Pressure reducing valve classification
There are many kinds of pressure reducing valves, so pay attention to which pressure reducing valve is used for which occasion. We will sort out the classification of three types of steam pressure reducing valves and how to classify them according to their construction.
1. The action pressure reducing valve in the pressure reducing valve Compared with other pressure reducing valves, it is a valve with simple operation and is a direct action pressure reducing valve with a flat diaphragm or a bellows. Because it is a self-contained structure, there is no need to install external sensing lines downstream. It is an economical of three pressure reducing valves designed for low to medium flow rates.
2. Piston pressure reducing valve: This pressure reducing valve integrates the pilot valve and the main valve. The design of the pilot valve is similar to that of a direct acting pressure reducing valve. Exhaust pressure from the pilot valve acts on the piston, causing the piston to open the main valve.
This design will use inlet pressure to open the main valve if it is too large to open directly. Therefore, this type of pressure reducing valve has higher capacity and accuracy than direct acting pressure reducing valves for the same pipe size. Like the direct-acting safety valve, the pressure inside the pressure reducing valve is sensed, so there is no need to install a sense wire outside.
3. Membrane pressure reducing valve in pressure reducing valve: In this type of steam pressure reducing valve, the double diaphragm replaces the piston in the inner pilot pressure reducing valve. This increased diaphragm area can open a larger main valve with a larger capacity than an internal pilot piston pressure relief valve for the same pipe size. In addition, the diaphragm is more sensitive to pressure changes with an accuracy of 1%. The higher accuracy is due to the positioning of the downstream sensing line, where there is less gas or liquid turbulence.
Pressure relief valves reduce system pressure without overloading the hydraulic system. The relief valve prevents overloading of the hydraulic system and ensures safety. Using the principle of balance between the control pressure and the spring force, the opening of the slide valve is changed, and the system pressure is controlled through the opening. The structure is basically the same, except for the way the oil leaks.