Chlorinated PVC pipe in the industrial application, generally used in chemical, paper and mining production, mainly used to transport a certain temperature, a certain pressure and corrosive liquids.
1, raw material selection and material formulations
CPVC pipe for the chemical plant, requiring Vicat softening point temperature ≥ 110 ℃, the choice of CPVC resin chlorine content ≥ 61%. A small amount of SG5-type PVC resin, the extrusion molding CPVC pipe material formulations can refer to the following program preparation (mass).
Chlorinated Polyvinyl Chloride (CPVC) 95 Titanium **** (TiO2) 0.15
Polyvinyl chloride (PVC SG5) 5 Carbon black 16g
Stabilizer (available organic tin or lead compound stabilizer) 5 ~ 9
Other adjuvants such as impact modifier (CPE), lubricants (HSt, OPE) and fillers (CaCO3), etc., according to the CPVC pipe application conditions need to add the amount of discretion.
2, forming process
Industrial CPVC pipe extrusion molding process temperature, due to the main raw material in some PVC resin to add, can be slightly lower than the PVC resin without adding the formula to the extrusion temperature (generally about 5 ℃ lower), mold temperature control and other All aspects of the operation method can be fully reference to "chlorinated polyvinyl chloride tube extrusion molding process - forming process" content production.
3, the quality of industrial CPVC pipe
Industrial quality CPVC pipe quality requirements should be consistent with GB / T 18998.2-2003 standards.
① pipe size according to the series S is divided into S10, S6.3, S5, S4 four series, tube specifications labeling method such as S4 = dn50 × en5.6 (dn for the nominal diameter, en is the nominal wall thickness).
② Corresponding to the nominal pressure PN series S, the standard size than the SDR and pipe specifications in Table 1.
Table 1 Pipe size Dimensions Unit: mm
Nominal diameter dn Nominal wall thickness en
Tube series S
S10 S6.3 S5 S4
Standard size ratio SDR
SDR2l SDR13.6 SDRll SDR9
Nominal pressure PN (or design pressure PD) / MPa
PN1.0 PN1.6 PN2.0 PN2.5
20 2.0 (0.96) 2.0 (1.5) 2.1 (1.9) 2.3
25 2.0 (1.2) 2.1 (1.9) 2.3 2.8
32 2.0 (1.6) 2.4 2.9 3.6
40 2.1 (1.9) 3.0 3.7 4.5
50 2.4 3.7 4.6 5.6
63 3 4.7 5.8 7.1
75 3.6 5.6 6.8 8.4
90 4.3 6.7 8.2 10.1
110 5.3 8.1 10 12.3
125 6.0 9.2 11.4 14
140 6.7 10.3 12.7 15.7
160 7.7 11.8 14.6 17.9
180 8.6 13.3
200 9.6 14.7
225 10.8 16.6
Note: Pipe brackets with the specifications of the pipe to do the hydraulic test in brackets within the wall thickness of the calculation test.
③ pipe appearance quality requirements are as follows. The inside and outside of the tube should be smooth, smooth, not allowed to have bubbles, scratches, depression, impurities and uneven color defects. The pipe end should be cut flat and perpendicular to the tube centerline.
④ pipe wall is not allowed to light.
⑤ pipe length is generally 4m or 6m, can also be determined according to user requirements. The allowable deviation of the length is ± 0.4% of the length.
⑥ pipe diameter and deviation of the average diameter and non-round, should be consistent with the provisions of Table 2.
Table 2 Average outside diameter and deviation, non-roundness maximum unit: mm
Average Outer diameter non-roundness max. Mean outer diameter non-roundness maximum
Nominal Outer Diameter dn Allowable Deviation Nominal Outer Diameter dn Allowable Deviation
20 +0.20 0.5 40 +0.20 0.5
25 +0.20 0.5 50 +0.20 0.6
32 +0.20 0.5 63 +0.30 0.8
75 +0.30 0.9 160 +0.50 2.0
90 +0.30 1.1 180 +0.60 2.2
110 +0.40 1.4 200 +0.60 2.4
125 +0.40 1.5 225 +0.70 2.7
140 +0.50 1.7
⑦ pipe wall thickness and deviation of any point should be consistent with the provisions of Table 3.
Table 3 wall thickness en and deviation unit: mm
Nominal wall thickness en Permissible deviation Nominal wall thickness en Allowable deviation
2.0 <en? 3.0 + 0.50 10.0 <en? 11.0 +0.130
3.0 <en ≤ 4.0 +0.60 11.0 <en ≤ 12.0 +0.140
4.0 <en ≤ 5.0 +0.70 12.0 <en ≤ 13.0 +0.150
5.0 <en ≤ 6.0 + 0.80 13.0 <en ≤ 14.0 +0.160
6.0 <en ≤ 7.0 +0.90 14.0 <en ≤ 15.0 +0.170
7.0 <en ≤ 8.0 +0.100 15.0 <en ≤ 16.0 +0.180
8.0 <en ≤ 9.0 +0.110 16.0 <en ≤ 17.0 +0.190
9.0 <en ≤ 10.0 +0.120 17.0 <en ≤ 18.0 +0.200
Note: wall thickness en = 2mm deviation for the industrial chlorinated PVC pipe extrusion
⑧ The physical properties of the pipe are shown in Table 4. The mechanical properties of the pipe are shown in Table 5.
Table 4 Physical properties
Project Indicators Project Indicators
Density 1500 ~ 1650kg / m3 longitudinal retraction rate ≤ 5%
Vicat softening temperature ≥ 110 ℃ chlorine content ≥ 60% (mass percentage)
Table 5 Mechanical properties
Item Index Test parameters
Static hydrostatic test without rupture without leakage temperature / ℃ hydrostatic stress / MPa time / h
20 43 ≥1
95 5.6 ≥ 165
95 4.6 ≥1000
Thermal stability test in hydrostatic state 95 3.6 ≥8760
Drop hammer impact test damage rate TIR ≤ 10% test temperature (0 ± 1) ℃ drop weight and height see Table 6 and Table 7
Table 6 Size of drop hammer hammer Unit: mm
Model Rs d ± 1 ds α / (°)
d25 50 25 any arbitrary
d90 50 90 any arbitrary
Table 7 Recommended drop weight unit: kg
0.5 1.6 4.0 10.0 1.0 2.5 6.3 16.0
0.8 2.0 5.0 12.5 1.25 3.2 8.0
⑨ pipe hydraulic test conditions as specified in Table 8.
Table 8 Hydraulic test
Test temperature / ℃ 20 80 No rupture, no leakage
Hydrostatic stress / MPa 17 4.8
Test time / h ≥ 1000 1000