What are the differences between American standard valves and German standard and national standard valves?

(American standard, German standard, national standard) the difference between valves:

First of all, from the standard code of each country can be distinguished: GB is the national standard, American standard (ANSI), German standard (DIN). Secondly, you can distinguish from the model, the national standard valve model is named in accordance with the pinyin letters of the valve category. For example, the safety valve is A, butterfly valve D, diaphragm valve G, check valve H, globe valve J, throttle valve L, sewage valve P, ball valve Q, trap S, gate valve Z and so on.

There is no special specification between American standard valve, German standard valve, national standard valve, nothing more than the difference between the production standard and the pressure level, the valve body material and internal material are easy to say, nothing more than cast iron, cast steel, stainless steel, etc. American Standard, for example, ranges from 125LB to 2,500 lb (or 200PSI to 6,000 psi). The standard’s main API, ANSI, is commonly referred to as API, ANSI valves. German standard valve pressure is usually PN10 to PN320, using DIN standard; If the valve is flanged, use the corresponding flange standard. The world’s main valve standards are American standard petroleum association API standard, American national standard ANSI, German standard DIN, Japanese standard JIS, GB, European standard EN, British standard BS.

Simply speaking, American standard valves are designed, manufactured, produced and tested according to American standards. German standard valves are designed, manufactured, produced and tested according to German standards. National standard valve is, according to China’s standard design, manufacturing, production, detection of valves.

The difference between the three is roughly: 1, the standard of flange is not the same; 2, the length of the structure is different; 3. The inspection requirements are different.

American standard valve, German standard valve, national standard valve before installation need to carry out the necessary valve inspection and test work, in order to ensure the normal use in the working condition, but also to do a good job on the safety of a protection work. The test pressure shall be the highest working pressure, the lowest working pressure and the lowest working pressure respectively. Sensitive action and no leakage of steam shall be considered as qualified.

American standard valve pressure test standard: is 1.5 times the nominal pressure, the test time is 5min, the test time of the valve body is not broken, no deformation, the valve does not leak water, the pressure gauge does not drop as qualified. After the strength test is qualified, the tightness test is carried out again. The tightness test pressure is equal to the nominal pressure. The valve has no leakage during the test time, and the pressure gauge does not drop to be qualified.