Gas supply to the microdistrict in the private sector

1. Common part.

The project "Gas supply of the microdistrict in the amount of 277 sections along Tyumenyakskaya St., Tyumenyaksky St., Frudovaya St., S. Kirsanova St., Novoselskaya St., Uzornaya St., Gornaya St., S. Dadaya St., Mayskaya St., Kalinovaya St. in Turn 2.03manovo, Tuymazinsky Street ymazinsky Street iya, Mayl., Mayskaya Street 1, Mayskaya, 12M12Mayskid, 12May., Technical ayon the basis of Technical 1.0SYY2. issued by JSC Gazservice.

The project has been completed in accordance with the requirements of the following regulatory documents:

- SP 62.13330.2011 "Gas Distribution Systems" (Updated Revision

SNiP 42012002)

- "Technical Regulations on Safety of Gas Distribution and Gas Consumption Networks"

- SP 48.13330.2011 "Construction Organization"

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

-GOST 9.6022005 "Unified Corrosion and Aging Protection System. Underground structures. General requirements for corrosion protection. "

-SNiP 3.02.0187 * "Earthworks, foundations and foundations."

Area and construction area data:

- the construction site of the pipeline route belongs to 1 "B" climatic subdistrict with the design winter temperature of external air minus 35 wasps.

- freezing depth 1.8m

- prevailing winds - south and south-west.

According to engineering and geological surveys, the base for gas pipelines will be refractory loams and semi-solid clay. Soils do not have subsidence, swelling properties and are weakly pubescent. Engineering-geological researches are executed by LLC UralSibIzyskaniya Ufa in 2009 by request of No. 212009/WUXI.

The main material for the project implementation was: topographic survey performed by LLC Geodesia Service in 2011.

The scheme of high and low pressure gas distribution is developed based on the location, structure and density of Raimanovo, as well as the location of gas supply sources.

According to specifications this project provided insert in the existing underground polyethylene gas pipeline of high pressure Ø225h20.5mm.

The project provides for:

1. The high-pressure gas pipeline of category II Rr≤0,6MPa from the tie-in point to the designed PGB-15-2HU1.

2. PGB152NU1 installation (RDG80N regulators) with the main and reserve line of reduction, with gas heating. (VTO "VOLGAGAZ" Saratov)

3. The gas distribution pipeline low pressure I from the projected PGB152NU1 to houses in the residential district under construction of the village of Raymanovo.

4. Low-pressure gas pipeline from t. Cut No. 2 to the designed low-pressure gas pipeline with the conversion of the gas pipeline-inlet to a residential building in the village. Raimanovo, st. School No. 31a

Fuel - natural gas, total gas flow rate - 706.34 nm3/h.

1.1 Hydraulic calculation of high pressure gas pipeline

Hydraulic calculation of high pressure is performed according to the procedure given in SP 42 101-2003 item 3.27 for maximum gas flow rate.

The calculation was made taking into account loads by consumers of the new microdistrict of Raymanov village.

According to the specification, the total flow rate is 706.34 m3/h. The total load of consumers and the pressure at the tie-in point (Rr≤0,6MPa) in the main gas pipeline of high pressure are accepted in accordance with the technical specifications of GazService OJSC. The pressure at the inlet to the PGB at the diameter of the pipeline Ø110x10.0 mm was - 0.59MPa.

1.2 Hydraulic calculation of low pressure gas pipeline

The total load of consumers is accepted according to the specifications of JSC "GazService" 706.34 m3/h .

The estimated gas flow rate in the low pressure distribution external gas pipelines sections having gas flow rates is defined as the sum of the transit and 0.5 gas flow rates in this section.

The diameters of the gas pipeline are determined by hydraulic calculation based on the condition of normal and economical gas supply by all categories of consumers during the hours of maximum gas consumption at maximum permissible pressure drops.

The diameters of the low pressure gas pipeline are calculated according to the nomogram for calculating the low pressure gas pipeline .

Pressure losses at the design section of the gas pipeline are determined by nomogram depending on the accepted diameter of the gas pipeline and the load at the design section of the gas pipeline.

Knowing the gas flow rate at each section of the gas pipeline, the length of the section, diameter, by nomogram

find the ∆R and then the final gas pressure at each site.

The calculation data of the low pressure gas pipeline are given in diagram No. 1 (see sheet 16PZ).

2. Process Part

2.1. High gas distribution pipelines (P r≤ 1.2 MPa)

and low (Pp ≤ 0.003 MPa) pressure

According to TU, the place of tie-in1 is accepted into the existing high-pressure polyethylene gas pipeline Ø225 mm in underground design at elevation h = -1.2 m from ground level .

To reduce the gas pressure from high to low and maintain it at a given level, PGB152HU1 is provided with two reduction lines (main and standby), with RDG80N regulators, with gas heating. The grade of the pressure regulator is adopted in accordance with technical conditions taking into account the prospects for the development of the microdistrict and the subsequent loopback of the designed gas pipeline.

PGB-50 shall be installed at a distance of not less than 1.5 heights of power transmission line supports from power transmission line wires, not less than 10.0 m from buildings and structures and not less than 5.0 m from roads.

At the inlet and outlet of gas pipelines PGB152NU1 install IFS Du80mm with visor and at a distance of 5.0m from PGB install steel gate valves of 30s41ng grade .

To provide an installation site of PGB152NU1 in a steel mesh protection 10.7x9.8x1.6 (h) m with the gate device.

From PGB152NU1 to bring blowing-off and waste candles to height not less than 4.0 m from ground level.

The designed high-pressure gas pipeline from the tie-in point to PGB152HU1 should be laid underground at a depth of at least 1.0m to the top of the pipe. The gas pipeline of high pressure is designed from polyethylene pipes PE 100 GAZ SDR 11 - 110kh10,0mm in accordance with GOST P5083895*. Safety factor of polyethylene pipes of high pressure gas pipeline is not less than 3.2. Individual sections of the gas pipeline are designed from steel electric welded pipes according to GOST 1070491, pipe material - steel, grade 10, group B according to GOST 1070580, laid above ground and underground.

The designed low-pressure gas pipeline should be laid underground at a depth of 0.9-1.0m to the top of the pipe, the section of the low-pressure gas pipeline laid at the intersection with the existing high-pressure gas pipeline - at a depth of 1.5 m to the top of the pipe.

Low pressure gas pipeline (R≤0,003) MPa is designed from polyethylene pipes PE 80 GAZ SDR 17.6 - 315x17.9mm, 225x12.8mm, 160x9.1mm, 110x6.3mm; 63kh3,6mm PE 80 GAZ SDR 17.6 in accordance with GOST P5083895*. Safety factor of polyethylene pipes of low pressure gas pipeline is not less than 2.6. Individual sections of the gas pipeline are designed from steel electric welded pipes according to GOST 1070491, pipe material - steel, grade 10, group B according to GOST 1070580, laid above ground and underground.

According to the specification, the place of tie-in 2 is accepted into the existing low-pressure steel gas pipeline Ø102 mm in underground design at the elevation h = -1.2 m from ground level.

The low-pressure gas pipeline from cut No. 2 to the designed gas pipeline shall be made of 110x6.3mm PE 80 GAZ SDR 17.6 polyethylene pipes as per GOST R5083895 *.

Along Shkolnaya St. near the section of residential building No. 48 on the low-pressure gas pipeline there is an installation of a disconnecting device, D100mm 30s41ng gate valves in the above-ground version, in a steel mesh fence 2.4x1.4x1.6 (h) m with a gate device. When crossing the designed low-pressure gas pipeline with the existing high-pressure gas pipeline, the distance in the light is not less than 0.2 m. At parallel

laying from fencing foundations and 6 kV VL supports to the designed gas pipeline - not less than 5.0 m, from 0.4 kV VL supports to the designed gas pipeline - not less than 1.0 m,

Passive protection of the underground steel gas pipeline of high and low pressure shall be made "very reinforced" according to GOST 9.602 with insulation film "Polylen 40LI45" in 4 layer by glue "Primer NK50."

Protect the above-ground gas pipeline of high and low pressure from atmospheric corrosion with paint coatings in 2 times according to GOST 1420269 with KhV124 enamel of light tones (yellow).

Connections of polyethylene gas pipelines with steel are provided as non-detachable in the soil, in horizontal sections. Put the "polyethylene steel" permanent joint on the sand base with a length of 1 m to each side of the joint, with a height of not less than 10 cm and sprinkle with a layer of sand to a height of not less than 20 cm.

Polyethylene pipes are connected to each other by welding using couplings with embedded heaters. Welding of polyethylene pipes using couplings with embedded heaters shall be performed at ambient temperature not higher than + 35 ° С and not lower than 50 ° С. The welding site is protected from moisture, sand, dust, etc.

Welding with the help of couplings with embedded heaters consists in melting of polyethylene on the connected surfaces of the coupling and pipes due to heat generated during flow of electric current through electric spirals embedded in the coupling, and subsequent natural cooling of the connection.

If the ends of the pipes to be welded have an increased ovality (more than 1.5% of de), inventory calibration clamps are used before the joint is assembled to give them a cylindrical shape, which are installed on the pipes at a distance of 1530 mm from the marks.

To avoid damage to embedded heaters (wire spirals), the coupling is put on the end of the pipe or the end of the pipe is inserted into the coupling with caution without distortion and, turning, without great effort.

The transition of polyethylene pipes from one diameter to another should be carried out using connecting parts made of polyethylene (tees, transitions), Specification 61935287. Turns of the linear part of the polyethylene gas pipeline in horizontal and vertical planes shall be performed using cast taps made of polyethylene of factory manufacture.

When laying the polyethylene gas pipeline at distance of 0.2 m from pipeline top, the polyethylene alarm tape of the yellow color not less than 0.2 m wide with an indelible inscription of OgneopasnoGaz (TU224502800203536) on all length of the route keeps within.

At the intersection of the low-pressure gas pipeline with the existing high-pressure gas pipeline, the signal belt must be laid along the gas pipeline twice at a distance of at least 0.2 between each other and at 2, 0 m to both sides of the crossed gas pipeline. The designation of the gas pipeline route is provided: by installing identification marks (at the angles of rotation, at places of diameter change, installation of valves and structures belonging to the gas pipeline, at the locations of non-detachable joints "polyethylene steel," as well as in rectilinear sections after 200 m). The indicators should be located at a distance of 1 m from the axis of the gas pipeline, to the right along the gas flow.

The total length of the high pressure gas pipeline was 31.0 m, taking into account the stock of polyethylene pipes in the amount of 2% of the total length of the gas pipeline, intended for laying pipes with a snake, conducting incoming quality control of pipe material, welding of tolerance joints, as well as emergency reserve used to eliminate damage to polyethylene pipes that may occur during operation.

The total length of the low pressure gas pipeline was 7320.5 m, taking into account the stock of polyethylene pipes in the amount of 2% of the total length of the gas pipeline.

2.2. Gas Control Point

The design provides for installation of a full-assembly gas control station of the grade PGB152HU1 with the main and standby reduction lines and one output line, with regulators

RDG-80N, with gas heating.

The gas control station PGB152NU1 is manufactured in accordance with the requirements of the "Safety Rules for Gas Distribution and Gas Consumption Systems" PB 12529 and has a conclusion on technical safety, Rostekhnadzor permission for production and use, the equipment has a quality certificate.

The PGB is a metal insulated box mounted on the base.

Natural, permanent ventilation is provided in the PGB room, providing at least three times air exchange per 1 hour.

PGB-15-2HU1 is designed to reduce the high pressure to the required one, automatically maintain the specified output pressure at the specified level, regardless of changes in flow rate and input pressure, automatically disconnect the gas supply at emergency increase and decrease of output pressure above permissible values, clean the gas from mechanical impurities.

Gas control station PGB-15-2HU1

technical data

Maximum inlet gas pressure, MPa 1,2

Gas capacity at pressure

at input Pp = 1.2MPa, nm3/h 14600

Output pressure, kPa 1.5-60

Regulator RDG80N, pcs. 2

Overall dimensions, height/length/width, mm 2440/3320/1900

Weight, kg 3000

2.3. Electric lighting. Lightning protection and grounding

SGS rooms shall have natural and artificial lighting. PGB power supply is provided from the existing BJI0.4 kV network by construction of the cable line ABBbShv with a section of 3x16 mm.

Perform power supply installation works in accordance with the requirements of PUE, SNiP 3.05.0685, SNiP 120399.

On PGB152NU1, blowing-off, waste candles and the elevated gas pipeline to provide lightning protection with a grounding contour according to requirements of CO153.34.21.1222003 "Instruction for design and the structure of lightning protection of buildings and constructions" and Construction Norms and Regulations 3.05.0685 "Electrotechnical devices".

3. Construction part.

Foundation for PGB152NU1: Cast-in-situ concrete B15 brand 200. For cast-in-situ foundation prepare from concrete B10, 100mm thick.

Before the foundation is completed, provide a base of sand and gravel mixture with a grain fraction of 335mm to a depth of 1.8m from ground level. Corrosion protection of the surface of steel structures of fences, supports, brackets shall be performed in accordance with SNiP 2.02.1185.

The foundation for metal supports shall be made of M150 concrete to a depth of 1,98m.

4. Control over the construction of gas pipelines.

External inspection and measurements

External inspection and measurements check:

- depth of underground (ground) or above-ground gas pipeline, slopes, structure of base, bed or supports, length, diameter and thickness of pipeline walls; installation of shut-off valves and other gas pipeline elements. Measurements are performed as per GOST 26433.2;

- type, dimensions and presence of defects on each of welded butt joints of pipelines;

continuity, adhesion to steel and thickness of protective coatings of pipes and connections 10.2.2. Check of underground pipelines (tanks) is performed before and after their lowering into a trench (pit). Defects detected by external inspection and measurements are eliminated. Unacceptable defects in welded butt joints shall be removed.

Mechanical tests.

Mechanical tests shall be performed by:

test (tolerance) joints performed during qualification tests of welders and verification of welding technology of joints of steel and polyethylene gas pipelines;

welded joints of steel gas pipelines, which are not subject to physical control, and joints of underground gas pipelines welded by gas welding .

Joints of steel gas pipelines are tested for static tension and for bending or flattening according to GOST 6996 .

Mechanical properties of joints of steel pipes with nominal diameter over 50 mm are determined by tensile and bending tests (cut uniformly along the perimeter of each selected joint) of samples with removed reinforcement in accordance with GOST 6996.

The results of mechanical tests of the joint are considered unsatisfactory, if;

arithmetic mean tensile strength of three samples in a tensile test less than the standard tensile strength of the pipe base metal;

The arithmetic mean bending angle of the three samples for bending tests less than 120 ° for arc welding and less than 100 ° for gas welding;

test result of at least one of three samples for one of the types of tests is 10% lower than the standard value of strength or bending angle.

Mechanical properties of welded joints of steel pipes with a nominal diameter of up to and including 50 mm shall be determined by tests of whole joints for tension and flattening. For pipes of these diameters, half of the joints selected for control (with unoccupied reinforcement) should be tested for tension and half (with removed reinforcement) for flattening.

The results of mechanical tests of the weld joint are considered unsatisfactory if:

tensile joint test strength less than the standard tensile strength of the pipe base metal;

clearance between pressing surfaces of the press at occurrence of the first crack on the weld joint during the joint flattening test exceeds the value 5S, where S- is the nominal thickness of the pipe wall.

In case of unsatisfactory tests of at least one joint, repeated tests of twice the number of joints are carried out. The inspection shall be carried out according to the type of tests, which gave unsatisfactory results.

If unsatisfactory test results are obtained at least at one joint during the re-inspection, all joints welded by this welder during the calendar month at this object by gas welding shall be removed, and joints welded by arc welding shall be checked by radiographic inspection method.