Empty check valve
Technical Parameter

Nominal diameter: DN50~250mmNominal pressure: PN20MPaWorking temperature: ≤160℃Design and manufacture: ASME B16.34, JB/T3595, E101Pressure and temperature: ANSI B1 6.34, JB/T74, JB/T3595, E101Structure length: ANSI B16.10, E101, GB/T15188.1, JB/T2766Butt welding connection size: ASME B16.25, GB/T12224, E101Inspection and testing: ISO5208, GB/T13927, JB/T3595


Product Detail

Product Description

The empty discharge check valve is installed on the outlet pipeline of the high-pressure feed pump of the thermal power unit to prevent the backflow of the feed water and protect the feed pump. The valve works in conjunction with the automatic recirculation bypass valve of the small flow of the pump. When the feed pump is under low load or the outlet shut-off valve is closed, the automatic recirculation bypass valve should be in the open position to ensure the safe operation of the pump. When the empty exhaust check valve opens, the recirculation bypass valve automatically closes. Not suitable for medium containing solid particles and high viscosity.


Product Features

Open the outlet valve, the feed water pump starts, and after the feed water reaches a certain pressure, the valve disc will rise to a certain height under the action of the feed water pressure, push it away from the valve seat, and the feed water will flow out. At the same time, due to the rise of the valve disc, the connecting rod is driven to rotate, and the valve plate of the exhaust port is toggled, so that the recirculating blade valve moves down and closes the exhaust port. When the water supply flow decreases, the valve disc falls, pushes the connecting rod to open the emptying valve plate, and opens the recirculation door to maintain the small allowable flow of the pump. When the pump is stopped, the valve disc will automatically drop, closing the valve port channel to prevent the damage of the high-pressure water hammer water supply system. The valve works in conjunction with the recirculation bypass valve to maintain the safe operation of the system. The main disc moves up and down, and when the medium flows back, the passage is closed by means of the medium pressure and the action of the spring, and the bypass valve is opened at this time. When the main disc is fully opened, the bypass valve is closed. The valve disc seal is made of stainless steel surfacing, which is wear-resistant, scratch-resistant and reliable in sealing. ·The valve should be installed vertically.


Main material

Part NameMaterial
Body, connecting flange, exhaust flange, flange coverCarbon cast steel
Guide shaft, fork, bushing, slider, exhaust sleeve, exhaust discStainless steel
Disc, disc body, disc shaft, connecting forkHigh quality carbon steel
BushingCast aluminum bronze
Bolts and nutsHigh quality carbon steel


Main external connection dimensions

DNLDD1D2D6bZ-dff2HWT(kg)
100430360292245138668-4136630285
1505504403603051908212-Ф4836650510
17561047539443402148412-Ф4836685700
22590058048341826810012-Ф58367651105
25090067057250831911016-Ф58367801330