Differences and relations among nominal pressure, test pressure and working pressure


1. Nominal pressure

(1) nominal pressure - the compressive strength of the product at the reference temperature, expressed in PN, unit: MPa.

(2) reference temperature: different materials have different reference temperatures. If the reference temperature of steel is 250 ° C

(3) nominal pressure 1.0MPa, recorded as PN 1.0MPa


2. Test pressure

(1) pressure for strength test of products, expressed in PS.

(2) the test pressure is 4.0Mpa, which is recorded as PS 4.0Mpa.


3. Working pressure

(1) the pressure of pipes and fittings under normal conditions is expressed in Pt.

(2) t × 10 = maximum working temperature of the product.

(3) the maximum temperature of the medium is 300 ° C, and the working pressure is 10MPa, which is recorded as P 30 10MPa.


4. Relationship among test pressure, nominal pressure and working pressure:

Ps > PN > Pt

The nominal pressure of the valve refers to the design working pressure of the valve, and the pressure grade is divided according to the standard.

The working pressure of the valve is the actual pressure of the user in the application environment, which should be less than the nominal pressure of the valve.