working principle

The normal position before starting is that the main valve is closed and the pilot valve is opened by the spring force. Steam enters the main diaphragm chamber through the pilot valve, while a portion of the steam flows out through the control hole. When the steam flowing into the pilot valve is greater than the steam flowing out from the control hole, the control pressure in the main diaphragm chamber increases and the main valve is opened. As steam flows through the main valve, the increase in downstream pressure is fed back through the induction tube and acts on the lower part of the diaphragm of the pilot valve. This force balances the spring compression force on the upper part of the diaphragm, causing the pilot valve to gradually close and throttle, thereby maintaining the pressure in the main diaphragm chamber and controlling the opening of the main valve to deliver an appropriate amount of steam. Adjusting the spring on the diaphragm of the pilot valve can change the downstream set pressure. When steam is not needed, the pressure in the induction tube increases, the pilot valve is closed, and the control pressure is released through the control hole to tightly close the main valve.

start-up

Firstly, ensure that all shut-off valves are closed.

2. Remove the guide valve spring cap and rotate the adjusting bolt (2D) counterclockwise until the spring is relaxed. Ensure that the spring is in a vertical position and centered on the guide seat.

3. Open the shut-off valve in the following order,

a) Open the shut-off valve in front of the steam main drain valve. This will ensure that the steam before the pressure reducing valve does not contain condensed water.

b) Open the isolation valve of the induction tube.

c) Open the downstream shut-off valve.

d) Slowly open the inlet shut-off valve.

4. Slowly rotate the adjusting bolt (2D) clockwise until the downstream pressure gauge displays the required pressure reduction.

After the system pressure stabilizes, it may be necessary to adjust the pilot valve spring (2D) again. Install the spring cover and tighten the locking nut. Pay attention to tightening the flange interface of the pilot valve to ensure no leakage.