Product Handbook 2026 - Volume 1

General information Product limitations

7

Typical 'Pressure / temperature limits' diagram and table for a safety valve:

Pressure / temperature limits Please contact: Spirax Sarco, when so required, for relevant details regarding the maximum allowable limits that the body can withstand.

     

A

Steam saturation curve



C

B















Pressure bar g

The product must not be used in this region.

A - B Flanged PN25. A - C Flanged ANSI 150.

Note: For hygienic / sanitary clamp ends the maximum pressure / temperature may be restricted by the gasket or sanitary clamp used. Please consult Spirax Sarco.

Body design conditions

PN25

DN15 - DN32

18 bar g

Maximum

Set pressure range

DN40 - DN50

14 bar g

Minimum

0.3 bar g

Minimum

-90 °C

Metal seat

Maximum

+300 °C

Minimum

-30 °C

Nitrile seat

Maximum

+120 °C

Temperature

7.4 12

Minimum

-50 °C

EPDM seat

Maximum

+150 °C

Minimum

-20 °C

Viton seat

Maximum

+200 °C

Steam

5%

Overpressure

Gas, liquid

10%

Performance data

Blowdown limits Steam, gas, liquid

10%

Derated coefficient of discharge values

Steam, gas

0.71

For further 'Pressure / temperature limits' diagram and table layouts, see TI-S24-41, pages 4 and 5.

Liquid 0.52 Designed for a maximum inlet cold hydraulic test pressure of 37.5 bar g Note: If a test gag is fitted, test pressure must not exceed 25 bar g

TI-S13-50 CH Issue 3

Pressure / Temperature Limits for Safety Valves

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