The difference between internal threaded valve and externall

Threaded valves (also known as wire mouth valves, threaded valves or internal tooth valves) generally refer to valves with internal or external threads on the valve body, which are mainly divided into internal threaded valves and externally threaded valves, which are connected by thread and The pipe corresponds. Usually threaded valves can only be made with small calibers. They are used for normal or low pressure projects. For example, they are not available for high pressure work. They should be used with welded link valves or flanged valves. Common threaded valves are: threaded gate valves, threaded ball valves, threaded shut-off valves, thread check valves.
  The difference between an internally threaded valve and an externally threaded valve:
  From the use: Due to the price and working flow requirements, most of the market uses internal thread valves.
  From the channel: Considering the connection of the thread, the external thread of the same diameter is smaller than the internal thread, the flow rate is fast, and the flow rate is small.
  From the appearance: the internal thread is mostly pipe thread, the external thread is mostly taper thread, and the external thread of the ferrule is the pipe thread.
  From the pressure resistance: the valve wall of the external thread of the same material is usually thicker than the internal thread (the smaller the passage, the thicker the wall), and the greater the pressure resistance, which is why the valves with large pressure levels are all external threads.
  Threaded valve seal form:
  1. Direct sealing: The internal and external threads directly seal. In order to ensure that the joints are not leaking, they are often filled with lead oil, wire hemp and polytetrafluoroethylene raw material tape; among them, the polytetrafluoroethylene raw material tape is widely used; this material has good corrosion resistance and excellent sealing effect. It is easy to use and store. When disassembling, it can be completely removed, because it is a non-stick film, which is superior to lead oil and wire.