Quick answer: valve selection comes down to five questions — what the valve must do (isolate or regulate), the medium, the temperature and pressure, how often it will be operated, and what the piping and project specification require. Answer those and the valve type usually selects itself.
The five selection questions
| Question | If the answer points one way | Read |
|---|---|---|
| Isolate or regulate? | Isolate: gate, ball, butterfly. Regulate: globe | Gate valve vs globe valve |
| What is the medium? | Clean hydrocarbon: carbon steel. Corrosive: stainless or higher | WCB vs stainless steel |
| What is the temperature? | Above or below the limits of carbon steel changes the material family | Material selection guides |
| How often is it operated? | Frequent operation rules out a gate valve for regulation duty | Valve type comparisons |
| How is it joined? | Flanged for maintenance access, welded where leakage paths must be minimised | Flanged vs butt-weld |
The guides in this section
- Gate valve vs globe valve — isolation against regulation
- WCB vs stainless steel valve bodies — the material decision
- Cast vs forged valve bodies — manufacturing route and suitability
- Flanged vs butt-weld ends — installation, maintenance and cost
待补内容位：可后续补充：球阀 vs 蝶阀、锻钢阀与铸钢阀的价格逻辑、法兰等级与压力等级对照表。