YDK Pressure Reducing Valve – Model: KCV200

In high-rise buildings, domestic water supply pumping stations, and fire protection (PCCC) networks, fluid pressure on lower floors is often significantly higher due to differences in elevation head. The YDK Pressure Reducing Valve, Model KCV200, provides an automatic solution for regulating and maintaining stable downstream pressure at a preset value, protecting the piping system and downstream water-using equipment from the risk of excessive pressure.

Construction of YDK Pressure Reducing Valve – Model KCV200

Like other hydraulic control valve series, the YDK pressure reducing valve has a relatively complex structure consisting of multiple components. Below are the 17 structural components taken directly from the Model KCV200 product catalogue:

1. Body: Made of GGG50 ductile iron with corrosion-resistant Epoxy coating, providing high mechanical strength.
2. Seat: Precision-machined brass, providing good wear resistance.
3. Platen: Made of CS carbon steel.
4. Sealing: Made of EPDM rubber to provide a leak-proof seal.
5. Disc: Made of GGG50 ductile iron.
6. Diaphragm: Reinforced EPDM rubber diaphragm that responds to pressure in the control chamber.
7. Platen: Made of CS carbon steel.
8. Nut: Made of stainless steel.
9. Stem: Made of SS410 stainless steel.
10. Spring: Made of stainless steel.
11. Plug: Made of SS304 stainless steel.
12. Bonnet: Made of GGG50 ductile iron.
13. Bolts: Stainless steel A2-70 (SS304).
14. Needle Valve: Made of SS304 stainless steel, regulating the flow into the diaphragm chamber.
15. Inlet Pressure Gauge: Displays the pipeline pressure upstream of the valve.
16. Outlet Pressure Gauge: Displays the reduced pressure downstream of the valve.
17. Pilot Valve: Made of SS304 stainless steel, serving as the sensing and outlet pressure adjustment component.

YDK Pressure Reducing Valve – Model KCV200 Dimensions

Pressure Stabilization Principle of the YDK Pressure Reducing Valve

The YDK pressure reducing valve operates based on automatic pressure differential control through the Pilot Valve assembly:

1. When the outlet pressure rises above the preset value: The feedback pressure acts on the Pilot Valve diaphragm, causing the Pilot Valve passage to close slightly. Fluid is retained in the control chamber above the main valve bonnet, compressing the diaphragm and pushing the valve disc downward. This reduces the flow area and brings the outlet pressure back to the preset level.
2. When the outlet pressure falls below the preset value: The Pilot Valve opens further, releasing some fluid from the control chamber. The reduced pressure in the upper chamber allows the main valve disc to rise, increasing the flow passage to compensate for the pressure drop.
3. Balanced state: The valve continuously performs this automatic adjustment, maintaining stable downstream pressure regardless of fluctuations in inlet pressure or water consumption.

Technical Notes for Installing & Operating the YDK KCV200 Pressure Reducing Valve

1. Bleeding Air from the Diaphragm Chamber: During initial installation or after maintenance, slightly loosen the air-release screw on the valve bonnet to completely remove air from the diaphragm chamber. Trapped air can cause the valve to “jerk” or result in unstable pressure reduction.

2. Pressure Adjustment Procedure on the Pilot Assembly:

• Open the isolation valve downstream of the pressure reducing valve.
• Turn the bolt on top of the Pilot assembly clockwise to INCREASE the outlet pressure.
• Turn it counterclockwise to DECREASE the outlet pressure.
• Observe the outlet pressure gauge until the needle reaches the desired value, then tighten the locking nut.

3. Install a Y-Strainer Upstream: A Y-strainer must be installed upstream of the pressure reducing valve to prevent debris, sand, and other particles from entering the small passages of the Pilot assembly and causing blockages.

The experienced team at An Phu Thanh is always ready to provide consultation and quotations for YDK pressure reducing valves suitable for each customer’s project requirements. Contact us via Hotline/Zalo: 0946 729 913 for a prompt response.