Pn on behalf of the nominal pressure, is steel elbow product under the reference temperature said crushing strength, is the production of steel pipe and accessories of the strength of the standard. Such as nominal pressure for 2. SMPa, can remember for PN2. 5 mpa. Due to butt weld bend material is different, the reference temperature is different also, cast iron and copper base temperature is 120 ℃, the steel base temperature is 200 ℃, the alloy steel reference temperature is 250 ℃. Products under the reference temperature close to room temperature compressive strength, compression strength of materials so the nominal pressure is close to room temperature compressive strength.
Ps test pressure is to test steel bend and accessories mechanical strength at room temperature and the pressures of strict performance standards. Butt welding steel elbow and steel pipe accessories before they go out, must carry out pressure test, check the strength and sealing, and products for strength test pressure is called the strength test, ps said with symbols, such as the test pressure of 4 mpa, remember to ps4MPa. From a security perspective, the test pressure must be greater than the nominal pressure, testing pressure is generally 1.5 ~ 2 times of the nominal pressure.
Pt said work pressure refers to the working pressure of the steel pipe inner flow medium.
Source: Yaang Pipe Industry Co., Limited (www.yaang.com)