(FOOT VALVES, REFLUX VALVES, NON-RETURN VALVES & BUTTERFLY VALVES) VF, VR, VN & VB SERIES

All Centrifugal end suction pumps will deliver water only when the entire pump casing and suction pipe is filled with water and  without any air pockets (Priming). To achieve this, foot valve is necessary. Foot valve is placed at the lower end of the suction pipe of a centrifugal end suction pump  to retain  water  in  the pump casing and suction pipe while pump is at rest.  Consequently, when the pump is again started it does not  have to be primed again and pump will deliver water instantaneously. It has a strainer  at bottom portion, hence, it prevents any  foreign particle entering the pump through the suction pipe.

Reflux valve is fitted generally in the delivery pipeline to avoid water hammer, upthrust and back spin effects in the pumping system.  Reflux valve  can also be used anywhere in the  suction line of which the bottom end is inserted into a bore pipe or tube well. Non-return  valves are fitted generally in the pipeline to prevent back water pressure and safe guards the entire pumping unit.

DESCRIPTION
C.R.I energy efficient frictionless foot valves and reflux valves  are basically swing type non return valves. Foot valves are available in Screwed and Flange type construction. Reflux valves (Check valves) have threaded portions at both the ends. They are specially designed to give an unrestricted smooth flow of water and thus reduces the frictional losses to a minimum.  Frictional losses in a valve can be defined by hf = K V2 / 2g where �hf� is frictional losses in a valve, �V� is the velocity of flow in the suction pipe and �K� is the friction factor. The C.R.I  frictionless foot valve has �K� value less than 0.8 and �K� value for reflux  valves  are less than 0.5, thereby it reduces additional load on prime mover and there by increases the discharge.

Applications
Foot valve: It is suitable for all Centrifugal end suction pumps, Non-Self priming pumps and centrifugal mono block pumps