In some seriously application , such as medium full of sand and mud( eg in Huang River and sewage water treatment system ) , general valve can not run well and easily clog ,even will lead to the failure of the valve. Larger foreign material will make the disc stuck ,and result in lax sealing. Beside that ,big noise will appear because of large water hammer impact when the valve closed. Furthermore , some accidents will happened. Tube force control valve is developed to solve these problem.Working principle
Valve opening : when the pump starting work ( fig 1), the water will flow through bypass pipe with check valve ,then flow into control room. Large disc as well as small disc ,will open slowly in the function of water from the inlet (as the fig2). To meet the requirement of the working condition ,the speed of valve opening can be controlled by adjusting the bypass ball valve
Valve closing : As the reduction of flow rate and pressure from the valve inlet , the large disc will close quickly in the self gravity when the pump stop work. The water is cut off , small disc will automatic open as spring . Afterword ,most of back flow water will be remove ,and the water hammer eliminate ,as the fig 3 stated . Meanwhile ,some of the flow back water will enter into the upper room by bypass line ,and push the control stem move downward ,small valve stem is closed ,and the water is fully cut off ( as fig4). The time of closing valve can be controlled by adjusting the bypass valve ,so the peak value of water hammer is controlled in some range .Product characteristic
1,Easy to maintain
Less fault point without external power . The key parts of the valve is made by high quality material, without any maintain . The filter in external line has self washing function .
Innovative structure , simple structure ,small volume ,and reliable running performance .
Due to driving by medium and connecting with pump aotomatically , the valve reduce the cost of operational people greatly .
4,Open the pump slowly
Only the inlet pressure up to the presetting value after opening the pump ,the valve can be opened . The current of starting pump is reduced to improve the security of motor and electric control system .
5,The valve opens quickly and closing slowly , which eliminating the water hammer and grantee the system safety .
6,The disc of valve is oblique butterfly type ,and water is flow horizontal ,so the loss of energy is less .
7,Tight sealing , nearly zero leakage
As metal-soft sealing or metal sealing structure is adopt , torque of friction will be greatly reduced; eccentric and oblique sealing pair, make the travel of closing valve becoming shorter , reduce the movement of distance sealing ring ,torque of friction become lower . So the valve can be opened in a moment . Further more , sand- proof function and pressure automatic compensation is also designed .
8,Because of butterfly structure ,the valve has light weight and small volume ,and saves the construction cost . Without hydraulic control unit ,the cost is reduced and performance is increased . Due to less power is consumed ,it realizes energy-saving goal .
9,There are two types , diaphragm type and piston type ,widely use in all kinds of medium .To grantee the medium is clean before entering into diaphragm ,a filer have to be installed to remove the particles of the sewage . The filter have self washing function .Because a special unit is designed below the filter, slag discharging will be done periodically .
10,To meet the requirement of different operating conditions , control type is optional . Flow rate of the valve can be adjusted by manual or electric actuator .