JD745 Series Diaphragm Type Multifunctional Water Pump Control Valve-China top 10 valve Manufacturers, Suppliers, Factory

01. Diameter range: DN50～1000
02. Nominal pressure: Normal PN10bar, special PN16, 25bar, high pressure piston structure can also be customized
03. Applicable medium: Non-corrosive liquids, such as tap water, fire-fighting water, etc.
04. Applicable medium temperature: Ib: -9～80℃, leakage: 0ml/min
05. The flow direction of the medium must be consistent with the arrow direction on the valve body
06. Diaphragm and valve plate sealing material: Nitrile rubber (NBR, code: N)
07. Valve body material: Normal---ductile iron (code: Q), special---cast steel WCB (code: C), SS304 stainless steel (code: B)
08. Horizontal installation with the bonnet facing upwards is recommended, or vertical installation with the bonnet facing upwards can be ok. It is strictly prohibited to install the bonnet downwards. Installing the bonnet downwards will not make the valve plate close upon its own gravity, affecting normal operation
09. This valve is mainly installed at the water pump outlet of the water supply system of high buildings and other water supply systems, which can play the role of backflow prevention, waterproof hammer, protecting the water pump and the pipeline

Working Principle

1. Pump shutdown state: The main valve plate 03 and the slow-closing valve plate 04 are fully closed under the static pressure at the outlet end and the upper chamber of the diaphragm 10, which can prevent backflow of water.
2. When the pump starts: Water pressure enters the lower chamber of the diaphragm 10 through the bypass pipe, the main valve plate 03 and the slow-closing valve plate 04 open slowly under the pressure at the inlet end and the water pressure in the lower chamber of the diaphragm 10. The opening speed can be controlled by adjusting the opening degrees of the manual control valves 12 at the inlet side and 17 at the outlet side. The greater the opening degree of the manual control valves 12 and 17 is, the faster the opening speed is. When water hammer is too large, can reduce the opening degrees of the two manual control valves appropriately.
3. During the operation of the water pump: The pressure at the water inlet end drives the main valve plate 03 and the slow-closing valve plate 04 to rise to the maximum opening degree.
4. At the moment of the water pump termination: The main valve plate 03 closes most of the opening degree rapidly under the gravity and the reverse medium pressure, to prevent backflow; the remaining opening degree is slowly closed under the combined action of the water pressure in the upper and lower chamber of the diaphragm 10 until the slow-closing valve plate 04 is closed, and the valve returns to the water pump termination state. The closing time can be adjusted by adjusting the opening degrees of the manual control valves 12 at the inlet side and the manual control valve 17 at the outlet side (3～60s adjustable).
Notes: 1. This valve requires a minimum opening pressure of 2 bar. The greater the back pressure at the outlet side is, the higher the required inlet pressure is.
2. During normal operation, the manual control valve 12 at the inlet side and the manual control valve 17 at the outlet side should have a
certain opening degree and cannot be completely closed, otherwise, it will affect normal operation.

Structure Diagram