Fluid handling – Back flow prevention by vacuum breaking – Air vent in liquid flow line
Patent
1993-08-25
1996-07-09
Michalsky, Gerald A.
Fluid handling
Back flow prevention by vacuum breaking
Air vent in liquid flow line
137217, F16K 2400, E03C 110
Patent
active
055335462
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a valve assembly for prevention of backflow in taps and faucets generally and which is attachable to the tap or faucet.
The invention will be described by way of example with reference to stop cocks but it should be appreciated that the invention is not limited to just such an application. The valve of the invention may be used in other ways also. For example the valve of the invention may be used in relation to globe valves which include inline stop cocks.
BACKGROUND ART
A normal stop cock valve tap consists of a body with an inlet, an outlet, a valve seat between the inlet and outlet, a spindle with a handle and a valve member movable by the handle to either cause it to seal against the seat or release it for movement away from the seat.
With such valves there is no protection against backflow and harmful substances can travel into the supply line and contaminate liquid in the supply line which may exit from that of other valves coupled to the line.
Backflow prevention devices are known and these are either fitted upstream or downstream of the valve. Where the valve is a standard stop cock, downstream backflow prevention devices may either be fitted directly to the outlet of the stop cock or in a line attached to the outlet. Such devices can readily be removed and for this reason are undesirable.
Backflow prevention devices mounted upstream of the stop cock require fitting by a skilled tradesman and are difficult to retrofit.
Reference may also be made to Australian specification 68314/90 which describes a tap having the same construction as a conventional stop cock as described above which also includes a backflow preventer. In this arrangement an operator is connected to a valve closure member which opens and closes the flow passage between inlet and outlet. The backflow preventer comprises a tubular body having a flow path therethrough which is connected to the outlet and a non-return valve fitted within the tubular body. A vacuum break opening is formed in a wall of the tubular body and there is also provided a diaphragm to open the opening and permit communication between the atmosphere and the flow path when the pressure within the flow path is less than ambient pressure.
In Australian specification 69869/91 (EP441151) there is described a mixer tap with a shower head attachment which incorporates a venting device for preventing water from being drawn back via a hose connection between a housing of the mixer tap and shower head. There is provided a pair of valves inserted in a water feed for the shower head wherein each valve has a movable valve element displaced between two opposing valve seats respectively associated with a vent opening and a flow opening for the water feed. Each valve element is biased towards the valve seat associated with the water feed opening.
Australian specification 59050/90 describes a backflow preventer valve adopted to be fitted to a conventional tap or stopcock as described above. The valve has an inlet and outlet connected by one or more passages and an annular main valve member formed of flexible material which may move between a closed position when there is back flow through the valve and an open position when there is normal flow of liquid from upstream to downstream. One or more discharge passages connect to interior of the valve body to atmosphere on the downstream side of the main valve member. A spring loaded valve actuator closes the main valve member when there is a back flow from the downstream side and also closes the discharge passage(s) when there is a normal flow from upstream to downstream.
U.S. Pat. No. 4,969,483 describes an anti-siphon assembly especially for a shower mechanism which has an automatic flexible one way valve associated with a cover of a housing of the anti-siphon assembly. The cover has air intakes controlled by the one way valve. The valve has an elastic lip and remains closed while the pressure in a control valve of the shower mechanism is above atmospheric but opens as soon as the press
REFERENCES:
patent: 2133804 (1938-10-01), Brooks
patent: 2259984 (1941-10-01), Anderson
patent: 3416556 (1968-12-01), Nelson
patent: 3470898 (1969-10-01), Langdon
patent: 3713457 (1973-01-01), McInnis et al.
patent: 3727630 (1973-04-01), McInnis
patent: 3929150 (1975-12-01), Flinner
Michalsky Gerald A.
Valvtec Pty Limited
LandOfFree
Assembly for prevention of backflow in valves does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Assembly for prevention of backflow in valves, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Assembly for prevention of backflow in valves will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1861005