Pressure rating of all thermoplastics are decreased at the temperature increases. This chart may be use for piping, fittings, filter chambers and a pump's maximum working* pressure. If a filter chamber is rated for 100 PSI at 73 F, the new pressure rating is reduced by taking the below correction factor, listed by material and temperature, and multiplying. Example: at 90 F, the pressure rating for a CPVC material would be 86 PSI. For PVDF at 160 F, the pressure would be 54 PSI.
This correction is due to thermal distortion and loss of tensile strength of the material. This chart is used only as a guide. The manufacturer of the equipment should be contacted regarding the actual pressure rating of the equipment and the affect of temperature.
* The pump's working pressure is defined as the total system pressure. It is a combination of the pump's generated pressure (TDH) and the suction pressure. The pump's performance is not affected by temperature.
Temperature Correction Factors:
Temperature (° F) vs. Pressure
|Operating Temp. ° F||Factors|
PVC material has not been included in this chart - The maximum temperature limit is usually 140 F.
CPVC material limits for most molded products is 200 F.
Polypropylene material limits for most molded products is 180 F.
PVDF (Kynar) material limits for most molded products is 280 F.
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