Fluid handling – Line condition change responsive valves – Direct response valves
Patent
1992-09-11
1993-10-12
Nilson, Robert G.
Fluid handling
Line condition change responsive valves
Direct response valves
137469, 1375395, F16K 1506
Patent
active
052516644
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a check valve with means that quiet noise that might be generated by a pulsating flow past the valve.
State of the Art
A check valve has a valve head which is urged against a valve seat by a spring. The known valve head is spherical. A flange across the path of flow is formed downstream of the valve head. There are a large number of solutions for preventing noise when valve heads in check valves or cock-operated valves close against a valve seat.
In Swedish patent SE,C, 139 389, a solution is disclosed for preventing the thin film of liquid, which passes between the valve head and the seat in an almost closed position, from causing a whistling noise. By virtue of the fact that the throughflow channel, upstream of the valve seat, is designed with axially running grooves in the channel wall, disintegration of the film of liquid is brought about before it passes the valve head. Consequently, the valve head can be kept in a minimal opening position without a passing film of liquid causing a whistling noise.
In American patent U.S. Pat. No. 3,735,777, progressive throttling of the flow in a check valve is brought about when the flow exceeds a given value. Downstream of the ordinary check valve seat, there is in this case a second valve seat, against which the valve head closes, counter to the action of a check valve spring, when the flow becomes too great. By virtue of the fact that the channel walls taper towards this second seat and are formed with grooves running in the direction of flow with decreasing flow cross-section, progressive throttling is brought about. This damps the speed of the valve head towards the closing position so that a fully developed flow is not closed off abruptly.
A solution for preventing clattering check valves is shown in American patent U.S. Pat. No. 3,782,412. In this case, a cylindrical valve head runs in a narrow circular throughflow channel so that only a narrow gap is formed between the valve head and the channel. By virtue of the fact that the cylindrical valve head is plane-machined on its outer surface in only three places of four generatrices distributed evenly over the circumference, a lateral force is brought about on the valve head towards the channel wall in the event of developed flow. Consequently, the valve head adheres against the wall so that small flow fluctuations do not cause the valve head to strike down against the valve seat.
A check valve which to a certain extent reduces the noise which is brought about when the check valve strikes against the seat is shown in American patent U.S. Pat. No. 3,532,115. In this case, the valve head has a first sealing body in the form of a rounded elastic valve head which allows deformation of the valve head until a more rigid collar downstream on the valve head comes into contact around the valve seat.
Another check valve, which in the first instance is intended for intermittent flow with short opening times of high frequency, is shown in German Patent Application DE,A,36 12 393. In order to give the valve head improved control in the throughflow channel so that the valve head is centred against the seat in the sealing position, the valve head is in this case designed with recesses, evenly distributed around the circumference, upstream of the parts on the valve head which come into contact against the seat.
The previously known check valves do not, however, have any constructive measures for damping the movement of the valve head down towards the seat apart from the damping which is afforded by the throttling between the valve head and the seat. As the valve head of a check valve is conventionally designed as a sphere or hemisphere in order to reduce the flow resistance over the check valve, this means that a small flow fluctuation can cause a rapid movement of the valve head towards the seat. The valve head can to a certain extent be made elastic and shock-absorbing, but such a design does not reduce the speed of the valve head upon movement towards the seat, as a result of which noise can still
REFERENCES:
patent: 177564 (1876-05-01), Rudd
patent: 2440027 (1948-04-01), Stoyke
patent: 2804825 (1957-09-01), Mansfield
patent: 2860662 (1958-11-01), Gres
patent: 3055388 (1962-09-01), Tebb
patent: 3532115 (1970-10-01), Hodil, Jr.
patent: 3735777 (1973-05-01), Katzer et al.
patent: 3782412 (1974-01-01), Darash
patent: 4446886 (1984-05-01), Taylor et al.
patent: 4566486 (1986-01-01), Taylor
Derwent Patent Abstract for U.S. Patent No. 4,964,391; Oct. 1990.
Arvidsson Hans
Bjerendal Gert
Nilson Robert G.
Saab Automobile Aktiebolag
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