You have to know these points before you buy GGC valves

Gate/Globe/Check Valve below we called “GGCV”
Everyone know GGCV are widely used in petroleum, petro-chemical, oil and gas field, oil drilling platform and other projects.
Since we know GGCV is very important and widely used in many industries, but do you know how to buy good quality GGCV ? what are the key points you have to know ?
1- Designing standard of GGCV: normally verspec produce gate valves according to API 600 or API 6D standard; globe valves according to BS1873 or ASME B16.34 standard; Check valves according to API 6D or BS 1868 Standard. When you place order to your supplier, you should mark design standard very clear.
2- Mark on casting body: normally verspec marks logo, size, pressure, body material, heat number, flow directional (if applicable) on the casting body. All mark should be casted, welding is not acceptable.
3- Valve seat: there are two difference seats verspec produced, one is welding alloys on the body, the other is replaceable seat. The price of replaceable seat will be higher than other one.
4- NACE-MR-0175: this standard request metals for sulfide stress cracking and stress corrosion cracking resistance in sour oilfield environments. So if your order valves are used under above mentioned working conditions, you should request NACE standard to your supplier, of cause price with NACE standard will be higher than without.