GB2393775A

GB2393775A - A hinged non-return valve

Info

Publication number: GB2393775A
Application number: GB0222972A
Authority: GB
Inventors: John Thorpe; Bryan Sanderson
Original assignee: Saint Gobain Pipelines PLC
Current assignee: Saint Gobain PAM UK Ltd
Priority date: 2002-10-04
Filing date: 2002-10-04
Publication date: 2004-04-07
Also published as: GB0222972D0

Abstract

A hydraulic check valve (10) includes a floating mounting. A hingeable valve door (17) is pivotably suspended via hinge arms (19a,19b). At their upper ends the hinge arms terminate in bosses (26). Each boss includes an elongate slot (27) in which a hinge pin (24) is both rotatably and slideably journalled. The elongate slots permit both pivoting and rectilinear movement of the valve door (17) towards and away from a valve seat (16) defined in a conduit (12). There may also be provided a mass (36, figure 6) for causing a moment to urge the valve door towards the valve seat.

Description

( 2393775

AN HYDRAULIC VALVE

This invention relates to an hydraulic valve that is suitable for use ea. in potable water supply pipes and sewage pipes, to control the flow of liquid s (especially water) therein.

In particular the invention concerns a type of hydraulic valve known as a check valve. Such a valve is also sometimes called a reflux valve or a non-

rctun valve.

Hydraulic check valves are typically located at intervals along water and sewage pipes. They are one-way valves, ie. they permit liquid flow along the pipes in a first direction; and prevent such flow in a reverse direction.

15 Hydraulic check valves are needed because flow along water and sewage pipes is generally intended to be unidirectional. There is a need to prevent unintended back-flow along such pipes, in order to mnimise the risks of flooding and sewage contamination.

: There is sometimes a need, however, to be able to hold an hydraulic check valve open to permit intentional back flushing of a water or sewage pipe ea.

with clean water or with chemicals.

known design of hydraulic valve (herein "a valve of the kind described") :: includes a hollow valve body including a through-going hydraulic conduit passing therethrough; a valve scat defined in the hydraulic conduit; and an openable and closeable valve door that when closed seals against the valve seat to close the hydraulic conduit in a liquid tight manner and when open allows the passage of liquid along the conduit.

In this known design the valve door is secured to a hinge leaf that is in turn

pvotably secured, typically but not exclusively by means of a journalled hinge pm, to the interior of the hollow valve body.

The hydraulic check valves are only successful if they are capable of s providing a liquid-tight seal (also known as a "drop-tight" seal) against a liquid test pressure such as 16 bar.

The creation of such a seal relies on accurate manufacture of mating surt'aces of the valve door and valve seat.

lithe valve bodies in the prior art are typically cast from iron, steel or bronze.

The valve doors typically are made from so-called "gunmetal". Valve doors on larger valves are often made of the same material as the valve bodies and l'urther comprise seat rings of gun metal.

It is possible to machine the valve seat of the valve body and a mating surface of the valve door, in order to provide for the necessary liquidtight seal. However such a liquid-tight seal only arises when the valve door aligns correctly with the valve seat.

2' Such alignment is clit'fieult to achieve reliably. This is principally because the hinge leaf is hingeably secured ea. by means of a cylindrical hinge pin that is rotatably received in a cylindrical recess in the east iron of the valve body. There is usually a lack of precision, in such a hinge, that is not 25 cheaply remedied.

(onsecluently it is the norm for the valve door and the hinge leaf to be separate items. The valve door and the hinge leaf are secured together by a coupling, including a set screw or bolt, that allows free play between the to coupled components ea. parallel to the longitudinal axis of the screw/bolt.

A rubber or other resiliently deformable bush stiffens and provides

rest I iency of the coupling.

( Such a coupling allows the valve door, if of an appropriate profile, to be self-centring relative to the valve seat thereby assuring good sealing of the 5 door and seat in use. On the other hand, however, the components of the "floating" coupling described hereinabove increase the complexity, cost and assembly time of the hydraulic valves.

Also it is necessary to provide interlocking parts, ea. a stud and recess lo fonned respectively in the hinge leaf and valve door, to prevent rotation of the valve door that could loosen or release entirely the set screw or bolt.

In some known hydraulic valve designs the hollow valve body includes an interior hinge chamber that communicates with the through-going hydraulic 15 conduit. The hinge pin and the cylindrical journal bearings therefor lie within the hinge chamber. The hinge leaf protrudes from the hinge chamber into the hydraulic conduit, with the valve door supported on the hinge leaf.

According to a first aspect of the invention a valve of the kind described to includes a hinge pivot secured to the hinge leaf and to the valve body so as to permit hinging movement of the valve door between its closed and open positions, wherein, (i) the hinge leaf and the valve door are rigidly secured one to another; and 25 (ii) the hinge pivot permits pivoting movement of the valve leaf and hence the valve door towards and away from the valve seat; and rectilinear movement of the hinge door toward and away from the valve seat. 30 'I'he rigid securing together of the hinge leaf and valve door advantageously simplifies the construction of the valve. For example, using this feature of

/ the invention allows the formation of the hinge leaf and valve door integrally with one another, ea. by casting. This considerably reduces assembly time.

The use of a hinge pivot that replicates the "floating" mounting previously provided by the set screw / bolt, bush and interlocking (antirotation) parts ingeniously increases the use to which the hinge pivot is put.

Preferably the valve of the invention includes a hinge chamber lo communicating with the hollow interior of the valve body and the hinge pivot is received in the hinge chamber. Even more preferably the hinge pivot includes at least one hinge pin secured to the hinge leaf; and the hinge chamber includes at least one journal bearing defined therein, the hinge pin being received in the journal bearing and the journal bearing permitting the said pivoting and rectilinear movement of the valve door towards and away from the valve seat.

These aspects of the construction of the hydraulic valve of the invention provide a reliable, economical "floating" pivot that allows the valve door to to seal correctly against the valve seat.

The preferred form of the journal bearing is an elongate slot whose axis of elongation extends away from a plane containing the valve seat, the hinge pin being slideably and rotatably received in the slot. this arrangement :5 conveniently pennits both rotational and rectilinear movement of the hinge pin in its journal bearing.

In practical embodiments the hydraulic valve of the invention preferably includes a pair of the journal bearings, respective, mutually spaced hinge lo pin portions being received in the respective journal bearings so as to permit the said pivoting and rectilinear movements of the valve door towards and

away from the valve scat. This allows for an even distribution of forces on either side of the hinge leaf. In such embodiments each said journal bearing includes an elongate slot whose axis of elongation extends away from a plane containing the valve seat and in which each associated hinge pin portion is slideably and rotatably received.

Some hydraulic valves are known in which a hinge pin supporting the valve door perforates a wall of the valve body (or of a hinge chamber secured thereon) and protrudes externally thereof. The hinge pin is rotatable in the lo perforation. A weight whose centre of mass is spaced from the pivot axis of the hinge pin confers a moment, on the hinge pin, that urges the valve door towards its closed position.

This arrangement is known as an "outside lever and weight" arrangement.

In a preferred embodiment the invention includes a hinge pin having secured thereto a mass causing a moment acting on the said hinge pin in use of the valve, the said hinge pin and the valve door being so interconnected that the biassing of the said hinge pin urges the valve door towards the valve 20 seat.

This arrangement advantageously allows the inclusion of an outside lever and weight arrangement in the apparatus of the invention.

25 Conveniently the mass is rotatable, about an axis of a said hinge pin, relative to the valve door; and the mass and the valve door are interconnectable by a force transferring member that is fixed relative to the mass and moveable relative to the valve door, the force transferring member being engageable with the valve door to urge the valve door towards its so closed position. More preferably the valve door includes a circular plate; and the force transferring member is engageable with the contra of the thus s

defined circle.

The foregoing features ensure that the moment resulting from the presence of the outside lever and weight acts on the centre of the valve door, even 5 though the mass itself is offset to one side therefrom. This in turn means that there is no tendency for the moment to urge the valve door ott-centre relative to the valve seat. C'onscquently a good, drop- tight seal results.

In one embodiment of the invention the hinge pin perforates a wall of the lo hinge chamber; and the mass lies externally of the valve body. This conveniently allows use of the outside lever and weight as a handle, with which an operator may hold the valve door in its open position. This is useful when back-flushing the valve or a pipe run in which it is connected.

t5 In practical embodiments of the invention the valve door and the valve seat include mutually mateable sealing surfaces each selected from one of a resiliently deformable material; and a rigid metal. These combinations of sealing surfaces are commonly used in the hydraulic valve art.

Consequently the apparatus of the invention is advantageously useable in to most of the commonly encountered valve types encountered in the art.

There now follows a description of preferred embodiments of the invention,

by way of non-limiting example, with reference being made to the accompanying drawings in which: :5 Figure I is a plan view from above of an hydraulic valve according to the invention; Figure 2 is a section on line X-X of Figure 1; Figure 3 is a section on line Y-Y of Figure 1; Figure 4 is a partially sectioned view showing one form of valve so door to valve seat mating surface combination useable in the valve of the invention;

Figure 5 is a view similar to Figure 4 showing another mating surface combination; Figures 6 to 8 are views similar to Figures 1 to 3, showing an alternative embodiment of the invention including an outside lever and s weight arrangement.

Referring to the drawings an hydraulic valve 10 comprises a hollow valve body 11 formed ea. by casting from iron. The valve body could also be formed from cast steel or other alloys.

Valve body 11 includes a through-going hydraulic conduit 1 2 fonned therein. As best seen in Figures 1 and 2 the valve body 11 is essentially cylindrical Is and has formed at either end a flange 13 of per se known design. The purpose of each flange 13 is to permit bolting of the valve 10 in a per se known manner at either end to a corresponding flange (not shown) of an hydraulic pipe. Each flange 13 has formed therein a circular series of through-going eyes 14 for this purpose. Other end connections are known to in the art and may also be used.

Through-going conduit 12 is elongate. Its axis of elongation is essentially parallel to the major axis of the cylinder defined by housing 11, whereby when the valve 10 is connected in a pipe run the conduit 12 per se offers as minimal resistance or disruption to the flow of liquid along the conduit 12.

Typically the valve body assumes in use the generally horizontal orientation shown, although the valve body may also assume in use a generally vertical orientation with the flow of liquid being upwards so At the left hand end of valve 10 as shown in Figures I to 3 a portion 12a of the conduit 12 is inclined downwardly. This allows the valve 10 readily to

accommodate a valve seat 16 and a valve door 17, and ensures that the top of the cover is below the top of the flange.

[n the Figure 2 arrangement the valve seat 16 is an annulus of EN 1982 s C'Ci491K or EN 1982 CC'492K grade gun metal that is firmly fixed in a cylindrical recess 18 defined at the right hand end of inclined conduit portion 12a.

The right hand face 16a of valve seat 16 is machined or otherwise made flat, lo as is visible in Figure 2, to define a sealing surface.

Valve door 17 is openable and closeable, in a manner described in more detail below.

Is Valve door 17 is in essence a circular disc to which is secured, by virtue of being cast integrally therewith, a hinge leaf 19 in the form of respective arms 19a, 19b protruding in use upwardly from the disc as shown.

The left hand face of valve door 17 includes at least an annulus 21 that is 20 machined or otherwise made flat. The machined annulus 21 is mateablc with the machined t'ace 16a of the valve seat 16, whereby when the valve door 17 occupies its closed position as represented by solid lines in Figure 2 the rcspectve flat surfaces provide a drop-tight seal. This is especially so when hydraulic pressure in conduit 12 acts on the right hand side of valve as door 17 to urge the flat surfaces 16a, 21 into sealing engagemcut with one another. Valve door 17 is moveable between its closed and open positions by virtue of a hinge pivot arrangement 22 rigidly secured to the hinge leaf arms 19a, 30 I')b.

Hinge pivot 22 allows hinging of the hinge door in the directions represented by arrow A (Figure 2). It also permits rectilinear movement of the valve door 17, in the directions represented by arrow B. in a manner described below.

Valve body 11 as shown includes formed on its in use upper side a hollow, essentially cuboidal hinge chamber 23. The hollow interior of hinge chamber 23 communicates with the hollow conduit 12. Hinge pivot 22 lies within hinge chamber 23, with the hinge leaf arms 19a, 19b interconnecting lo hinge chamber 23 and conduit 12.

The hinge chamber 23 includes a top wall 23a and side walls 23b, 23c, 23d, 23e. Hinge pivot 22 includes an elongate, cylindrical hinge pin 24 that is secured in hinge chamber 23 lying perpendicular to the elongate axis of is conduit 12. Hinge pin 24 is so secured by virtue of its ends being firmly received, ea. by means of a friction fit, screw thread or similar arrangement, in opposed side walls 23b,23d of the hinge chamber 23.

Within hinge chamber 23 each hinge leaf arm 19a, l9b terminates in a 20 generally cylindrical boss 26. Hinge pin 24 is journalled at either end in a journal bearing that includes an oval-shaped slot 27 that perforates a respective said boss 26 in a direction generally parallel to hinge pin 24. The major axis of the oval shape defined in each slot 27 is generally parallel to the elongate axis of conduit 12.

The slots 27 are generally mutually parallel and essentially identical. Each slot is, as shown, somewhat longer and deeper than the diameter of the hinge pin 24, whereby the bosses 26 (and hence the hinge leaves 19a, l9b and the valve door 17) are pivotable about the hinge pin 24 towards and 30 away from the valve seat 16; and slideable, with the slots 27 and the hinge pin 24 moving in a rectilinear manner one relative to another, towards and

away from the valve seat 16.

As a consequence of this arrangement the valve door 17 is moveable as represented by arrows A and B. c i> Since there are two of the bosses 26 that journal the hinge pin 24 at spaced locations, the valve door is also moveable in the directions of the arrows C' visible in Figure 1.

lo C'onsequently the valve door 17 is mounted in a "floating" manner that confers good sealing, while obviating the need for several components that are present in prior art arrangements.

Advantages of the hinge chamber 23, include: (i) the ability easily to replace or service the hinge pivot 22 without dismantling or disposing of the remainder of the valve 10 (by virtue of the hinge chamber 23 being defined as a housing that is distinct from the valve body 11 and releasably secured thereto by means of 20 bolts or set screws 28); and (it) the fact of the hinge pivot components 22 being located clear of the hydraulic conduit 12, whereby the service life of the hinge pivot is maximised and the hinge pivot causes minimal disruption to fluid 25 flow in the conduit 12.

Figure 4 shows in partially sectioned view a variant on the metal-tometal sealing arrangement of the valve seat 16 and valve door 17 shown in igloo e 2.

In Figure 4 the valve seat 1(, is essentially as shown in Figure 2, being an

I, annulus of BS EN 1982 CC491K or CC492K grade grin metal the right hand, mating surface 16a of which is machined or otherwise formed flat.

In figure 4 however the machined face 21 of door 17 is replaced by an 5 annulus 29 of an elastomeric material such as a natural or synthetic rubber.

Annuhs 2') is secured to door 17 in a location that defines a seal with flat face l(,a when the door 17 is closed. Annulus 29 has formed protruding therefrom an annular rib 31 that deforms on closing of door 17 to promote a lo good, drop-tight seal.

Figure 5 shows a variant of the Figure 4 arrangement. The separate annular metal insert defining valve seat 1(, is omitted from Figure 5. Instead Figure 5 includes a flat face 16a, against which rib 31 is sealable, formed in the 15 cast metal of the valve body 11.

Referring now to Figures 6 to 8 there is shown a second embodiment of the invention, incorporating an outside lever and weight assembly.

: In Figures 6 to 8 an hydraulic valve lea is similar to valve 10 of Figures I to 5, and is described with the aid of the same reference numerals Identifying similar components.

Valve lea differs from valve 10 in that hinge pin 24 includes an extension 25 24a at one end that perforates the side wall 23d of hinge chamber 23.

Extension 24a is supported in an annular bushing 32 where it perforates wall 23d.

so Extension 24a terminates in an arm 33 that extends perpendicular thereto.

In the embodiment shown arm 33 is secured by means of a conventional

( stud and nut assembly 34, although other fastening means are possible within the scope of the invention.

At its free end arm 33 has secured thereto a mass in the form of metal s cylinder 36. Cylinder 36 is secured to and 33 by a conventional nut and bolt combination 37, although other, equivalent f'astcnings lie within the scope of the invention.

The effect of mass 36 and arm 33 is to confer a net moment on hinge pin 24.

Hinge pin 24 includes rigidly secured thereto, mid-way between the bosses 26,a force-transferring member in the form of rigid finger 38 that extends downwardly towards the centrc of valve door 17. Since hinge pin 24 is rotatable relative to hinge door 17 the moment conferred by mass and arm is combination 36, 33 acts, via finger 38, on the centre of door 17 with which it is engageable. The right hand face of valve door 17 includes a protuberance 39 that the finger 38 engages.

Consequently the mass, arm and finger combination 36, 33, 38 tends in to normal use ofthe valve 10a to urge the door 17 towards its closed position.

On the other hand the mass 36 is chosen such that the normal flow of liquid from left to right along conduit 12is sufficient to open valve door 17.

as Figure 7 shows both the valve door 17 and mass 36 in their closed (solicl line) and open (<lotted line) positions.

The arm 33 is useable as a lever to permit manual opening of the valve door 17. This is achievable by virtue of the hinge pin 24 having protruding : transversely therefrom a cross pin 41 that engages the sides of the oval slot 27 after a predetermined degree of rotation of the hinge pin 24 relative to

the hinge leaf 19 has occurred. Conscqucntly the external a m 33 may be used to lift the valve door 17 to an open position and, as necessary, hold it open to permit back flushing of the valve. In the absence of the outside lever constituted by arm 33 such back flushing would tend to close the s valve door 17 onto the valve scat 16.

The variations in the valve seat 16 and door Lace 29 arrangements shown in Figures 4 and 5 are of course useable as desired in the embodiment of Figures 6 to 8.

Claims

/ 1. An hydraulic valve comprising: a hollow valve body; s a throughgoing hydraulic conduit passing through the hydraulic body; a valve seat defiecd in the hydraulic conduit; an openable and closeable valve door that when closed seals against the valve scat to close the hydraulic conduit in a drop-tight manner and lo when open allows the passage of liquid along the conduit; a hinge leaf secured to the hinge door; and a hinge pivot secured to the hinge leaf and to the valve body so as to permit hinging movement of the valve door between its closed and open positions, wherein, 15 (i) the hinge leaf and the valve door are rigidly secured one to another; and (ii) the hinge pivot permits pivoting movement of the valve leaf and hence the valve door towards and away from the valve seat; and rectilinear movement of the hinge door toward and away from the valve 20 seat.

2. An hydraulic valve according to Claim I including a hinge chamber

communicating with the hollow interior of the valve body and wherein the hinge pivot is received in the hinge chamber.
2.S
3. An hydraulic valve according to Claim 2, wherein the hinge pivot includes at least one hinge pin secured to the hinge leaf, and wherein the hinge chamber includes at least one journal bearing defined therein, the hinge pin being received in the journal bearing and the journal bearing :3o permitting the said pivoting and rectilinear movement of the valve door towards and away from the valve seat.

(
4. An hydraulic valve according to Claim 3 wherein the journal bearing includes an elongate slot whose axis of elongation extends away from a plane containing the valve seat, the hinge pin being slideably and rotatably 5 received in the slot.
5. An hydraulic valve according to Claim 3 or Claim 4 including a pair of the journal bearings, respective, mutually spaced hinge pin portions being received in the respective journal bearings so as to permit the said pivoting lo and rectilinear movements of the valve door towards and away from the valve scat.
(j. An hydraulic valve according to Claim 5 wherein each said journal bearing includes an elongate slot whose axis of elongation extends away from a plane containing the valve seat and in which each associated hinge pin portion is slideably and rotatably rcccived.
7. An hydraulic valve according to Claim 3 or any preceding claim dependent therefrom, a said hinge pin having secured thereto a mass go causing a moment acting on the said hinge pin in use of the valve, the said hinge pin and the valve door being so interconnected that the biassing of the said hinge pin urges the valve door towards the valve seat.

8. An hydraulic valve according to Claim 7 wherein the mass is :5 rotatable, about an axis of a said hinge pin, relative to the valve door; and wherein the mass and the valve door are interconnectable by a force transferring member that is fixed relative to the mass and moveable relative to the valve door, the force transferring member being engageable with the valve door to urge the valve door towards its closed position.

). An hydraulic valve according to Claim 8 wherein the valve door

includes a circular plate; and wherein the force transferring member is engageable with the centre of the thus-defined circle.

1(). An hydraulic valve according to any of Claims 7 to 9 wherein the 5 said hinge pin perforates a wall of the hinge chamber; and wherein the mass lies externally of the valve body.

11. An hydraulic valve according to any preceding claim wherein the valve door and the valve seat include mutually mateable sealing surfaces lo each selected from one of a resiliently deformable material; and a rigid metal. 12. An hydraulic valve generally as herein described, with reference to and/or as illustrated in the accompanying drawings.

Amendments to the claims have been filed as follows CLAIMS

1. An hydraulic valve comprising: a hollow valve body; 5 a through-going hydraulic conduit passing through the hydraulic body; a valve seat defined in the hydraulic conduit; an openable and closeable salve door that when closed seals against the valve seat to close the hydraulic conduit in a drop-tight manner and lo when open allows the passage of liquid along the conduit; a hinge leaf secured to the hinge door; and a hinge pivot secured to the hinge leaf and to the valve body so as to permit hinging movement of the valve door between its closed and open positions; 15 the hinge pivot including at least one hinge pin secured to the hinge leaf, a said hinge pin having secured thereto a mass causing a moment acting on the said hinge pin in use of the valve, wherein, (i) the hinge leaf and the valve door are rigidly secured one to another; 20 (ii) the hinge pivot permits pivoting movement of the valve leaf and hence the valve door towards and away from the valve seat; and rectilinear movement of the hinge door toward and away from the valve seat; (iii) the mass is rotatable, about an axis of the said hinge pin, 25 relative to the valve door; and (iv) the mass and the valve door are interconnectable by a force transferring member that is fixed relative to the mass and moveable relative to the valve door to urge the valve door towards its closed position.

30 2. An hydraulic valve according to Claim I including a hinge chamber communicating with the hollow interior of the valve body and wherein the

hinge pivot is received in the hinge chamDcr.

3. An hydraulic valve according to Claim 2, wherein the hinge chamber includes at least one journal bearing defined therein, the hinge pin being s received In the journal bearing and the journal bearing permitting the said pivoting and rectilinear movement of the valve door towards and away from the valve seat.

4. An hydraulic valve according to Claim 3 wherein the journal bearing lo includes an elongate slot whose axis of elongation extends away from a plane containing the valve scat, the hinge pin being slideably and rotatably received in the slot.

5. An hydraulic valve according to Claim 3 or Claim 4 including a pair Is of the journal bearings, respective, mutually spaced hinge pin portions being received in the respective journal bearings so as to permit the said pivoting and rectilinear movements of the valve door towards and away from the valve seat.

so 6. An hydraulic valve according to Claim 5 wherein each said journal bearing includes an elongate slot whose axis of elongation extends away from a plane containing the valve scat and in which each associated hinge pin portion is slideably and rotatably received.

as 7. An hydraulic valve according to any preceding claim wherein the valve door includes a circular plate; and wherein the force transferring mcmUcr is engageable with the centrc of the thus-dcfincd circle.
8. An hydraulic valve according to any preceding claim wherein the so said hinge pin perforates a wall of the hinge chamber; and wherein the mass lies externally of the valve body.
9. An hydraulic valve according to any preceding claim wherein the valve door and the valve seat include mutually mateable sealing surfaces each selected from one of a resiliently deformable material; and a rigid metal.
10. An hydraulic valve generally as herein described, with reference to andior as illustrated in Figures 4 to 8 of the accompanying drawings.