GB2253893A - Flow regulating valve - Google Patents

Abstract

A pressure regulator for fluid flow has a manually operable member (40) enabling control of the regulated pressure of fluid flowing through the regulator and an adjustment member (23) having an end wall (26) which bears on a flange (17) of the manually operable member (40), the adjustment means (23) being adapted to pre-set the manually operable member to a position in which at least a predetermined minimum flow of fluid through the regulator is always possible. Such a regulator has been found to be beneficial in use with fluid flow circuits with instantaneous water heaters to ensure that where the heaters are activated there is always sufficient water flowing through the heater to prevent over heating or other damage. <IMAGE>

Description

Title: "Flow Regulating Valve" Description of the Invention The present invention relates to a valve for controlling fluid and is primarily concerned with a valve, hereinafter referred to as a regulating valve, which may be of a form wherein fluid passing through the valve influences a movable member situated in the valve in a manner so that pressure at the outlet of the valve is maintained reasonably constant irrespective of fluctuation in certain limits of pressure at the inlet or the valve may be of a form known as a governor which is instrumental through the action of a spring loaded diaphragm to maintain a constant volume of flow irrespective of fluctuations in inlet pressure to a valve.

A pressure regulating valve is described in British patent No. 2,192,970B in which a valve includes an addition to its pressure regulating features, a manually operable member which enables the valve to be turned off and in which also the manually operable member enables the volume of fluid flowing through the valve to be adjusted.

British patent application No. 9003231.9 describes a water governor having a similar type of on/off facility and flow regulation means.

Both the above mentioned flow regulators have been found to be suitable for use with such devices as instantaneous electrical water heaters where the fluid flow is critical and, when used in electric showers for example, when it is desired to maintain a constant water temperature, it is imperative that the water flow is carefully controlled irrespective of input pressure fluctuations which are very common in domestic water supply installations, if for example another tap or other water using appliance is turned on in the same circuit.

Whereas both types of valve are extremely useful a problem has arisen in that, in particular with instantaneous electrical heaters, in order to energise the heater it is of course essential that there is a predetermined minimum flow of fluid over the heating element. The heating element is normally of considerable power in order to obtain a reasonable rise in temperature of the water flowing past and hence if an adequate supply of water is not ensured, there is the risk that the element will be overheated which may cause it to burn out or cause other damage.

One obvious solution to the problem is to provide a water regulator or governor that has a resiliently biased diaphragm which ensures that there is always a limited supply of fluid flowing through the valve. This however is not so easy since the action of the diaphragm depends on the resilient force applied thereto and hence on the nature of the spring and apparently identical springs have been found not to provide the same resilient force.

It is an object of the present invention to provide a flow regulator that overcomes or minimises the problems mentioned above.

According to one aspect of the present invention, we provide a fluid flow regulator having an inlet and an outlet, a movable member having first resilient biasing means acting thereon, said movable member being adapted to be acted upon by fluid flowing from the inlet to the outlet in a manner to influence the flow of fluid through the valve and wherein adjustment means are provided operable to influence the force exerted by the resilient means such that when said valve is operative so that fluid can flow from the inlet to the outlet, a predetermined flow is ensured at the desired set position of the valve due to the setting of said adjustment means.

Preferably said setting may be a pre-set minimum flow at a minimum "on" position of said valve. In the case of a valve having no "off' position then the adjustment means may be set to achieve a minimum flow and/or a predetermined flow at a predetermined "on" position.

Preferably said regulating means also comprises a manually adjustable member which enables fluid flow through said valve to be regulated and irrespective of said regulation by said manually operable member, said minimum fluid flow is always achieved once the on/off facility is in its "on" position.

Preferably said adjuster means comprises a threaded member adapted to pre-tension the resilient means acting on the movable member.

Conveniently, said threaded member may comprise a sleeve-like member adapted for threaded engagement with the body of the valve and self adapted to bear directly or indirectly on a bearing member abutting one end of a spring, the other end of which acts on said movable member.

In the case of a flow regulating valve that does not have any on/off facility, said adjustment means may be adjusted to ensure that the resilient member provides the correct force to achieve at all times at least the desired minimum flow.

In the case of a flow regulating member that has an on/off facility, quite clearly when the regulating member is in an "off' position, such minimum flow cannot be achieved otherwise the valve will not be effective to turn off the fluid flow.

In such a situation, it will be understood that the minimum flow will be required under certain circumstances, for example during energisation of an instantaneous electrical heater. It is envisaged that the manually operable member that controls the fluid flow through the valve may itself be responsible for or at least initiate activation of said electrical heater and it is envisaged that there will be an "off' position and an "on" position and in the case where the movable member is a rotatable member, the distance between said on and off positions may be a set number of degrees and when said movable member has reached said "on" position, the electrical heater may be activated and in that position the adjustment means will have been adjusted to ensure that said minimum flow requirement is maintained by said regulating valve.

Thus, even in the case where the valve has an on/off facility, said adjustment means may usefully be included to ensure that the valve, particularly when used in combination with an instantaneous electrical heater, operates safely.

The adjustment means has been found to be of great benefit particularly where a manually operable regulating means is included and a relatively course adjustment is employed so that the angular movement between an "off" position and a fully "on" position is not greater than 3600 and in some cases considerably less.

This has practical benefit as far as display means are concerned or visual indication of the adjustment or relative position of the fluid flow control means.

One embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawing wherein: FIGURE 1 illustrates a cross-section of a governor embodying the adjustment means of the present invention.

Referring to Figure 1, the governor shown therein comprises a body in the form of two parts a lower part 10 and an upper part 20.

Each body part may be formed from any suitable material e.g. a metallic material a die casting or may be formed totally or in part in a plastics material and may for example comprise a plastics moulding.

The two body parts 10 and 20 are threadedly connected together.

The lower body part 10 is formed with an inlet 11 which communicates with a passage 12 which in turn communicates into an annular diaphragm chamber 13. An outlet passage 14 extends from the diaphragm chamber 13 at one side thereof and leads into an outlet port 15.

The diaphragm chamber 13 is closed by means of a diaphragm indicated generally at 30. The diaphragm consists of the rigid top plate 31 and a rigid lower plate 32. The top plate 31 has a boss 38 which extends through a central aperture in the diaphragm 34 and then an aperture in the rigid lower plate 32.

A nut 39 is threadably engaged with the boss 38 to secure the plates 31 and 32 an diaphragm 34 together.

The flexible diaphragm member 34 is located between the plates 31 and 32 and the diaphragm may be moulded from a suitable synthetic flexible material e.g. synthetic rubber and incorporates a annular convolution 35 and has at it periphery a bead 36. The bead 36 is received within a groove 16 formed in the body member 10 and the opposite face of the diaphragm member 34 is engaged peripherally by an annular washer 29 located in a rebate 28 formed in the top body part 20 of the casing.

Threadedly engaged with the hollow boss 21 is an adjustment member 23 which is in the form of a sleeve provided with an external helical thread 24 engageable with a complementary thread form on the boss 21, the adjustment part having a spanner or other tool engageable form 25.

The adjustment member 23 has a lower surface 26 which via threaded engagement with boss 21 can be brought into engagement with the upper surface of the flange 17 provided on an operating spindle 40.

The operating spindle 40 carries a collar 41 threadedly engaged therewith.

The collar 41 includes a pair of diametrically opposed lugs 42 which are slidably engaged in grooves 22 which extend axially with the boss 21. A spring 43 extends between the collar 41 and the top plate 31 of the diaphragm 30 so as to act in opposite direction to pressure exerted on the diaphragm by fluid in the chamber 13.

The operating member 40 may have formed at its upper end (not shown) a manually operable part such as a T-bar or other part which is eminently hand engageable to enable manual operation and rotation of the operating member 40.

Rotation of the operating member 40 will cause the collar 41 which is held against rotation by virtue of the lugs 42 located in grooves 22 to move axially and thereby adjust the compression of the spring 43. In this way the setting of the regulator may be varied.

It is desired that when in an "on" position, the valve permits a predetermined minimum amount of fluid to flow therethrough and the adjuster means 23 is moved by engagement of spanner or other tool on the flange 23, for example, to influence the minimum pressure applied by spring 43 to diaphragm 30 so that when the valve is in an "on" position, the desired minimum flow is achieved.

It will be appreciated that there will inevitably be a position between the valve "off' position and said "on" position in which said minimum flow would not be achieved which would not be the case in a flow regulating valve that did not have an "off" facility.

Where such an "off' facility is provided, such as in the valve illustrated, the manually operable means may be connected to display means that quite clearly show what position of the manually operable means indicates a rninimum "on" position in which said minimum flow is achieved.

Where said manually operable member may be operative to cause other operations to take place, for example energisation of an instantaneous electrical heater, the manually operable means may be operative to switcll on said electrical heater only when in the minimum "on" position.

It is envisaged that the threaded engagement 24 between the adjustment means 23 and the boss 21 will be relatively tight or otherwise other means may be employed to ensure that once pre-set the adjustment means stays in its desired position.

As can be seen the top plate 31 of the diaphragm 30 is received within the central recess 27 formed at the mouth of the hollow boss 21. A frusto conical configuration of helical spring 43 and the central recess 27 act together to properly locate the diaphragm 30.

The actual position of the diaphragm 30 will vary according to the compression of spring 43 and the water pressure existing in the diaphragm chamber 13. To effect regulation of pressure a valve assembly generally indicated at 50 is provided located within the bottom body part 10.

The valve assembly 50 comprises an insert 51 threadedly engaged with the bottom body part 10 and the valve member 60 is provided with a peripheral recess 62 which houses an o-ring 63 made of synthetic rubber or other suitable material, the o-ring 63 makes sealing engagement with a cylindrical surface 54 provided in the bottom body part 10.

The valve member 60 has secured thereto a sealing member 64 made from a relatively soft material e.g. a synthetic rubber which is capable of making sealing engagement with the annular lip 53 provided on insert 51.

The gap between the sealing member 64 and the annular lip 53 will affect the flow of fluid through the valve and the gap may be adjusted by rotation of the operating member 40 which in one rotational direction will cause the valve member 62 to be moved in a downwards direction thereby increasing the gap between sealing member 64 and annular lip 53.

In order to prevent movement of the valve member 60 being directly affected by pressure of fluid in the outlet port 15, a balancing passage 68 of the lateral port 69 is formed in the valve member to extend between the chamber 13 and counter-pressure chamber 65 situate below the valve member 62. In this way the pressure in the counter-pressure chamber 65 is maintained substantially equal to that which exists in the diaphragm chamber 13 of outlet port 15. Thus the net force acting on the valve member rising from the pressure of the outlet side of the governor is negligible since the valve member affords faces of substantially equal area at opposite ends.

In this way no significant net force arises on the valve member as a result of differential pressure between the inlet and outlet ports and the valve member 62 moves freely in response to any movement of the diaphragm 30.

The valve member 62 is provided with an upper rounded frusto conical nose 66 which engages in a corresponding recess 37 formed in the boss 38 carried by the diaphragm 30.

Operation of the operating member 40 in a direction to cause downward movement of the collar 41 will move the diaphragm 30 in a downwards direction through contact with the helical spring 43 hence the bearing part 38 will bear against a nose portion 66 of valve member 42 and increase the gap which exists between sealing members 64 and the lip 53. Since the diaphragm 30 will have its position resiliently controlled by spring 43 the device will maintain the water pressure at the outlet substantially constant.

Further biasing means in the form of the helical spring 59 also acts on valve member 62 in a direction urge the valve member 62 in an upwards direction and hence the sealing member 64 into engagement with lip 53.

In the situation where no pressure is being exerted onto the valve member 62 by a spring 43 i.e. there is no contact between nose portion 66 and corresponding surface 37 and bearing member 38 then the spring 59 will cause the sealing member 64 to come into contact with lip 53 effectively preventing flow of fluid from the inlet to the outlet.

It will be appreciated that since the governor illustrated in Figure 1 is of the balanced type then no or substantially no resultant fluid pressure acting on the valve member 62 and thus the governor may be caused to act as a valve by the application of fairly light pressure from biasing helical spring 59. The governor shown in the accompanying drawings therefore acts not only as a pressure regulating governor but also as an effective on/off valve which, because only a small force is required to maintain the valve in an off position it does not detrimentally affect the relatively soft material necessary to cause an effective seal between the valve member 62 and the seat 63.

The adjustment means 23 of the present invention is of considerable benefit in that it can be adjusted to ensure that a valve such as the valve above described can be suitably adjusted to ensure that when in an "on" position a minimum flow can be achieved subject to there being connection to a suitable supply, thus irrespective of the characteristics of the spring 43, the valve may be suitably adjusted to operate satisfactorily.

Such a facility eliminates the waste that would otherwise occur where valves are constructed and found because of variation in characteristics of the springs 43, they will not achieve the minimum flow requirements necessary or for that matter the minimum flow that they give is greater than is necessary.

The features disclosed in the foregoing description, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (10)

CLAIMS:

1. A fluid flow regulator having an inlet and an outlet, a movable member having first resilient biasing means acting thereon, said movable member being adapted to be acted upon by fluid flowing from the inlet to the outlet in a manner to influence the flow of fluid through the regulator and wherein adjustment means are provided operable to influence the force exerted by the resilient means such that when said regulator is operative so that fluid can flow from the inlet to the outlet, a predetermined flow is ensured at the desired set position of the regulator due to the setting of said adjustment means.

2. A fluid flow regulator according to Claim 1 wherein said adjustment means are set in a manner to ensure that when there is a fluid flow supply a predetermined minimum flow of fluid is ensured.

3. A fluid flow regulator according to Claim 1 wherein said adjustment means has at least two positions, an off position in which fluid flow through said regulator is prevented and an on position in which a predetermined minimum flow of fluid is ensured.

4. A fluid flow regulator according to any one of the preceding claims further comprising a manually operable member adjustable to enable fluid flow through said regulator to be regulated and wherein said regulator is operative such that irrespective of the adjusted position of said manually operable member said minimum fluid flow is always achieved at least when said regulator is in an on position.

5. A fluid flow regulator according to any one of the preceding claims wherein said adjustment means comprises a threaded member in threaded engagement with a body part of said regulator and adapted to pre-tension the resilient means acting on said movable member.

6. A fluid flow regulator according to Claim 5 wherein said threaded member comprises a sleeve-like member adapted for threaded engagement with the body of the regulator and adapted to bear directly or indirectly on a bearing member abutting one end of a spring, the other end of which acts on said movable member.

7. A fluid flow regulator according to Claim 6 wherein said sleeve-like member has means for preventing movement about its threaded axis with said body of the regulator after said adjustment has been effected.

8. A fluid flow regulator according to Claim 6 or Claim 7 wherein said manually operable member extends coaxially with and through said sleeve-like member and is provided with a flange which bears directly or indirectly on a bearing member abutting one end of a spring, the other end of which acts on said movable member and wherein said collar has an end surface adapted to engage said flange so as to limit movement thereof in one direction and hence effect the minimum force exerted by said spring.

9. A fluid flow regulator substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

10. A fluid flow regulator including any novel feature or novel combination of features disclosed herein and/or illustrated in the accompanying drawings.