Relationship Between Valve Temperature and Pressure

Valve operating temperature and pressure are intrinsically linked and mutually interactive. Temperature acts as the dominant influencing factor. Valves rated for a specific pressure are only applicable within a corresponding temperature range, and temperature variations will alter their permissible working pressure.

For instance, a carbon steel valve with a nominal pressure of PN100 has a maximum working pressure of 10 MPa at a medium temperature of 200°C. The value drops to 5 MPa at 400°C, and 4.5 MPa at 450°C.

The temperature resistance of enameled valves is restricted by sealing materials, with a maximum service temperature not exceeding 150°C.

Service Pressure of Valves

A valve's allowable service pressure is determined by its manufacturing material.

Gray cast iron valve: Maximum nominal pressure PN16

Malleable cast iron valve: Maximum nominal pressure PN25

Ductile iron valve: Maximum nominal pressure PN40

Copper alloy valve: Maximum nominal pressure PN25

Titanium alloy valve: Maximum nominal pressure PN25

Carbon steel valve: Maximum nominal pressure PN320

Alloy steel valve: Maximum nominal pressure PN300

Stainless steel valve: Maximum nominal pressure PN320

Plastic valve: Maximum nominal pressure PN6

Ceramic, glass and enameled valve: Maximum nominal pressure PN6

Fiberglass reinforced plastic valve: Maximum nominal pressure PN16