Installation of a block gas boiler house in the village of Zonikha, Sloboda district, Kirov region

General Instructions

This project was carried out on the basis of the assignment for the design of the KOGU "Directorate for Gasification and Engineering Infrastructure" of Kirov.

The detailed drawings are in accordance with applicable codes, regulations and standards.

The design provides for underground laying of the gas pipeline from the tie-in point to the previously designed underground polyethylene gas pipeline PE80 GAZ SDR11160x14.6, Ru 0.289 MPa to the block gas boiler of the factory supply. Connection is made by means of seat branch Ø160/63 (refer to L.6I1). A polyethylene crane manufactured by Frialen is installed at the tie-in point. The rod of the underground crane is removed under a carpet (see l. 3I1). Around a cover the protection is provided by the sizes of 3.7х3.5х1.7 m (H) (see l. 4I1). The designed medium pressure gas pipeline is laid from PE 80 GAZ SDR1190x8.2 polyethylene pipes. At the exit from the ground in front of the boiler room, the gas pipeline is made of 89x4.0 steel electric welded straight-joint pipes, according to GOST 1070491 of steel Vs3sp as per GOST 3802005 and a valve Ø80 with an insulating connection SI80s is installed.

The polyethylene-steel connection is located on a horizontal section, which is laid on the base of sand (except for dust) with a length of 1 m each side of the connection, with a height of at least 10 cm and sprinkled with a layer of sand to a height of at least 20 cm.

All devices required for boiler operation, as well as devices for measuring, controlling, switching on boilers and ensuring their safe operation are included in the scope of supply.

Boiler room capacity 2.5 MW (2.15 Gcal/h). Gas flow rate at Qp n = 8000 kcal/nm 3 is 268.75 nm3/h.

Designation of underground gas pipeline route shall be performed by installation of identification marks.

The route of the underground polyethylene gas pipeline is indicated by laying along the entire length of the route a yellow signal tape with a width of at least 0.2m with the indelible inscription "Flammable - gas" at a distance of at least 0.2 m from the upper generatrix of the gas pipeline.

The above-ground gas pipeline is protected against corrosion by paint coating with identification painting as per GOST 1420269.

Underground medium pressure polyethylene gas pipeline shall be tested for tightness with pressure P = 0.6 MPa within 24 hours.

Aboveground medium pressure gas pipeline - P = 0.45 MPa for 1 hour.

Butt joints of steel gas pipelines shall be controlled by physical methods in the following volumes (but not less than one joint) of the total number of joints welded by each welder at the facility:

aboveground high-pressure medium-pressure gas pipeline - 5%;

Butt joints of polyethylene gas pipelines welded with the help of welding technique of high degree of automation shall be checked by ultrasonic inspection in the following volumes (but not less than one joint) of the total number of joints welded by each welder at the facility:

low-pressure gas pipeline - 3%;

medium pressure gas pipeline - 12%.

Fill the holes between the case and the gas pipeline with elastic moisture-resistant material (ground and bitumen mastic), and the holes outside the case with high-grade cement or concrete mortar.

Installation, test, acceptance for operation of the gas pipeline of a message according to PB 1252903 "Safety rules of systems of gas distribution and gas consumption", Construction Norms and Regulations 42012002 "Gas-distributing systems", the joint venture 421012003 "General provisions on design and construction of gas-distributing systems from metal and polyethylene pipes", the joint venture 421012003 "Design and constructions of gas pipelines from metal pipes", the joint venture 421032003 "Design and construction of gas pipelines from polyethylene pipes and reconstruction of worn-out gas pipelines".

List of types of works, for which it is necessary to draw up certificates of inspection of hidden works:

- for geodetic breakdown of the route;

- for arrangement of trench;

- for preparation of the base for the gas pipeline;

- for welding of guarantee joint and quality check of welded joints;

- to check the position of the gas pipeline pipe in plan and height;

- for insulation of joints and protective coating of gas pipeline pipe;

- for strength test, gas pipeline tightness test;

- for acceptance of gas pipeline electrochemical protection;

- for backfilling of gas pipeline with sealing.