How to Guide
40
Plastics Technical Manual
DESIGN & ENGINEERING DATA
The operating pressure of PVC and CPVC pipe will be reduced as the operating temperature increases above 73° F. To calculate
this reduction, multiply the operating pressures shown on the previous pages by the correction factors shown below:
Operating Correction Factors
Temperature (°F) PVC CPVC
73 1.00 1.00
80 .88 1.00
90 .75 .91
100 .62 .82
110 .50 .77
120 .40 .65
130 .30 .62
140 .22 .50
/3
/3
/3
/3
/3
For example, the operating pressure for 6
w
Schedule 80 CPVC pipe is 280 psi. If the operating temperature is 140° F, the
maximum operating pressure is now 140 psi (280 x .50).
Maximum Operating Temperatures
For Various Piping Systems
(de-rate operating pressure at temperatures in excess of 73°F)
Piping Max. Operating
System Temp. °F
ABS 140
PVC 140
CPVC - FlowGuard Gold
®
CTS 180
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®
Sch. 80 200
CPVC - ChemDrain
®
Pressure/Temperature Relationship
Temperature De-Rating For Schedule 40 & 80 PVC & CPVC
4FFUIF$IFN%SBJO5FDIOJDBM.BOVBMGPSNPSFJOGPSNBUJPOPOUIJTQSPEVDU
NOTICE: The maximum recommended temperature and de-rating of working pressure applies to both heat generated from fluid
being distributed through pipe system and heat generated from sources external to the pipe system.