GB/T 21238-2016Glass fiber reinforced plastics mortar pipes (English PDF)

4.1 Classification

4.1.1 FRPM tubes are classified according to process, nominal diameter, pressure rating and ring stiffness rating.

4.1.2 Process method. I---fixed length winding process; II---centrifugal casting process; III---continuous winding process.

4.1.3 The nominal diameter DN is shown in Tables 1 and 2.

4.1.4 Pressure rating PN. 0.1MPa, 0.25MPa, 0.4MPa, 0.6MPa, 0.8MPa, 1.0MPa, 1.2MPa, 1.4MPa,

1.6 MPa, 2.0 MPa, 2.5 MPa, 3.2 MPa.

4.1.5 Ring stiffness grade SN. 1250N/m2, 2500N/m2, 5000N/m2, 7500N/m2, 10000N/m2.

4.2 Marking

The marking method of the FRPM tube is as follows.

FRPM

product code

Production Process

Nominal diameter

Pressure Level

Ring stiffness rating Example. The nominal diameter is 1200mm, the pressure rating is 0.6MPa, and the ring stiffness rating is 5000N/m2, which is produced according to this standard.

The FRPM tubes produced are marked as.

5.1 Reinforcement materials

FRPM tubes should be made from alkali-free glass fibers and their products. The alkali-free and untwisted glass fiber yarn used should conform to GB/T 18369 Provisions. E-glass fiber products shall comply with the relevant national or industry standards.

Note. Where specific media needs to be transported, other reinforcing materials with performance requirements may be used after agreement between the supplier and the purchaser.

5.2 Resin

5.2.1 The unsaturated polyester resin used should meet the requirements of GB/T 8237. Other resins should comply with the corresponding national or industry standards Provisions.

5.2.2 The inner liner resin shall be made of isophthalic unsaturated polyester resin, bisphenol A unsaturated polyester resin or vinyl ester resin.

5.2.3 The sanitary index of the inner liner resin of FRPM pipe for water supply engineering shall meet the requirements of GB 13115.

5.2.4 See Appendix A for the performance requirements of resin castings.

5.3 Filler

The maximum particle size of the filler does not permit a smaller value between greater than 2.5 mm and one-fifth of the wall thickness. Among them, quartz sand contains SiO2 the amount should be greater than 95%, the water content should be no more than 0.2%; the CaCO3 content of calcium carbonate should be greater than 98%, and the water content should be no more than 0.2%.

6.1 Appearance quality

The inner surface of the FRPM tube should be smooth and flat, without cracks, delamination, pinholes, impurities, gel-in areas, bubbles and fibers that have an impact on performance.

Dimensional infiltration and other phenomena; the end of the tube should be flush; the edges should be free of burrs; the outer surface has no obvious defects.

6.2 Size

6.2.1 Diameter

The outer diameter series shall comply with the requirements of Table 1, and the inner diameter series shall comply with the requirements of Table 2. In order to facilitate the connection with other material pipes, supply and demand the two sides negotiated to determine the size of other material pipes and meet the corresponding requirements.

6.2.2 Length

6.2.2.1 The effective length of the FRPM pipe is 3m, 4m, 5m, 6m, 9m, 10m, 12m, 18m. If you need a special length of tube, it is agreed upon by the supplier and the buyer at the time of delivery.

6.2.2.2 Length deviation of FRPM tube. ±0.5% of effective length and not exceeding ±60mm.

6.2.3 Wall thickness

The average wall thickness of any section shall not be less than the design thickness, and the minimum wall thickness shall not be less than 90% of the design thickness. When the pipe wall is set when the thickness is not more than 20mm, the average wall thickness shall not exceed 1.15t; when the design thickness of the pipe wall is greater than 20mm, the average thickness of the pipe wall should not be greater than (t 3) mm.

Note. t is the design thickness of the pipe wall, determined by the pipe manufacturer through design, and given in the technical documents.

Table 1 Dimensions and deviations of the outer diameter series FRPM tube are in millimeters

Nominal diameter DN outer diameter deviation 1.0,-1.0 1.0,-1.0 1.0,-1.0 1.0,-1.2 1.0,-1.4 1.0,-1.6 1.0,-1.8 1.0,-2.0 1.0,-2.2 1.0,-2.4 1.0,-2.6 2.0,-2.6 2.0,-2.6 2.0,-2.8 2.0,-2.8

Table 1 (continued) Unit is mm

Nominal diameter DN outer diameter deviation 2.0,-3.0 2.0,-3.0 2.0,-3.2 2.0, -3.4 2.0, -3.6 2.0,-3.8 2.0,-4.0 2.0,-4.2 2.0, -4.4 2.0,-4.6 2.0,-4.8 2.0,-5.0 Other outer diameter series sizes can be used according to actual conditions, but the outer diameter deviation should meet the corresponding requirements.

Table 2 Dimensions and deviations of the inner diameter series FRPM tube are in millimeters

Nominal diameter DN

Inner diameter range of both ends Minimum Maximum deviation ±1.5 ±1.5 ±1.5 ±1.5 ±1.5 ±1.8 ±2.1 ±2.4 ±2.7 ±3.0 ±3.6 ±4.2 ±4.2 ±4.2 ±4.2 ±5.0

Table 2 (continued) Unit is mm

Nominal diameter DN

Inner diameter range of both ends Minimum Maximum deviation ±5.0 ±5.0 ±5.0 ±5.0 ±5.0 ±6.0 ±6.0 ±6.0 ±6.0 ±6.0 ±6.0 ±6.0 ±7.0 ±7.0 for taper tube designs, the design values shall be within the inner diameters of the ends specified in this table. The actual value of the inner diameter of the two ends of the pipe may be different.

The provisions of the full table.

6.2.4 Inner liner thickness

It should be no less than 1.2mm.

6.2.5 Tube end face verticality

It should meet the requirements of Table 3.

Table 3 Tube end face verticality requirements in millimeters

Nominal diameter DN tube end face vertical deviation DN< 600 4 600<=DN< 1000 6 DN>=1000 8

6.3 Barcol hardness

The Bakr hardness of the outer surface of the FRPM tube should be not less than 40.

6.4 Resin insoluble content

The insoluble content of the resin in the pipe wall should be not less than 90%.

6.5 Direct pipe section wall component mass percentage

The content of glass fiber, resin and filler in the pipe wall of the straight pipe section is determined by the pipe design and shall be clearly stated in the technical documents. Components the mass percentage tolerance is ±3.

6.6 Initial mechanical properties

6.6.1 Initial ring stiffness S0

The initial ring stiffness S0 should not be less than the corresponding ring stiffness class value SN.

6.6.2 Initial hoop tensile strength Fth

The initial hoop tensile strength Fth of the pipe wall shall be determined according to the engineering design, but the minimum value is determined according to formula (1).

Fth=C1·PN·DN/2 (1)

In the formula.

Fth---initial hoop tensile strength in units of kilonewtons per meter (kN/m);

C1---Initial hoop tensile strength safety factor, see Table 4; when no pressure design basis PDB test results, take C1=6.3;

The minimum value of the initial hoop tensile strength at C1=6.3 is shown in Table 5;

PN---pressure rating in MPa (MPa);

DN---Nominal diameter in millimeters (mm).

Table 4 Initial hoop tensile strength safety factor C1

Pressure rating PN

MPa

1.5 1.75 2.0 2.5 3.0 0.1 0.25 0.4 0.6 0.8 1.0 1.2 1.4 1.6 2.0 2.5 3.2 4.2 4.2 4.1 5.3 5.3 5.1 5.0 4.9 4.8 4.7 4.6 4.5 4.3 6.3 6.3 6.2 6.0 5.9 5.7 5.6 5.5 5.4 5.1 4.8 4.5 alpha=P0/PDB; where. P0 is the short-time failure water pressure; PDB is the pressure design basis.

When the coefficient of dispersion of the initial hoop tensile strength of the tube is CV >9.0%, C1 should be taken as the table median multiplied by 0.8236/(1-1.96 CV).

Table 5 The minimum value of the initial hoop tensile strength without PDB is Fth. The unit is kilograms per meter.

Nominal diameter DN

Pressure Level

MPa

0.1 0.25 0.4 0.6 0.8 1.0 1.2 1.4 1.6 2.0 2.5 3.2

6.6.3 Initial axial tensile strength and tensile strain at break

The initial axial tensile strength and tensile strain at break are determined according to whether the pipe produces axial force.

a) Initial axial tensile strength of the pipe wall when the pipe is not subjected to axial forces directly generated by the pipe internal pressure or is not subjected to special axial forces FtL shall not be less than the value specified in Table 6; the axial tensile fracture strain of the pipe wall shall be not less than 0.25%.

Table 6 Initial axial tensile strength minimum FtL Unit is kilograms per meter

Nominal diameter DN

Pressure Level

MPa

<=0.4 0.6 0.8 1.0 1.2 1.4 1.6 2.0 2.5 3.2

b) When the pipeline is subjected to the axial force generated by the internal pressure of the pipe, the initial axial tensile strength FtL of the pipe wall shall satisfy the requirements of formula (2). tube the axial tensile strain at wall is not less than 0.25%.

FtL >=C1·PN·DN/4 (2) in the formula.

FtL---the initial axial tensile strength of the pipe, in units of kilonewtons per meter (kN/m);

C1 --- the same formula (1), when no pressure design basis PDB test results, take C1 = 6.3;

PN, DN are the same formula (1).

Note. The tubes that are subjected to the axial force generated by the internal pressure of the pipe mainly include. a pipe whose one end is connected with a valve, a blind plug, etc., and which is not provided with a reliable buttress.

6.6.4 Water pressure leakage

Apply the water pressure of 1.5 times the pressure of the whole pipe or the whole pipe with the joint to maintain the pressure of 2.0 min, the pipe body and the joint the position should not leak.

6.6.5 Initial flexibility

The initial deflection level A and deflection level B of each sample shall meet the requirements of Table 7.

Table 7 Radial Deformation Rate and Requirements for Initial Flexibility

Flexural level

Ring stiffness rating N/m2 1250 2500 5000 7500 10000 Claim A 18 15 12 10.5 9 No cracks on the inner wall of the tube B 30 25 20 17.5 15 Tube wall structure without delamination, fiber breakage and buckling Note. The radial deformation rate for the initial flexibility of other ring stiffness tubes is performed as follows.

a) For tubes with a ring stiffness class between the standard levels, the radial deformation rates corresponding to the deflection levels A and B are linearly interpolated determine;

b) For tubes with ring stiffness class <=1250N/m2 or >=10000N/m2, the deflection levels A and B are calculated as follows.

The radial deformation rate corresponding to the deflection level A = 18 × (1250/S0) 1/3 the radial deformation rate corresponding to the deflection level B = 30 × (1250/S0) 1/3.

6.6.6 Initial hoop bending strength

The initial hoop bending strength Ftm of the pipe wall shall be determined according to the engineering design, but the minimum value is determined according to formula (3).

Ftm=4.28

kEptdelta

(D delta/2) 2

In the formula.

Ftm---the initial bending strength of the pipe wall, in megapascals (MPa);

k --- hoop bending strength special coefficient, for the tube produced by the fixed length winding process and the centrifugal casting process, k is taken as 1.0; for continuous the tube produced by the winding process, k takes 1.2;

t --- the actual thickness of the pipe wall, in millimeters (mm);

delta --- initial flexurality test of the pipe reaches the radial compression deformation amount at the deflection level B, in millimeters (mm);

D --- calculated diameter of the tube, in millimeters (mm), D = Dn t;

Dn --- the inner diameter of the tube in millimeters (mm);

Ep --- wall bending elastic modulus, in megapascals (MPa); determined by equation (4).

Ep=12×10-6S0D3/t3 (4) in the formula.

S0---initial ring stiffness in units of cattle per square meter (N/m2);

D, t is the same formula (3).

Note 1. For the FRPM pipe produced by the centrifugal casting process, when calculating Ep, the corresponding deformation of the S0 when using the deflection test reaches the deflection level A.

The value of the ring stiffness is calculated from the load value.

Note 2. When the long-term bending strain Sb is obtained through the test, the product with the same pressure level and stiffness grade may not be subjected to the initial hoop bending strength.

Inspection.

6.7 Long-term performance

6.7.1 Pressure Design Benchmark PDB

The pressure design basis PDB should meet the requirements of equation (5).

PDB>=C3·PN (5)

In the formula.

PDB---pressure design basis in MPa (MPa);

PN --- pressure rating in MPa (MPa);

C3 --- Long-term hoop tensile strength safety factor, see Table 8.

Table 8 Long-term circumferential tensile strength safety factor C3

Pressure rating PN

MPa

Coefficient C3

<=0.25 2.1

0.4 2.05

0.6 2.0

0.8 1.95

1.0 1.9

1.2 1.87

1.4 1.84

1.6 1.8

2.0 1.7

2.5 1.6

3.2 1.6

6.7.2 Long-term bending strain Sb

The long-term bending strain Sb value should meet the requirements of equation (6).

Sb>=4.28

deltas·t

(D deltas/2) 2

In the formula.

Sb---long-term bending strain;

deltas --- initial flexurality test of the pipe reaches 60% of the radial compressive deformation delta at the deflection level B, in millimeters (mm);

D, t is the same formula (3).

Note. When there is no long-term bending strain Sb value, it is recommended to calculate according to formula (6) in the design of pipeline engineering structure, where delta/2 is taken for the water supply pipeline deltas;

For the sewage pipe deltas is taken as delta/3; delta is the amount of radial compression deformation when the initial deflection test of the pipe reaches the deflection level B.

7.1 Appearance quality

Visually inspect the inner, outer and b...