GB2064721A

GB2064721A - A check valve

Info

Publication number: GB2064721A
Application number: GB8032715A
Authority: GB
Original assignee: Crane Canada Co
Current assignee: Crane Canada Co
Priority date: 1979-12-06
Filing date: 1980-10-10
Publication date: 1981-06-17
Also published as: JPS6048670B2; ES8201709A1; GB2064721B; ES497307A0; NL8006643A; JPS56127866A; CA1140420A

Abstract

A check valve has a valve body with a chamber therein, an inlet in the valve body to the chamber and an outlet in the valve body from the chamber. A valve seat is provided on the inlet in the chamber, a valve closure member 16 within the chamber for seating on the valve seat to close the inlet, and means for mounting the closure member above the valve seat so it can move with both linear and curvilinear movement away from the valve seat to open the inlet. A support plate 17 for the closure member 16 includes a pair of laterally extending arms 28, 29 which rest on horizontal bearing surfaces defined by the valve body. A pin 30 extends through the valve body into a slot 31 in the plate 17 and permits limited linear movement of the closure member 16 prior to pivoting thereof. <IMAGE>

Description

SPECIFICATION A check valve This invention relates to an improved check valve. Check valves are well known. Generally they comprise a valve body having an inlet and an outlet with a valve closure member pivotably mounted within the valve. The valve is usually mounted in a line with the inlet and outlet aligned horizontally although some check valves are designed to have the inlet and outlet aligned at any angle between the horizontal and vertical. The closure member is adapted to seat on a valve seat within the valve body to close the inlet preventing reverse flow through the valve in the direction from the outlet to the inlet. The pivot for the closure member is usualiy located above the valve seat. The closure member can swing about the pivot, away from the valve seat, to open the inlet, allowing flow through the valve from the inlet to the outlet.Examples of check valves of the above general type are shown in the following U.S. Patents: 79,527; 846,317; 849,466; 922,262; 3,075,547; 3,144,045; 3,366,137 and 4,039,004.

The known check valves have several disadvantages however. The majority of the known valves have a top opening in the valve body for inserting the closure member into the valve from the top of the valve. Patents 79,527; 846,317 and 3,144,045 are representative of such valves. Such an opening however must be large enough to allow the valve closure member to be inserted. Thus a large closure cap is needed for the top opening. The cap and supporting boss in the valve body increase the weight of the valve and add to its manufacturing cost.

Many of the known check valves also employ pivot pins to pivotably mount the closure member above the valve seat. Patents 3,075,547 and 3,366,137 are representative of such valves. The use of pivot pins however generally requires another drilling operation in the housing for insertion of a pivot pin.

Another machining operation increases the cost of assembly.

All known check valves are made so that the valve closure members are mounted solely for pivoting movement toward or away from the valve seat. This makes it difficult to properly seat the valve closure member on the valve seat since an exact fit, and an exact mounting, is required. Close tolerances must be employed in the manufacture of the valve to provide the necessary fit, and no simple adjustment can be made to compensate for wear. In some cases resilient seats are provided to assist in compensating for manufacturing tolerances.

It is a purpose of the present invention to provide an improved check valve which provides good seating of the valve closure member on the valve seat without the requirement of low manufacturing tolerances or a resilient seat and which minimizes wear affecting the seat.

It is another purpose of the present invention to provide an improved check valve in which the valve closure member can be inserted through the outlet of the valve body without requiring a large top opening, thereby reducing weight and cost of the valve.

In accordance with the present invention, the improved check valve is provided with a simple valve closure member mounting whereby the valve closure member is merely suspended from support means and loosely retained on the support means by a small vertical restraining pin. The closure member pivots on the support means, about the vertical restraining pin, to open the valve. When the vertical pin is raised from a slot in the valve closure member, the valve closure member can be easily moved off the support means and removed from the valve body through the outlet of the valve.

The slot in the valve closure member for receiving the restraining pin is elongated and positioned therein so that when the valve closure member is seated on the valve face in the valve the pin is not located at either end of the slot. This permits the valve closure member to move both linearly and curvilinearly when opening or closing the inlet and thus permits good seating of the valve closure member on the valve seat, while at the same time accommodating wear.

The invention is particularly directed toward a check valve having a valve body defining a chamber therein, an inlet in the valve body to the chamber and an outlet in the valve body from the chamber. The inlet has a valve seat in the chamber and a valve closure member is provided within the chamber for seating on the valve seat to close the inlet. Means are provided for mounting the closure member above the valve seat so it can move with both linear and curvilinear movement away from the valve seat to open the inlet.

In a preferred embodiment, the means for mounting the closure member includes mounting surfaces within the valve body above the valve seat, and mounting members on a top portion of the valve closure member.

The valve closure member is suspended by the mounting members from the mounting surfaces. A slot is provided in the top portion of the valve closure member, and a removable restraining pin extends down from the valve body into the slot adapted to retain the valve closure member on the mounting surfaces.

An example of the invention will now be described in detail having reference to the accompanying drawings in which: Figure 1 is a side elevational view of one embodiment of the check valve according to the present invention; Figure 2 is an end elevational view of the check valve shown in Fig. 1 from the outlet side; Figure 3 is an end elevational view of the check valve shown in Fig. 1 from the inlet side; Figure 4 is a longitudinal cross-sectional view of the check valve shown in Fig. 1; Figure 5 is a cross-sectional view taken along line 5-5 of Fig. 4; Figure 6 is a cross-sectional view taken along line 6-6 of Fig. 4; Figure 7 is a perspective view of the valve closure member and restraining pin; and Figure 8 is a cross-sectional view of the support of the valve closure member taken along line 8-8 of Fig. 6.

The check valve of the present invention has a valve body 10 defining an interior chamber 11. An inlet 12 leads into the chamber 11 from one side of the valve body 10 and an outlet 1 3 leads out of the chamber 11 from the other side of the valve body 10. The inlet 1 2 and outlet 1 3 are axially aligned along a longitudinal axis and both have interior pipe threads 14. In the embodiment shown the inlet 12 and outlet 1 3 have the same diameters. The inlet 1 2 has a circular valve seat 1 5 where it enters the chamber 11.

The valve seat 1 5 is in a substantially perpendicular plane to the longitudinal axis of the inlet 1 2 and outlet 1 3.

A valve closure member 1 6 is mounted within the chamber 11. The closure member 1 6 has a main support plate 17, and a closure disc 18. The closure disc 1 8 is fastened at its center by a pin 20 to the lower end of the bottom portion of the support plate 1 7. The center pin 20 is a sliding fit in a hole in the support plate 1 7 to provide some axial movement between the disc 1 8 and the support plate 1 7. The closure disc 18 has a circular seating face 21, opposite support plate 1 7 which rests against valve seat 1 5 to close the inlet 1 2.

The valve closure member 1 6 is mounted within the chamber 11 above the valve seat 1 5 so that it can move with both linear and curvilinear movement away from the valve seat 1 5 to open the inlet 1 2. The mounting means include a pair of flat, spaced-apart support surfaces 22, 23 above the valve seat 1 5 within the chamber 11 as shown in Figs.

4 and 5. The support surfaces 22, 23 are spaced apart and extend substantially horizontally and perpendicular to the direction of flow through the valve. The support surfaces 22, 23 are formed by a pair of shoulders 24, extending inwardly into chamber 11 formed integrally with the side walls of the valve body 10 above the valve seat 15. The upper surfaces of the shoulders 24, form the flat support surfaces 22, 23. The valve body 10 has thickened portions 25 up-stream of the flat support surfaces 22, 23 to essentially eliminate the twisting action of the closure member 1 6 resting on the support surfaces 22, 23.

The main support plate 1 7 of the valve closure member 1 6 is suspended from the support surfaces 22, 23. The top portion 26 of support plate 1 7 is extended at an angle to the lower portion of the support plate 1 7 terminating in a flat cross-bar plate 27. The cross-bar plate 27 has mounting members in the form of flat pivot arms 28, 29 extending from each side to form a continuation of flat cross-bar 27. As may be seen in Figs. 7 and 8, the top portion 26 joins the flat cross bar plate 27 at its approximate center by means of a notch cut in the cross bar plate 27. The flat pivot arms 28, 29 are less than half the width of the cross bar plate 27 extending on the notched side of the plate 27.The flat pivot arms 28, 29 rest on top of support surfaces 22, 23 respectively to suspend the closure member 1 6 therefrom. The angle at which the top portion 26 of support plate 1 7 extends is such as to generally locate face 21 of disc 1 8 on the valve seat 1 5 beneath pivot arms 28, 29.

The main support plate 1 7 is retained on the support surfaces 22, 23 by a restraining pin 30 which fits into a slot 31 formed in the upper portion 26 of support plate 1 7. The pin 30 projects down into the chamber from one end of a bolt 32 which has a lower portion 32A larger in diameter than the restraining pin 30 to restrain the closure member 16 from rising up, thus causing the disc 1 8 to seat above the valve seat and not seal. The lower portion 32A also may in one embodiment act as a stop so that when the closure member 1 6 is pivoted to the open position, the top portion 26 comes to rest against the edge of the lower portion 32A instead of the center pin 20 resting against the inside surface of the valve body 10 as shown in Fig. 4.

The bolt 32 is screwed into a threaded bore 33 formed in a boss 34 at the top of the valve body 10 above shoulders 24. When the bolt 32 is screwed into bore 33 the pin 30 projects down into chamber 11 between shoulders 24, 25 and into the slot 31. The slot 31 extends on the top portion 26 of the support plate 1 7 in the longitudinal direction of the valve, perpendicular to the valve seat 15, and has rounded ends. The slot 31 extends generally from where the top portion 26 of support plate 1 7 meets the cross-bar 27 to about half-way down the length of the top portion 26. The top rounded end of the slot 31 is generally perpendicular to the flat surface of the cross-bar 27 and the lower end is generally perpendicular to the flat surface of the top portion 26 as shown in Fig. 8. The top rounded end of slot 31 is generally aligned with the upstream sides 35, 36 of the pivot arms 28, 29. The bottom edges of these sides 35, 36 form the pivot line for the valve closure member 1 6 as will be described.

Assembly of the valve is very simple. With the bolt 32 removed, the valve closure member 1 6 is simply inserted into the chamber 11 through outlet 1 3. The closure member 1 6 is hung by its pivot arms 28, 29 from the top of shoulders 22, 23 with disc 1 8 seated against valve seat 1 5. Bolt 32 is then screwed into bore 33 to locate its pin 30 loosely within slot 31. When the check valve is closed, with disc 1 8 flush against seat 15, the pin 30 is located within slot 31 spaced a short distance away from the top end of the slot 31.

When the valve is to be opened, the closure member 1 6 slides a short distance along the support surfaces 22, 23 toward the outlet 1 3 until the top end of the slot 31 abuts pin 30.

Pin 30 then initiates pivoting of the closure member, on its continued movement, about the pivot line at the bottom edges of pivot arm sides 35, 36 on the support surfaces 22, 23. Thus the valve closure member 1 6 has both linear and curvilinear movement when it opens and closes. This motion provides excellent seating of the valve while accommodating generous tolerances in fit in mounting the closure member. In addition, the elongated slot 31 accommodates for some wear between the valve seat 15 and disc face 21.

Axial movement also occurs when the center pin 20 supporting the disc 1 8 slides in the hole in the support plate 1 7. Thus there are provided two provisions for axial movement for the disc 18.

Locating the sides 35, 36 of the pivot arms 28, 29 in general alignment with the top rounded end of the slot 31 minimizes wear on pin 30 as the valve closure member 1 6 pivots about the bottom edges of the arms 28, 29 while restrained from further linear movement by the pin 30.

The cross-bar plate 27 is sized to fit loosely between the shoulders 24, as the closure member 1 6 pivots. The sides of the cross-bar plate 27 are slightly tapered to facilitate movement between the shoulders 24. The cross-bar plate 27 helps maintain the closure member 1 6 centered during pivoting movement.

In another embodiment, the closure member need not use narrow pivot arms 28, 29.

Instead, the cross bar plate can be rectangular without the two pivot arms. The closure member then pivots on the back edge of the cross bar plate. This configuraton is suitable for valves having only infrequent use because wear occurs as the rounded end of the slot of the support plate moves up the pin. In the configuration shown, there is little or no sliding movement between the support plate and the pin, so wear does not become a problem.

Claims

1. A check valve comprising: (a) a valve body defining a chamber therein; (b) an inlet in the valve body to the chamber and an outlet in the valve body from the chamber; (c) a valve seat on the inlet in the chamber; (d) a valve closure member within the chamber for seating on the valve seat to close the inlet; and (e) means for mounting the closure member above the valve seat so it can move with both linear and curvilinear movement away from the valve seat to open the inlet.

2. A check valve as claimed in claim 1 wherein the inlet and outlet are aligned along a longitudinal axis, the valve seat extending substantially perpendicular to the longitudinal axis, and the means for mounting the closure member includes two spaced apart flat mounting surfaces for the valve closure member above the valve seat within the chamber, the two mounting surfaces lying in the same plane substantially perpendicular to the valve seat.

3. The check valve as claimed in claim 2 wherein the means for mounting the closure member includes two flat mounting arms on a top portion of the valve closure member, extending in opposite directions from a central plate, the valve closure member suspended by the two mounting arms from the two mounting surfaces, and slidable therealong, with the two mounting arms extending generally perpendicular to the longitudinal axis of the valve body.

4. The check valve as claimed in claim 3 including a slot in the top portion of the valve closure member, the slot located between the two mounting arms and extending in a direction substantially parallel to the longjtudinal axis of the valve body, and a restraining pin within the chamber projecting down into the slot to retain the valve closure member on the two mounting surfaces, the pin initiating swinging movement of the closure member during opening.

5. The check valve as claimed in claim 4 wherein the restraining pin is attached to a bolt which is removably mounted in an opening in the top of the valve body.

6. The check valve as claimed in claim 4 wherein the valve closure member is sized to be inserted into the chamber through the outlet opening, to be suspended from the two mounting surfaces.

7. The check valve as claimed in claim 3 wherein the mounting surfaces are formed by shoulders extending inwardly into the chamber from the sides of the valve body, and the central plate on the top end of the valve closure fits loosely between the shoulders when the valve closure member pivots to loosely center the closure member.

8. The check valve as claimed in claim 1 wherein the means for mounting the closure member includes mounting surfaces within the valve body above the valve seat, mounting members on a top portion of the valve closure member suspended by the mounting members from the mounting surfaces, a slot in the top portion of the valve closure member, and a removable restraining pin extending down from the valve body into the slot adapted to retain the valve closure member on the mounting surfaces.

9. The check valve as claimed in claim 8 wherein the pin fits into the slot intermediate the ends of the slot when the valve is closed.

10. The check valve as claimed in claim 9 wherein the mounting surfaces are flat and extend generally perpendicular to the plane of the valve seat.

11. The check valve as claimed in claim 9 wherein the valve closure member has a size permitting its insertion into the chamber through the outlet in the valve body.

1 2. The check valve as claimed in claim 9 wherein the pin is attached to a bolt which is detachably mounted in an opening in the top of the valve body.

1 3. The check valve as claimed in claim 10 wherein the two mounting members comprise flat, laterally extending, arms the upstream side of the arms aligned with the upstream end of the slot in the valve closure member.

14. The check valve as claimed in claim 1 3 wherein the upstream side of the arms is in substantially the same plane as the valve seal on the inlet in the valve body.

1 5. A check valve substantially as described herein with reference to the accompanying drawings.