What is the purpose of the wire on the pressure relief valve?
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What is the purpose of this wire on the pressure relief valve? Also, does turning the nut clockwise increase or decrease it, as shown in the figure?
This post was last edited by ylb913 on 2018-8-9 at 21:13. This is called a self-acting pressure control valve; what the original poster asked about is the pressure guide tube for the controlled medium’s pressure. Self-acting pressure control valves are typically used to control the pressure behind the control valve. Judging from the piping, the diameter of the pipe on the left side is larger, and there is a vent valve at the bottom on the right side. From this, it can be inferred that the pressure on the right side of the valve is higher while the pressure on the left side is lower; the higher pressure of the fluid on the right side is used to supply pressure to the left side, with the aim of maintaining a relatively stable pressure behind the valve. From the perspective of the structure of the control valve, there is a flange at the bottom of the valve; typically, the valve element is installed in an inverted position, meaning that when the stem moves upward, the valve closes. Between the flanges on the control valve (pressure reducing valve) there is a diaphragm; the center of this diaphragm is fixedly connected to the valve stem. When the diaphragm moves upward, the valve stem moves upward as well (the valve core is in an inverted position, resulting in the valve being closed), and when the diaphragm moves downward, the valve stem moves downward as well (the valve core is in an inverted position, resulting in the valve being opened). Above the diaphragm is a spring (the force of this spring is adjustable), and below the diaphragm is the medium pressure. ——It closes the valve when the pressure behind it is high, and opens it when the pressure behind it is low.
In the attached diagram, the lines on the pressure tap tube are not visible; they are likely marks made during the piping of the pressure tap tube for the purpose of bending it. Most valves have a positive seat; is the seat of this valve positive or reverse? If in normal operation, turn the screw clockwise to close the valve.
It’s a pressure guiding tube, used to control the pressure behind the control valve
This is a self-acting pressure reducing valve that regulates itself through pressure feedback; as for whether turning the nut increases or decreases the pressure, it depends on the flow direction of the fluid in your pipeline
Pressure guiding pipeline of self-acting control valve