American standard valves, German standard valves, the difference between the national standard valves

(American Standard, German Standard, National Standard) the difference between the valve：
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, etc., the national standard valve model is in accordance with the pinyin letters of the valve category to name. For example: safety valve À Butterfly valve D Diaphragm valve G Check valve H Globe valve "throttle valve L Drain valve P Ball valve Q Trap S Gate valve Z and so on.
American standard valves, German standard valves, national standard valves, there is no special specifications between the production standard and the pressure level of the difference between the valve body material and the material of the internal parts are good to say that is cast iron, cast steel, stainless steel and so on. American Standard, for example, the American Standard pressure level from 125LB to 2500LB (or 200PSI to 6000PSI), the main standard API, ANSI, usually said API, ANSI valves, that is, the American Standard valves; German standard valve pressure is usually PN10 to PN320, DIN standards; if the flange is connected to the valve, but also to use the appropriate flange standards, the world's main valve standard is also the American Petroleum Institute. Valve standards on the American Petroleum Institute API standards, the American National Standards ANSI, German standard DIN, Japanese standard JS, GB, the European Union standard EN, British standard BS.
Simply put, the American Standard valve is, according to U.S. standard design, manufacturing, production, testing of valves. German standard valve is, according to the German standard design, manufacturing and production, testing of valves. National standard valves is, according to our standard design, manufacturing, production, testing of valves.
The difference between the three roughly.
1, the flange standard is not the same.
2, the structure of the length is not the same.
3, the test requirements are not the same.

(American Standard, German Standard, National Standard) Valve Standard.
China National Standard(GB)                       American National Standard (ANSI)                           Japanese Industrial Standard (JIS)
China Ministry of Machinery Standard (B)   American Petroleum Institute standard (API)             German National Standard (DIN)
                                                                      American Society for Testing and                                French National Standard (NF)

                                                                        Materials standards (ASTM)   
                                                                      American Valve and Fitting Manufacturers                British National Standard, European                                                                                                                                                                                   Standard (BS, EN)

                                                                          Standardization(MSS)                                    Other national valve standards (OCT, IEEE, UL)