How to Guide

42
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
150 NR .47
160 NR .40
170 NR .32
180 NR .25
200 NR .20
For example, the operating pressure for 6 ” Schedule 80 PVC pipe is 280 psi. If the operating temperature is 140° F, the
maximum operating pressure is now 62 psi (280 x .22).
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
CPVC - Corzan
®
Sch. 80 200
CPVC - ChemDrain
®
* 220
Pressure/Temperature Relationship
Temperature De-Rating For Schedule 40 & 80 PVC & CPVC
* See the ChemDrain Technical Manual for more information on this product.
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.