In order to achieve the oil and gas flow control, oil and gas valves should have these following basic properties: sealing, compressive strength, safety, adjustability, flow-through of fluid and switching flexibility.
For the gas media with high pressure, flammability and explosive performance, we must first solve the sealing problem and then consider the special conditions requirements.
1. When in wet natural gas, such as hydrogen sulfide and carbon dioxide, the material of the valve
body should be special.
2. If there are brine, residual acid and other corrosive medium in wellhead equipment or gathering system, then the material of valve body should be anticorrosive.
3. Dust and solid particles can accelerate the erosion, abrasion of valve closure member, quickly making the sealing fail.
4. In highlands, deserts, alpine regions and other outdoor places, valve material will be fragile and easily out of shape.
5. Oil and gas valves, which are used for long distance transport, are required to have long service life (equivalent to pipeline life). And they can not be changed for several decades.
All these show that the oil and gas valves are different from other common valves. They have to be high reliable in harsh conditions to meet the high strength and non-disclosure requirements.