GB2076126A

GB2076126A - Improvements in valves

Info

Publication number: GB2076126A
Application number: GB8115364A
Authority: GB
Original assignee: Kiwong Pty Ltd
Current assignee: Kiwong Pty Ltd
Priority date: 1980-05-19
Filing date: 1981-05-19
Publication date: 1981-11-25
Also published as: GB2076126B

Abstract

A valve particularly adapted for use as a non-return valve in a fluid line having a metallic head (10) with a peripheral frusto-conical edge (11) adapted to contact a valve seat and a resilient portion (13) extending outwardly from the larger diameter portion of the frusto-conical edge (11), the peripheral part of the resilient portion (13) including a resilient skirt (14) the outer surface of which substantially continues the frusto- conical edge (11) of the valve, the skirt (14) being deformable to ensure a liquid tight seal with the valve seat. <IMAGE>

Description

SPECIFICATION Improvements in valves This invention relates to improvements in valves and, in particular, but not exclusively, to improvements in valves for use as check valves in a fluid line and, specifically, to check valves for use in petroleum lines.

In this specification we shall refer, generally, to the valves as being for use in petroleum lines without, in any way, limiting the generality of the use of the valve.

Check valves for use in petroleum lines which comprise a mushroom type valve having a metallic head having a peripheral frusto-conical seat and which have a resilient extension therefrom are known. In these valves, the valve head is adapted to absorb a fluid hammer effect on the valve when it is close to its seated position and the resilient portion makes the sealing contact with the seat in the valve body. Such valves have been, generally, satisfactory in use but there have been difficulties in providing valves for use in petroleum lines as the petrol tends to cause swelling of the resilient portion, thus obstructing the metallic head from being correctly iocated relative to the seat which mislocation, in turn, permits the fluid hammer effect to adversely effect the resilient portion.

Approaches have been taken to overcome this difficulty but they have not been wholely satisfactory. Thus, the valve needs to be replaced more regularly than would be desired and, it will be appreciated that if the valve is acting as a check valve adjacent to the outlet of a petrol tank, it can be most inconvenient and time consuming to gain access to the valve to permit its replacement.

According to the present invention there is provided a valve having a metallic head with a stem extending axially outwardly therefrom to control axial movement of the valve relative to a valve seal, the head having a peripheral frustoconical edge adapted to contact a valve seat, a resilient portion extending axially outwardly from the larger diameter portion of the frusto-conical edge, the peripheral portion including a resilient skirt, the outer surface of which substantially contains the frusto-conical edge of the valve, the skirt being deformable to ensure a liquid tight seal with the valve seat.

In order that the invention may be more readily understood, we shall describe, generally, two forms of valve member in relationship to the accompanying drawings, in which: Fig. 1 is a perspective view of the first form of the valve member; Fig. 2 is a plan view of the valve member of Fig. 1; Fig. 3 is a section along line 3-3 of Fig. 2; Fig. 4 is a plan view similar to that of Fig. 2 showing a second form of the valve; Fig. 5 is an elongated view of part of the valve of Fig. 4; and Fig. 6 is a section along line 6-6 of Fig. 5.

Each of the valve members illustrated has a head 10 which may be of a diameter substantially equal to the valve seat with which it is to be used and, normally, this diameter could vary between, say, 2 cm and 7 cm, but the size can vary beyond this range. The periphery 11 of the head is formed to provide a surface complementary with the valve seat and this may be a frusto-conical surface with the angle of the cone being approximately thirty degrees but, again, this angle can be varied widely depending upon the viscosity of the material with which the valve is to be used, and other parameters, to ensure accurate and rapid seating.

Extending axially of the head, and formed integrally therewith, there is a valve spindle 1 2 or stem and, depending upon the particular type of valve with which the valve member is to be associated, this stem may extend from the smaller or larger diameter side of the head but, for nonreturn valves, it is normally preferred that the stem extends from the smaller diameter side.

Associated with and connected to one side of the head, normally, and for description, the larger diameter side, there is a resilient member 13 which acts as a sealing member and which has a portion which is affixed to the head by means of a compatible adhesive or by an extension 1 7 from the head entering a complementarily shaped recess in the resilient member, which extension and recess are so formed that the member has to be deformed for interengagement, or directly formed on the head. The resilient member has, at its periphery a skirt 14 which extends, generally, in a frusto-conical manner and may be an extension of the cone of the head or may have a relieved portion adjacent the cone of the head and may, at its outer edge, have a diameter slightly greater than the extended diameter of the head at that position.This skirt 14 is integral with the main portion of the resilient member 13 and may have a thickness such as to be relatively stiff. However, in order to ensure a good seal with the valve seat, the skirt desirably has sufficient resilience at its area of contact with the valve seat so as to be able to accept variations in the periphery of the seat and, thus, to form an effective seal therewith.

In the second embodiment illustrated in Figs. 4 to 6 we provide, within the internal surface of the skirt, a plurality of grooves 1 5 which may be radiused and which may lie in axial planes but run along the internal surface 16 of the skirt or which may be more or less axial to provide variations in thickness along the length of the skirt. This arrangement is not illustrated.

The actual sizing and dimensions of these grooves can vary but, for a valve member having a diameter of approximately 4 cm with a skirt of a thickness of 0.2 cm we have found that a spacing of approximately 0.3 cm between grooves, which themselves have a width of 0.06 cm, and an equivalent depth, and which are radiused to a radius of 0.03 cm is suitable. These dimensions can be considered empirical in that, depending upon the density and thickness of the skirt, so it may be found that variations in these dimensions are desirable.

We have found that the valve of the invention provides improved properties over previously proposed valves. Firstly, the seal between the valve and the seat, under the weight of the valve and the liquid thereabove is effective. Secondly, variations in the resilient material over time, either because of wear or the action of the liquid concerned, is accommodated as are any variations in the seat itself. The valve is thus afforded an extended operating life.

Claims

1. A valve having a metallic head with a stem extending axially outwardly therefrom to control axial movement of the valve relative to a valve seal, the head having a peripheral frusto-conical edge adapted to contact a valve seat, a resilient portion extending axially outwardly from the larger diameter portion of the frusto-conical edge, the peripheral portion including a resilient skirt, the outer surface of which substantially continues the frusto-conical edge of the valve, the skirt being deformable to ensure a liquid tight seal with the valve seat.

2. A valve as claimed in claim 1 wherein the inner surface of the skirt is provided with a plurality of substantially axial grooves whereby the effective resilience can vary about the periphery of the skirt.

3. A valve as claimed in claim 2 wherein the grooves are parallel to the cone angle of the skirt.

4. A valve as claimed in claim 2 wherein the grooves are parallel to the axis of the valve.

5. A valve as claimed in any preceding claim wherein the valve stem extends from the smaller diameter portion of the valve body.

6. A valve substantially as hereinbefore described with reference to and as shown in Figures 1, 2 and 3 or in Figures 4, 5 and 6 of the accompanying drawings.