Fluid flow control valves

Claim 2

A priming device for a centrifugal liquid pump including: a chamber communicating with the suction side of the pump; a passageway communicating with a vacuum source; a first opening from said passageway to said chamber; a second opening from said passageway to atmosphere; a double headed valve member of which the valve heads are arranged to close said first and second openings respectively; and a float member arranged in said chamber and connected to said Valve member to transmit movement thereto, said float member controlling said valve in response to a low liquid level in said chamber to cause said one valve head of said float member to close said second opening while maintaining the first opening open, said float member controlling said valve in response to a higher liquid level in said chamber to cause said other valve head to close the first opening while maintaining the second opening open; said valve head for closing the second opening comprising a generally annular valve head mounted for limited axial sliding movement upon the valve member, a valve seat in said second opening at times mating with said annular valve head, a conduit extending through said annular valve head and terminating in a valve seating coaxial with the valve head, a smaller valve head fixed to said valve member and arranged to cooperate with the valve seating in said annular valve head, and a helical compression spring located coaxially around said valve member and said annular valve head externally of said second opening, said spring being stressed between a radially extending abutment of said smaller valve head and the body of the device defining said second opening so as to bias said valve toward a position opening said second opening; the weight of the float member being sufficient to overcome the force of said spring and hold the valve in the position closing said second opening when unsupported by liquid present in said chamber.

Claim 3

A fluid flow control valve comprising a branched passageway communicating on the one hand with atmosphere and on the other hand with a chamber intended to contain liquid and gas, a double headed valve member arranged in said passageway for movement from a first position in which it closes said passageway to atmosphere while opening it to said chamber to a second position in which it closes said passageway to said chamber and opens it to atmosphere, and float means disposed in said chamber and coupled to said valve member, the arrangement being such that when the liquid level in said chamber is below a given level the said valve member is in the first position whereas upon rise of said liquid level above the given level the float means serves to cause movement of the valve member to said second position, said valve member being provided with an auxiliary closure means for closing said passageway to said chamber, said auxiliary closure means being mounted for limited movement relatively to said valve member in the direction of movement of said valve member between the said first and second positions, whereby while said valve member remains in the first position said auxiliary closure means can be moved into a position closing the passageway to said chamber, said auxiliary closure means being directly connected with a second float means for moving it into a closing position upon rise of the liquid level within said chamber, said auxiliary closure means being of greater effective area than a part of the valve member for closing said passageway to atmosphere and being so constructed that it can undergo further movement in the closing direction upon initial closure of the passageway to said chamber, whereby upon movement of the auxiliary closure means by said second float means into an initial closing position whilst the said passageway is subjected to suction a reduced pressure is established in said passageway which moves the auxiliary closure means further in the closing direction until, upon completion of the available relative movement between the auxiliary closure means and the valve member, the latter becomes moved to open the passageway to atmosphere.

Claim 4

A fluid flow control valve comprising a branched passageway communicating on the one hand with atmosphere and on the other hand with a chamber intended to contain liquid and gas, a double headed valve member arranged in said passageway for movement from a first position in which it closes said passageway to atmosphere while opening it to said chamber to a second position in which it closes said passageway to said chamber and opens it to atmosphere, and float means disposed in said chamber and coupled to said valve member, the arrangement being such that when the liquid level in said chamber is below a given level the said valve member is in the first position whereas upon rise of said liquid level above the given level the float means serves to cause movement of the valve member to said second position, said valve member being provided with an auxiliary closure means for closing said passageway to said chamber, said auxiliary closure means being mounted for limited movement relatively to said valve member in the direction of movement of said valve member between the said first and second positions, whereby while said valve member remains in the first position said auxiliary closure means can be moved into a position closing the passageway to said chamber, said auxiliary closure means being directly connected with a second float means for moving it into a closing position upon rise of the liquid level within said chamber, said auxiliary closure means being of greater effective area than a part of the valve member for closing said passageway to atmosphere and being so constructed that it can undergo further movement in the closing direction upon initial closure of the passageway to said chamber, whereby upon movement of the auxiliary closure means by said second float means into an initial closing position whilst the said passageway is subjected to suction a reduced pressure is established in said passageway which moves the auxiliary closure means further in the closing direction until, upon completion of the available relative movement between the auxiliary closure means and the valve member, the latter becomes moved to open the passageway to atmosphere.

Claim 5

A valve according to claim 2, wherein the said auxiliary closure means comprises a radial plate which is at least partially flexible and resilient, is arranged for limited axial movement upon said valve member for cooperation with a flared throat of said passageway, and is directly mounted upon an annular float coaxial with said valve mEmber and arranged in said chamber.