Thermoplastic Pipes - Strength Derating vs. Temperature
Thermoplastic materials loose strength to pressure and tension with increasing temperature. The table below can be used as a guide to common thermoplastics and their derated strength with temperature. Manufacturing data should always be consulted.
| Derating Factor | |||||||
|---|---|---|---|---|---|---|---|
| Temperature | PVDF | CPVC | PVC | PB | PEX | PE | |
| (oC) | (oF) | ||||||
| 21 | 70 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| 27 | 80 | 0.9 | 1.0 | 0.9 | 1.0 | 0.9 | 0.9 |
| 32 | 90 | 0.9 | 0.9 | 0.8 | 0.9 | 0.9 | 0.9 |
| 38 | 100 | 0.8 | 0.8 | 0.6 | 0.9 | 0.9 | 0.8 |
| 43 | 110 | 0.8 | 0.8 | 0.5 | 0.8 | 0.8 | 0.8 |
| 49 | 120 | 0.7 | 0.7 | 0.4 | 0.8 | 0.8 | 0.7 |
| 54 | 130 | 0.7 | 0.6 | 0.3 | 0.7 | 0.8 | 0.5 |
| 60 | 140 | 0.6 | 0.5 | 0.2 | 0.7 | 0.7 | 0.4 |
| 66 | 150 | 0.6 | 0.5 | 1) | 0.7 | 0.7 | 0.2 |
| 71 | 160 | 0.5 | 0.4 | 1) | 0.6 | 0.7 | 1) |
| 82 | 180 | 0.5 | 0.3 | 1) | 0.5 | 0.6 | 1) |
| 93 | 200 | 0.4 | 0.2 | 1) | 0.4 | 0.5 | 1) |
| 104 | 220 | 0.4 | 1) | 1) | 1) | 1) | 1) |
| 121 | 250 | 0.4 | 1) | 1) | 1) | 1) | 1) |
| 138 | 280 | 0.3 | 1) | 1) | 1) | 1) | 1) |
1) The thermoplastic is not resistant for long term service at this temperature. Operating conditions should be avoided.
- PVDF - PolyVinylidene Fluoride
- CPVC - Chlorinated Polyvinyl Chloride
- PVC - Polyvinyl Chloride
- PB - Polybutylene
- PEX - Cross Linked Polyethylene
- PE - Polyethylene
Plastic Pipes Temperature Derating Diagram
Example - Higher Temperature and Reduced Strength
If the operating pressure for a 6" Schedule 80 CPVC pipe is 167 psi, the maximum operating pressure at 150 oF (66 oC) is reduced to
(167 psi) 0.5
= 83.5 psi
Related Topics
• Material Properties
Properties of gases, fluids and solids. Densities, specific heats, viscosities and more.
• Pressure Ratings of Pipes and Fittings
Pressure ratings of pipes and tubes and their fittings - carbon steel , stainless steel, plastic, copper and more.
Related Documents
ASTM D2513 - Thermoplastic Gas Pipes - Dimensions
Dimensions of thermoplastic pressure pipes.
ASTM D3034 PSM PVC Sewer PIpe - Dimensions
Dimensions of PSM PVC sewer pipe.
ASTM D3035 - Polyethylene PE pipes - dimensions
Dimensions of PE pipes based on controlled outside diameter.
ASTM F876 - PEX Tube - Dimensions
Dimensions of PEX tubes.
BS 7291 - Thermoplastics Pipes for Hot and Cold Water - Dimensions
Dimensions of thermoplastic pipes - PEX and PB according BS 7291.
CPVC Tubes - Pressure and Temperature Ratings
CTS (Copper Tube Sized) CPVC (Chlorinated Poly Vinyl Chloride) tubes temperature and pressure ratings.
EN 1329 - PVC Piping for Soil and Waste Discharge - Dimensions
Dimensions of PVC pipes according EN 1329.
EN 1401 - PVC Piping Systems for Non-Pressure Underground Drainage and Sewerage
Dimensions of PVC pipes according EN 1401.
EN 1453 - PVC Piping with Structured Walls - Dimensions
Dimensions of PVC pipes with structured walls according EN 1453.
ISO 11922 - Thermoplastics Pipes for the Conveyance of Fluids - Dimensions
Dimensions of plastic pipes according ISO 11922 - metric and imperial units.
ISO 4437 - PE Pipes for Gaseous Fuels Supply - Dimensions
Dimmensions of PE pipes for gaseous supply according ISO 4437.
PE (PolyEthylene) Pipes - Pressure Ratings vs. Size
Water pressure ratings for schedule 40 and schedule 80 Polyethylene plastic pipes
PE (PolyEthylene) Pipes - Pressure vs. Temperature Ratings
Polyethylene pipe temperature and maximum operating pressure.
Plastic Pipes - Maximum Operating Temperatures
Piping materials like ABS, PE, PVC, CPVC, PB, PP and SR and pressure and operating temperature limits.
Plastics - Recycling Codes and Labeling
Symbol codes and labeling used for recycling plastic products like bottles, containers and packagin.
PVC Pipes - Pressure Ratings vs. Size
Maximum operating and required burst pressure of PVC - Polyvinyl Chloride - pipe fittings.
Steel Pipes - De-Rating vs. Temperature
Temperature derating factor for steel pipes.