3-way Control is used for:
- On-Off Control valves.
- Regulating valves which need operate with low pressure differential.
- Dirty water as raw irrigation water and sewage water.
- Where usage of external control media (such as pressurized air) is required.
2-way pilot valve
In a two-way pilot valve, the upstream side of the valve is connected by a control tube to the control chamber and to the downstream side of the valve. Two flow restrictors are assembled. One (orifice or needle valve) assembled upstream of the control chamber and the other (a pilot valve) assembled on the downstream side and modulates in response to the pipeline pressure. The relative opening of both restrictors dictates the position of the main valve. This type of control principal provides very accurate and sensitive regulation but creates considerable pressure loss even if no regulation is needed.
2-way Control is used when:
- Minimal pressure differential at all operating conditions allows it.
- Sensitive (fast response) regulation is required.
- Relatively high quality water.