Patent Application
20170002938
This invention relates to valves, for example, check valves, control valves and pressure relief valves.
Full port check valves, wherein the valve seat has substantially the same cross sectional area as the inlet and the outlet ports, are advantageous because they reduce fluid flow through the valve less than valves wherein the seat has a smaller cross sectional area than the inlet and outlet ports. However, full port check valves tend to be more complicated, as their housings are usually assembled from multiple pieces. Multiple piece housings are needed because check valves use pivoting clappers as their valve closure member, and clappers use face seals which seal against the valve seat. To sealingly engage the valve seat, face seals must match the size and shape of the valve seat. If the valve seat is equal in diameter (and hence in area) to the inlet and outlet ports it will not be possible to insert the clapper into the valve housing through the inlet or the outlet because a round clapper cannot pass through a round port of the same diameter. Hence the need for a housing that comes apart to permit installation of a clapper that is matched in size to the full port valve seat.
Advantages would be realized if a check valve (as well as other types of valves, such as control valves and pressure relief valves) were made having a single piece housing, made for example, by casting, machining or molding, so that it needed no assembly, such as bolting, brazing or welding of various parts to one another. However, prior art valves having a single piece housing have a clapper that is limited in size so that it may pass through the valve inlet or outlet for installation within the valve. The smaller clapper limits the cross sectional area of the valve seat, which must be smaller than the cross sectional area of the inlet and the outlet, resulting in greater resistance to fluid flow. There is clearly an opportunity to improve both the construction and performance of valves by developing a valve that uses a single piece housing yet does not suffer the known disadvantages of prior art valves.
The invention concerns a valve. In one example embodiment the valve comprises a single piece housing defining an inlet having an inlet inner diameter, an outlet having an outlet inner diameter, and a chamber positioned between the inlet and the outlet. A valve seat is positioned within the chamber between the inlet and the outlet. The valve seat defines an opening having a non-round cross sectional shape. A valve closing member is mounted within the chamber. The valve closing member has a non-round cross sectional shape. The valve closing member is movable between a closed position sealingly engaging the valve seat, and an open position out of engagement with the valve seat.
In this example the valve closing member has a major dimension and a minor dimension less than the major dimension. The major dimension is greater than or substantially equal to one of the inlet inner diameter and the outlet inner diameter. The minor dimension is smaller than one of the inlet inner diameter and the outlet inner diameter to permit the valve closing member to be inserted into the chamber through one of the inlet and the outlet.
In a particular example embodiment the valve closing member is pivotably mounted within the chamber. By way of example the valve closing member has a lozenge shape. In a further example the opening of the valve seat has a lozenge shape. In an example embodiment the major dimension of the valve closing member is greater than the inlet inner diameter. In a further example the major dimension of the valve closing member is greater than the outlet inner diameter. Also by way of example, the minor dimension of the valve closing member is smaller than the inlet inner diameter. In another example the minor dimension of the valve closing member is smaller than the outlet inner diameter. By way of example, at least one of the inlet and the outlet has a round cross sectional shape. In a specific example embodiment the valve comprises a check valve.
Another example embodiment of a valve according to the invention comprises a single piece housing defining an inlet having an inlet inner diameter, an outlet having an outlet inner diameter, and a chamber positioned between the inlet and the outlet. A valve seat is positioned within the chamber between the inlet and the outlet. The valve seat defines an opening having a non-round cross sectional shape. In this example only a single valve closing member is mounted within the chamber. The single valve closing member has a non-round cross sectional shape.
By way of further example, the single valve closing member is movable between a closed position sealingly engaging the valve seat and an open position out of engagement with the valve seat. In another example the single valve closing member has a major dimension and a minor dimension less than the major dimension, the major dimension being greater than one of the inlet inner diameter and the outlet inner diameter, the minor dimension being smaller than one of the inlet inner diameter and the outlet inner diameter to permit the single valve closing member to be inserted into the chamber through one of the inlet and the outlet.
In a particular example embodiment the single valve closing member is pivotably mounted within the chamber. Also by way of example the single valve closing member has a lozenge shape. Additionally by way of example, the opening of the valve seat has a lozenge shape.
In one example embodiment, the inlet has a conical inner surface defining a minimum inlet inner diameter. In a further example, the outlet has a conical inner surface defining a minimum outlet inner diameter.
By way of example, the major dimension of the single valve closing member is greater than the minimum inlet inner diameter. Further by way of example, the major dimension of the single valve closing member is greater than the minimum outlet inner diameter. In another example embodiment, the minor dimension of the single valve closing member is smaller than the minimum inlet inner diameter. Further by way of example, the minor dimension of the single valve closing member is smaller than the minimum outlet inner diameter.
In a particular example embodiment, the valve comprises a check valve.
The invention also encompasses a method of assembling a valve closing member into a valve having a single piece housing defining an inlet, an outlet and a chamber therebetween, a valve seat being positioned within the chamber. One example method comprises:
A particular example method comprises inserting the valve closing member through the outlet into the chamber. An example method further comprises pivotably mounting the valve closing member within the chamber.
As shown in
Both the valve seat 22 and the valve closing member 24 have non round cross sectional shapes. The shapes are matched to one another to permit sealing engagement between them when the valve closing member is in the closed position. As shown in
As shown in
The dimensional relations between the inlet and outlet inner diameters 38 and 40 and the minor dimension 36 of the valve closing member 24 permit the use of a single piece housing 12 because installation of the valve closing member 24 into the chamber 18 may be effected by inserting the valve closing member into the chamber through either the inlet 14 or the outlet 16. Once positioned within the chamber 18 the valve closing member 24 may be manipulated to mount it on axle 26 for pivoting motion relative to the valve seat 22. Once assembly of the valve closing member 24 is complete (along with other minor components such as the drain plug 20) the valve is 10 is ready for installation in a piping network.
The use of the non-round valve closing member 24 in combination with the single piece housing 12 provides at least two advantages for valves such as check valves, control valves and pressure relief valves. First, it permits a simpler valve design with fewer piece parts; second, it permits the use of a valve seat having an opening larger in cross sectional area than would otherwise be permitted with a round valve closing member. It is thus expected that valves according to the invention will achieve lower head loss than similarly sized prior art valves, thereby requiring smaller pumps for a more efficient and economical fluid transport system.
