Some standard content:
Chemical Industry Standard of the People's Republic of China
HG/T2437-93
Steel-plastic composite pipes and fittings
Published on June 14, 1993
Implemented on January 1, 1994
Published by the Ministry of Chemical Industry of the People's Republic of China
Steel-plastic composite pipes and fittings
HG/T2437-93
1 Subject content and scope of application
This standard specifies the product classification, technical requirements, test methods, inspection rules, marking, packaging, storage and transportation requirements of carbon steel pipe lined with thermoplastic plastics and steel-plastic composite pipes and fittings (hereinafter referred to as composite pipes and fittings). This standard applies to nominal pressure PN1.6MPa. Composite pipes and fittings with nominal diameter DN25~300mm lined with polyvinyl chloride and polypropylene, and composite pipes and fittings lined with other thermoplastics can be used for reference. 2 Reference standards
GB3092
GB 4216.3
GB4219
GB 5761
GB 8163
GB8923
GB 9119.8
GB12382.2
GB12670
GB/T13663
Product classification
Steel pressure vessels
Welded steel pipes for low-pressure fluid transportation
10 and 16 bar grey cast iron threaded pipe flange dimensions Hard polyvinyl fluoride pipes for chemical industry
Suspension method of vinyl chloride resin
Unbraided steel pipes for conveying fluids
Steel before painting Surface rust grade and rust removal grade PN1.0MPa (10bar) and 1.6MPa (16bar) convex neck threaded steel pipe flange PN1.6MPa (16uar) convex plate flat welded steel pipe flange PN2.0MPa (20bar) convex neck threaded spherical cast iron pipe flange defects Acrylic resin
High-density polyethylene pipes for water supply
3.1 Varieties
The varieties and codes of composite pipes and fittings are shown in Table 1. Table 1
Steel polyvinyl chloride composite pipe
Steel polypropylene tee
Steel polyvinyl chloride tee
Steel polypropylene four-way
Polyvinyl chloride four-way
Steel polypropylene 90* end
Steel polypropylene 45* end
Steel polyvinyl chloride 45* end
The Ministry of Chemical Industry of the People's Republic of China approved the generation of 1993-06-14
S/PP-G
S/PYC-G
S/PP-3T
S/PVC-3T
S/PP-4T
S/PVC-4T
S/PP-W(90)
S/ PP-W(45*)
S/PVC-W(90*)
S/PVC-W(45)
1994--01—01 implementation
Steel propylene reducing tee
Steel vinyl chloride reducing tee
Steel propylene concentric reducing pipe
Steel propylene eccentric reducing pipe
Steel vinyl chloride concentric reducing pipe
Steel vinyl chloride aligning reducing pipe
HG/T2437-93
Continued Table 1
S/ Pp-T(Y)
s/pVC-3T(Y)
S/PP-YG(T)
$ / PP-YG(P)
S/PVC-YG(T)
S / PVC-YG(P)
3.2 Specifications and basic parameters
3.2.1 See Figure 1 and Table 2 for the structure and basic dimensions of straight pipes.L
Nominal diameter DN
Inner diameter #
Length series L
Note: Users can negotiate with the manufacturer for special requirements.3.2.2 See Figure 2 and Table 3 for the structure and basic dimensions of tees.50
Nominal diameter DN
Inner diameter #
|2437-93
Dimensions from center to output surface L, H
For the structure and basic dimensions of the four, see Figure 3 and Table 4.3.2.3
Nominal diameter DN
Dimensions from center to butterfly surface, H
L, H Allowable end short
L, H Allowable tolerance
Minimum thickness of plastic inner wall 5
Minimum thickness of plastic inner wall
Nominal diameter DN
Inner diameter d
HG/T 2437--93
Continued Table 4
Center to end dimensions, good
The structure and basic dimensions of the 90 elbow are shown in Figure 4 and Table 5.s
Nominal diameter DN
Inner diameter 4
Center to end dimension
The structure and basic dimensions of the 45" elbow are shown in Figure 5 and Table 6.6
Nominal diameter DN
Center to end dimension
L, H allowable deviation
Allowable error
Allowable storage error||tt| |Minimum thickness of plastic inner tube S
Minimum overall thickness of plastic inner tube S
Minimum thickness of plastic inner tube S
Nominal diameter DN
HG/T2437-93
Continued Table 6
Center chamber surface size
32.6 The structure and basic dimensions of the reducing tee are shown in Figure 6 and Table 7.d.
Allowable deviation
Minimum overall thickness of plastic inner tube 5
Nominal diameter DN
40×40×25
50×50 x25
50 |tt||80 × 80 × 50
80×80×65
100×100×40
100×100×50
100×100×65
100 × 100× 80
125 125 x 65
125 × 125 × B0
125×125×100
150 × 150 × 65
150 × 150 × B0
1.50×150×100
150 ×200 × 100
200 × 200 × 125
200 200
300×300×125
300 × 300×150
300 × 300 × 200
300 × 300 × 250
Inner diameter of large end
2437--93
Inner diameter of small end4
Dimension from center to end face
Z, H allow
Concentric reducer.
The structure and basic design of eccentric reducer are as follows! Precision 8, cutting 8.
Minimum plastic reduction inner seal
Nominal diameter DN
40 × 25
50 × 25
50 × 32
50× 40
65×25
65 x 32
65×40
65 ×50
80×32
80×40| |tt||0× 50
80×65bzxz.net
100× 40
100 ×50
100×65
100×80||tt ||125 × 50
125 ×65
125×80
125×100
150×65
150×80
150×100
150×125
200 × 100
200 × 125
200 × 150
Big head inner diameter shrimp
243793
Small head inner diameter 4||tt ||Length L
L allowable deviation
Minimum wall thickness of plastics
Nominal diameter DN
250 × 100
250×125
250×150
250×200
300×125
300×150
300×200| |tt||300×250
Big head inner diameter 4,
243793
Continued Table B
Small purchase inner diameter 4,
L allowable deviation|| tt||Minimum thickness of plastic inner cavity S
32.8 Composite pipes and fittings should be made of GB 9119.8 or GH 9114.2, GB 4216.B, GE 123812, the size of the sealing surface of the profile is shown in Table 9. Table 9
Nominal diameter DN
4 Technical requirements
4.1 Material requirements
Minimum external dimensions of the plastic sealing surface Diameter
Minimum plastic sealing surface
4.1.1 Steel pipe
The performance of steel pipes used for composite pipes and pipe fittings shall comply with the relevant requirements of GB8163GB3092. 4.1.2 Plastic lining material|| tt||4.1.2.1 The performance of propylene used in composite pipes and fittings shall comply with the requirements of GB12670- and SG246. 4.1.2.2 The performance of vinyl chloride used in composite pipes and fittings shall comply with the requirements of GB4219 and GB5761. 4.1 Manufacturing requirements
4.2.1 Before plasticizing, the inner wall of steel pipes and fittings shall be free of burrs, rust and other debris, and the rust removal level shall comply with the requirements of S82 or ST2 in GB8923.
4.2,2 The welding of replacement parts shall be carried out in accordance with the relevant provisions of GB150. 4.2.3 When the welded pipe fittings are processed for the first time before plastic molding, a burst test shall be carried out, and the burst pressure shall not be less than the burst pressure value of the straight pipe calculated by the following formula:
Where: P--calculated bursting pressure of straight pipe, MPa; HG/T 2437-93
5-Minimum wall thickness of the tube (within the allowable deviation range), mD-Outer diameter of the tube, nm;
a-Tensile strength value of the material at room temperature, MPa.4.3 Finished product requirements
4.3.1 The inner and outer walls of composite pipes and fittings should be flat and smooth, without obvious unevenness, and the outer wall should be painted with anti-rust paint. 4.3.2 Plastic lining of composite pipes and fittings There should be no pinholes, cracks and impurities. 4.3.3 The length error of the combined pipe should not be greater than + mm. The size deviation of the pipe fittings should comply with the provisions of Table 3 to Table 8. 4.3.4 The straightness of the composite pipe should not be greater than 3 mm/m. (excluding pipe bending under its own weight). 4.3.5 The wall thickness of the plastic lining of composite pipes and fittings shall comply with Tables 2 to 8. 4.3.6 The plastic sealing surface of the composite pipe and the pipe fittings shall be free of defects, the processing pattern shall not be deeper than 10% of the wall thickness, and the sealing surface dimensions shall comply with the provisions of Table 9.
4.3.7 Face-to-face connection between composite pipe and pipe fittings The screw holes of the flange should be on the same center line, the adjustment disk should not be larger than ±1.6mm㎡, and the screw holes of the flanges on each end of the pipe fittings should be evenly distributed symmetrically on both sides of the horizontal and vertical center line, with an offset of no more than 1 /2. 4.3.8
The flange end faces of the composite pipe and pipe fittings should be perpendicular to the pipe centerline, and the verticality deviation should not exceed 2mm. 4.3.9||t t||Composite pipes and fittings shall be free of leakage and rupture after a 2.4 MPa water pressure test. 4.3.10
The vacuum values that composite pipes and fittings can withstand at room temperature are shown in Table 10. The vacuum values at other temperatures are provided by the manufacturer, Table 10
Plastic lining material
DN25--DN80
DN100~DN150
DN200DN300
DN25~DN80
DN100~DN150
DN200 ~DN300
The shear strength of the composite material lining layer shall meet the requirements of Table 11, 4.3.12
Plastic lining material
DN25~DNB0
DN100~DN150
DN200-DN300
DN25~ DN80
DNI00~DNI50
DN200 ~ DN300
The maximum service temperature that composite pipes and fittings can withstand is shown in Table 12.4.3,13
Plastic lining materials
4.3.14The minimum service temperature that composite pipes and fittings can withstand Temperature see Table 13. Vacuum value (kPa)
Shear force (MPa)
Maximum operating temperature
+107±3
+65±3| |tt||Plastic lining material
2437-93
Minimum operating temperature
-18± 2
4.3.15 After the high and low temperature cycle test specified in Table 14, the composite pipes and pipe fittings should not have cracks, deformation or other phenomena that affect their use.
Plastic inner tree material|| tt||Test method
Appearance inspection
Commodity temperature
+100±3
+60 ±3
County test, use if necessary Inner wall periscope inspection, 5.2 Dimension inspection
Use measuring tools with required accuracy or tooling with load accuracy for inspection. Plastic lining pinhole and crack inspection
Low temperature
+25 ± 2
+25 ± 2
Cyclic excitation
Use 5～ 20kV true current spark detector test, the test voltage is 10kV, the probe should contact the plastic lining layer and move at a speed of about 100mm/s. If no spark appears or alarm sound is heard during movement, it is considered The pinhole and crack inspection of the plastic inner layer is qualified.
5.4 Positive pressure test
5.4.1 Equipment and instruments
Hydraulic testing machine: 0~6.0MPa
Pressure gauge:
5.4.2 Test Method
Precision should not be less than 1.5 level
The test should be carried out under ambient conditions. Connect the composite pipe and pipe fittings with flanges on the flow press, connect the pressure source, apply pressure, m Make the internal pressure reach 2.4MPa, maintain the pressure for 5 minutes, and check whether the composite pipe or pipe fittings have leakage. If there is no leakage, the positive pressure test is deemed to be qualified.
5.5 Vacuum test
3.5.1 Equipment and instruments
Vacuum pump, vacuum pressure gauge
5.5.2 Test specimen
Pipe fittings or composite pipes with a length not less than 10 times the pipe diameter. 5.5.3 Test method
Connect one end of the sample to the vacuum pump and the other end to the flange of the sight glass. Start the vacuum pump to evacuate the sample. The vacuum value should be reached within two minutes and maintained. After 48 hours, if there are no wrinkles or cracks in the plastic lining, the vacuum test is deemed to be qualified. 5.6 Shear test of plastic lining
5.6.1 Test temperature
5.6.2 Test equipment||tt ||Material testing machine: 0~150N, measuring accuracy not less than Class 1. 5.6.3 Test specimens
HG/T 2437-93
Three pieces are taken for each test specimen, the same The sample group should be cut from the head, tail and middle of a composite pipe. The sample length is 150m. Both end surfaces should be flush.
5.6.4 Test method
Use a vernier caliper to accurately measure the length of the specimen and the diameter D of the steel-plastic contact surface. Adjust the speed of the testing machine to 20±5 mm/min. Clamp the pressure head and the support die that match the specimen on the testing machine. Apply pressure as shown in Figure 9 and record the load value when the composite plastic liner is peeled off.
1-Presser:
5.6.5 Processing of test data
Calculate the shear strength according to the following formula, with an accuracy of 0.01 MPa, where: α-shear strength, MPa;
F-peeling pressure of plastic liner, N;
D-diameter of the steel-plastic contact surface of the specimen, mm;
L-length of the specimen, mm.
2-composite material;
The test results are expressed as the arithmetic mean of the measured values of each group of specimens. 3
3.7 High temperature resistance test
Put the pipe fittings or composite pipes with a length of not less than 1000mm into a high temperature test box, and then gradually increase the temperature in the box to the maximum use temperature specified in Table 12. After keeping warm for 3 hours, take it out for air cooling. After cooling, the temperature of the plastic lining does not exceed 29 degrees Celsius. Repeat this process three times, and check whether the plastic lining has deformation or cracks. If there is no deformation or cracks, the high temperature test is considered to be qualified. 5.8 Low temperature resistance test
Put the pipe fittings or composite pipes with a length of not less than 1000mm into a low temperature test box, and then gradually reduce the temperature in the box to the minimum use temperature specified in Table 13. After keeping warm for 3 hours, take it out for air cooling. Repeat this process three times, and check whether the plastic lining has deformation or cracks. If there is no deformation or cracks, the low temperature resistance test is considered to be qualified. 5.9 High and low temperature cycle test
5.9.1 The pipe fittings or composite pipes with a length of not less than 3006m shall be subjected to a low temperature cycle test to determine whether the plastic lining layer can withstand the working medium + 11.
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