: Moscow,?????????? developed on the basis of the following materials:

Customer's terms of reference;

Moscow State Unitary Enterprise "Mosgaz" technical specifications;

and in accordance with the requirements of regulatory documents in force on the territory of the Russian Federation:

- 116FZ Federal Law "On Industrial Safety of Hazardous Production Facilities" dated 21.07.1997

- SP 62.13330.2011 "Gas distribution systems";

- PB1252903 "Safety rules for gas distribution and gas consumption systems";

- SP 421012003 "General provisions for the design and construction of gas distribution systems made of metal and polyethylene pipes";

- SP 421022004 "Design and construction of gas pipelines from metal pipes";

- PR50.2.01996 "Technique of performance of measurements by means of turbine, rotational and vortex counters".

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Purpose of technical re-equipment

The purpose of technical re-equipment is to bring the metering unit into compliance with the requirements of regulatory documents, increase reliability of operation and commercial accounting of gas consumption.

Characteristics of existing gas metering unit

The existing metering station represents the turbine SG161000 counter conditional pass of Du150 with the proofreader of EK88.

The design pressure of natural gas in the supply gas pipeline at the inlet to the FRG is Pp = 0.3 MPa (3 kgf/cm2). Gas filter GFS100 is installed on the supply gas pipeline.

The metering unit equipment shall be dismantled due to physical and moral wear and tear in accordance with the Customer's instructions.

Scope of technical rearmament

The working documentation includes the development of the internal gas supply section:

- Removal of gas metering unit equipment.

- Installation of commercial gas metering unit in FRG.

Key Technical Solutions

Gas is cleaned from mechanical impurities in FRG, gas pressure is reduced to the specified value, it is automatically kept constant, gas networks downstream the regulator are automatically protected from increasing or decreasing gas pressure beyond permissible limits in case of regulator malfunction, and gas flow rate is accounted for commercially.

The existing entry into the FRG room and the outlet of the gas pipeline have a nominal diameter Dn150, the pressure in the pipeline P = 0.3 MPa (3 kgf/cm3).

The designed Du150 pipelines in the GRP room are accepted from steel electric welded straight-joint pipes according to GOST 1070491 according to group "B" of steel grade St3sp according to GOST 1070580. Blowdown pipeline D20 is accepted from steel galvanized water and gas pipe as per GOST 326275, steel of grade St3sp as per GOST 3802005. Welding of gas pipelines shall be performed in accordance with the requirements of regulatory documents by electrodes of type E42A and E50A. Cover the gas pipelines with PF115 enamel in two layers according to the primer layer GF021, it is also necessary to apply identification paint in accordance with the requirements of GOST 1420269.

All GRP valves are accepted with the tightness of the class "A" gate according to GOST 954493 and have certificates and permission for use.

The gas pipelines are fixed on a support according to the typical series 5.90518.05 of SPKB Gazprom.

Installation and testing of gas pipelines should be carried out in accordance with the requirements of PB 1252903 "Safety Rules for Gas Distribution and Gas Consumption Systems," SP 62.13330.2011 "Gas Distribution Systems" and other regulatory documents.

The gas turbine meter SG161000 was used to account for the gas flow in the FRG. In view of technical and obsolescence of the counter and discrepancy of the existing gas metering with requirements of "Accounting rules of gas" and PR50.2.0192006 for commercial gas metering the complex for measurement of amount of SGEK gas is accepted.

In accordance with the calculation and analysis of the operation mode of the gas-using equipment given in the terms of reference for the re-equipment of the gas metering unit (see the appendix of this project), the SGEK measuring complex based on the TRZ G1000 meter with the following characteristics was adopted:

- a gas consumption - 50÷1600 of m3/hour.

- measuring range - 1:30;

At the same time, not all boiler equipment may be in operation, as confirmed by the letter of guarantee (see annexes to the documentation).

To bring the volume of natural gas passed through the gas meter to standard conditions, depending on the measured gas temperature and pressure and the calculated gas compressibility coefficient, the EC270 corrector is used in the EGEC complex.

For a detailed description of the composition of the EGPP complex and additional equipment, see the terms of reference for the re-equipment of the gas metering unit (appendix of this project).

The MCS complex, equipped with a differential pressure converter (PPD), also includes a set of straight sections (KPU) with pressure extraction points for the PPD, as well as a place for measuring temperature.

SGEK complex is resistant to dust and water with protection degree IP65 for corrector as per GOST 14254.

The requirement of the ECG complex based on the TRZ counter for a gas filtration degree of 0.08 mm by the existing D100 filter is not fulfilled. Existing filter with differential pressure gauge is replaced with FG16100 D100 filter. To monitor the change in pressure drop, the filter is supplied with the differential pressure indicator DPD16. The indicator does not have normalized metrological characteristics, is not a measuring tool, but allows to control the degree of clogging of the filter element. The FG16100 filter provides the required throughput and degree of filtration .

As additional devices for the metering unit, the power supply unit BPEK02/MT and the EPSON LX300 + printer are used. The BPEK02/MT power supply is intended:

for supply of explosion-proof devices with type of explosion protection "intrinsically safe electric circuit" with stabilized voltage;

to relay signals (lines) of the RS485 four-wire interface (full duplex) to the hazardous area;

for transmission of information from the gas metering complex of SGEK to the GSM network;

for connection of external communication devices.

A GSM modem is built into the power supply to transmit data from the metering node. The power supply has a built-in battery for backup power supply of the corrector and GSM modem in case of loss of mains voltage. The module of functional MP260 expansion for the organization of an additional communication channel for RS232 is a part of the BPEK02/MT power supply.

The existing gas pipeline and systems of the existing gas metering unit and filter shall be dismantled in accordance with the diagram (sheet 4). Blow and cut the dismantled gas pipeline.

Tie-in of the designed gas pipelines to the existing gas pipelines of EMG Du150 is carried out at a height of 1750 mm from the level of clean floor of EMG in accordance with the graphical appendix. Shut-off valves for gas metering unit shall also be replaced with "Broen Ballomax" Dou150 ball valves.

For gas pipeline blowdown, a blowdown line is provided with the installation of shutoff valves and a sampling nozzle. To visually monitor the gas pressure, a pressure gauge with a three-way crane is provided.

The designed purge line is connected to the existing purge line according to the graphical appendix.

Lightning protection and grounding

The existing EMG with discharge and blowdown candles is located in the lightning protection area. The gas pipeline and plugs are grounded according to PUE edition 7 dated 2004.

Grounding of the corrector housing and auxiliary switching equipment is performed in accordance with the requirements of GOST 21130.

Environmental protection

The working documentation does not provide for environmental protection measures, since the re-equipment of the commercial gas metering unit in the existing GRP of the enterprise does not adversely affect natural resources.

Safety and fire safety measures.

Enterprises operating gas-using equipment and pipelines shall be guided by the following requirements:

- License to operate a hazardous production facility. Admission to work of persons meeting the relevant qualification requirements.

- Provision of training and certification of employees in the field of industrial safety.

- Organization and implementation of industrial safety requirements by production personnel.

- Ensuring the functioning of the necessary instruments and control systems.

- Conclusion of a service contract with the professional rescue service.

- Planning and implementation of measures for localization and elimination of consequences of accidents.

- Training of employees in case of accident.

- Performance of works on extension of service life of technical devices according to the procedure established by Rostekhnadzor.

- Conclusion of a risk insurance contract for liability for causing harm during operation of a hazardous production facility.

- Prevention of unauthorized persons entering a dangerous production facility.

- Availability of reserve funds and material resources for localization and elimination of consequences of accidents.

- Taking part in the technical investigation of the causes of accidents, investigation of industrial accidents in accordance with the procedure established by the legislation of the Russian Federation and the regulatory documents of Rostekhnadzor of Russia.

- Keeping records of accidents, incidents, accidents at work, analysis of the causes of accidents, incidents, accidents, taking measures to prevent them and eliminate the causes.

Possible causes of the emergency:

- Leakage of natural gas from equipment, pipelines, shut-off devices.