WO2011086339A1

WO2011086339A1 - Hydrant valve

Info

Publication number: WO2011086339A1
Application number: PCT/GB2010/002319
Authority: WO
Inventors: Paul Clark; Brian Rex
Original assignee: Crane Limited
Priority date: 2009-12-30
Filing date: 2010-12-23
Publication date: 2011-07-21
Also published as: GB2476656A; GB0922683D0

Abstract

A hydrant comprising; a hollow body (1) enclosing a valve, the hollow body terminating at one end in an inlet flange (2) configured for connection to a riser pipe, and at an opposing end in an outlet (3) positioned axially directly above the inlet providing an unobstructed first bore from inlet to outlet when the valve is opened, a second bore connecting with the first bore receiving a shaft (6) which carries an operating means for operating opening and closure of the valve through axial or rotational movement of the shaft, the valve mechanism comprising a plug (10) configured to sit onto a seat (11) provided around the body wall defining the first bore, a fixed hinged linkage (7,9 ) linking the plug with the shaft configured such that on axial movement of the shaft or mount carried thereon, the plug is caused to be moved between a position where it is fully engaged with the seat and a position where the bore is unobstructed.

Description

HYDRANT VALVE

The present invention relates to an improved valve arrangement for use in a hydrant such as but not strictly limited to a fire hydrant.

A hydrant as referred to herein is any outlet for a given fluid from a mains supply. Typically a hydrant is provided in the form of a branch outlet pipe extending from the mains supply pipe and terminating in a valve which can be operated to release fluid from the supply. A common example is a fire hydrant, fire hydrants typically consist of a valve which is located in the ground and connected to the main via a riser pipe.

The valves used in the prior art are generally constructed in accordance with the local industry standards. In the UK, the standard valve includes a mechanism which has a drive spindle directly above the inlet of the valve for activating the stopper. The outlet, to which is connected a standard threaded outlet sometimes referred to as "London outlet" for connecting with a fire hose is offset to the inlet by typically 100mm or more. Consequently, when the valve stopper is opened, the fluid (water in the case of a fire hydrant) is forced to follow the path of an "S" bend to the outlet.

This prior art valve design is most suitable for fire service access to the mains water. However, recently such hydrants have been required to be put to other uses, for example by water companies to access the main for such activities as (but not strictly limited to), cleaning, camera access, mains stopping, launching repair medium, monitoring water quality and pipe conditions and other new initiatives that reduce the need to otherwise dig holes to access mains pipes. It will be appreciated that digging for access to the mains has significant disadvantages to the public such as but not limited to disruption to traffic and pedestrian throughways causing potential safety hazards and also to the utilities service in having a considerable associated cost and lead time. As mentioned above the current fire hydrant valve design imposes a direct obstruction on the axis of the inlet when the valve stopper is opened, causes any inserted service to follow the S bend which is very restrictive and in many instances impossible.

Through bore valves are known to be used in various forms, for example; eccentric plug valves, plug valves, gate and plate valves. These are known to have been adapted for and used in hydrant applications. Although solving the practical problem of access direct to the main on the axis of the inlet with no diversion, these valve types do however introduce certain disadvantages in normal use. Some recognised disadvantages include; excessive cost, compromise of hydrant integrity, safety issues in use, susceptibility to freezing temperatures, poor operator feel during operation and increased potential for leakage and use excessive space in the hydrant chamber.

The present invention aims substantially to overcome the disadvantages of the known hydrant valve arrangements and those associated with the adaptation of through bore valves.

In accordance with the present invention there is provided a hydrant comprising; a hollow body enclosing a valve, the hollow body terminating at one end in an inlet flange configured for connection to a riser pipe, and at an opposing end in an outlet positioned axially directly above the inlet providing an unobstructed first bore from inlet to outlet when the valve is opened, a second bore connecting with the first bore receiving a shaft which carries an operating means for operating opening and closure of the valve through axial or rotational movement of the shaft, the valve mechanism comprising a plug configured to sit onto a seat provided around the body wall defining the first bore, a fixed hinged linkage linking the plug with the shaft configured such that on axial movement of the shaft or mount carried thereon, the plug is caused to be moved between a position where it is fully engaged with the seat and a position where the bore is unobstructed. Desirably, the seat is located in a plane which is not perpendicular to but is angled to the axis of the first bore.

Desirably the second bore is positioned in parallel alignment with the first bore.

Optionally, the hinged linkage includes a guide means which cooperates with a fixed protrusion on the shaft whereby when the shaft is moved; the guide follows the protrusion and forces movement of the plug. In one specific embodiment, the fixed protrusion is the axle of a stem nut and the guide means is a slider into which the stem nut locates. In an alternative embodiment the guide means may consist of a male guide which is located in sliders in a stem nut fixedly located on the shaft. Most desirably two or more guide means are present.

Desirably the distance between the axis of the shaft and the axis of the hinge is equal to or greater than the distance from the axis of the hinge to the centre of the plug.

Optionally, the guide may be configured to follow an arch or series of arches or non uniform shapes.

In another option, the fixed hinge linkage links with the shaft by means of an articulating linkage with a fixed pivot point provided on the shaft.

The hydrant is generally made fluid tight by the inclusion of seals around the shaft and at the valve plug /seat interface. For example, a gasket is provided at the interface. The contact surface profile of the gasket seat is preferably of a rimmed disc which is housed within a rimmed disc of the plug face.

Desirably a sump is provided in the body into which water draining off the inclined seat can flow harmlessly. The hydrant may further include a shaped annular recess undercut beneath the seat at the inlet flange bore to act as a receptacle for an additional, temporary and separate stopper which can be engaged for the safe maintenance of the valve should there be need for replacement of internal mechanism whilst the mains is in operation.

Some embodiments of the invention will now be better described with reference to the accompanying drawings in which;

Figure 1 illustrates external views of a first embodiment of the hydrant of the invention

Figures 2a) and 2b) illustrate in cross section a first embodiment of the invention with the valve in both an open and closed configuration

Figures 3a) and 3b) illustrate in cross section a second embodiment of the invention with the valve in both an open and closed configuration.

Figure 4 illustrates an embodiment of the claimed invention in situ connected to a mains supply ready for use.

Figure 1 illustrates an external view of the proposed hydrants. As shown, there is a hydrant generally referred to as (1), having a flanged (5) inlet end (2) and an outlet (3) in axial alignment with the inlet (2). Distanced from an axis defined by the inlet (2) and outlet (3) is an operating mechanism of which can be seen an operating means (4) for opening the valve (not shown) inside the body (1).

Figure 2 shows a hydrant in cross section. The hydrant body (1) consists of an inlet flange (2) suitable for connection to a standard riser pipe from the pipe main (not shown). An outlet (3) onto which a standard hose fitting may be attached is axially directly above the inlet so that in the valve open position there is an unobstructed bore from the inlet (2) to the outlet (3). Parallel to the inlet / outlet axis and distally positioned approx 100mm or more is the axis for the open closure spindle or stem (referred to in claims generally as a shaft) (6).

The valve mechanism consists of a plug (10) that is designed to sit onto a seat (11) around the inner wall of the valve body (1) which defines a first bore extending from the inlet (2) to the outlet (3). The seat plane can be perpendicular to the axis of the first bore but in the embodiment shown is inclined at an angle.

The plug has at one edge an integral hinge (9) which locates into the side walls of the hydrant body (1) defining the valve bore. This can be achieved either directly or indirectly using bushes that might fixedly locate in to the valve bore wall or are alternatively dove tailed into suitable sliders oriented along a vertical plane accessed from the top of the valve.

From the hinge (9) and extending away from the plug (10) are sliders (7) into which are located axles of a stem nut (8).

In another version (not shown) the plug may consist of male guides which are located in sliders in the stem nut. The stem nut is threaded onto a stem which itself is located directly or within bushes in the valve body. The stem will be located such that it provides resistance to axial thrusts and is provided with suitable sealing means to prevent unwanted leakage around the stem to atmosphere.

The slider (7) can be arched or straight or following a non uniform curve or series of curves.

Preferably when the plug (10) is in its closed position the slider curve will be horizontal at the point in contact with the nut axle to transfer all to transfer all force axially through the stem (6) to avoid unnecessary side forces on the stem (6). Also the distance between the stem (6) axis and the hinge (9) axis should desirably be equal to or greater than the distance form the hinge (9) to the plug (10) center. In this way the force to close is less than the reaction force from the internal pressure acting on the plug (10).

In another alternative the slider (7) can be arched so as not to be horizontal in the closed position in order to afford a mechanical advantage in the closure of the plug (10).

The valve mechanism can be assembled using a minimum amount of machining by the use of a "building block" approach to the assembled components.

The valve body (1) is optionally split horizontally approximately along its middle to allow good access for assembly and coating and minimize the use of cores in the casting of the valve body thus reducing cost.

A gasket (not shown) will preferably be an integral part of the plug (10) mechanically fixed to, bonded to or integrally moulded as one with the plug (10). The contact surface profile of the gasket seat is preferably of a rimmed disc which is housed within a rimmed disc of the plug face (10). In operation the closed valve plug (10) will compress the gasket onto the seat (11) which when pressurized from the internal pressure will create a higher gasket pressure than initially formed. This enhances its sealing capability. As internal pressure is increased the sealing pressure of the gasket is also increased and always above the internal pressure. This ensures that the seal is always made once the gasket is just in contact with the seat (11).

To prevent freezing within the valve body above the seat and unwanted and unwanted contamination from stagnant water (where the hydrant is used in relation to a water mains and other contaminants from above ground sources a sump (12) is provided in the valve body which is the lowest part of the valve and where water which drains off the inclined seat (11) can flow harmlessly into. The drain plug (12a) for the valve is based on a large aperture to assist in the expulsion of the excess water when the valve is closed and any fine debris.

In the bore between the inlet flange (2) and the seat (11) there is a shaped annular recess undercut beneath the seat to act as a receptacle for an additional, temporary and separate stopper (not shown). This additional stopper can be introduced as a loose piece for the safe maintenance of the valve should there be need for replacement of internal mechanism during mains operation.

This separate stopper can be introduced into the valve using under pressure equipment attached the outlet of the valve and with the valve open, access can be made to this portion of the bore and the stopper manipulated into position for both sealing and self anchoring after which the under pressure equipment can be removed and the valve dismantled while the main is still in operation.

Once the valve is repaired it is reassembled and the under pressure equipment is replaced and the temporary stopper removed. The valve can then be shut using the normal operation and the valve put back into service.

Alternatively the provision for the temporary stopper can be made by two or more bayonet type engagements within the main portion of the body just above the plane of the plug seat which is either horizontal or inclined. The temporary stopper would then be provided with complimentary bayonet locators. During its application the temporary stopper is maneuvered into position locating the bayonets then rotating to both secure against being dislodged during pressure forces and also to tighten the engagement of the seal on the seat.

The main difference is the method in which the plug is attached to the stem nut. Figure 3 shows an alternative embodiment to that of Figure 2 but the embodiment shares many similarities in its design to that of Figure 2.

In the embodiment of Figure 3 the plug hinge (9) axis can be in a similar proximity to that of the embodiment shown in Figure 2 but the member connecting the plug (10) to the hinge (9) is provided with a further pivot axis onto which an articulating linkage (13) is attached which in turn is attached to the stem nut (8) on a pivot.

During operation the stem (6) is rotated causing (for example by means of a screw thread) an axially upward movement of the nut (8). This axial movement pulls the articulating linkage upwards and away from the valve seat (11) which in turn pulls the plug (10) away from the seat (11). The plug (10) which is pivoting about the hinge (9) will hinge away from the seat (11).

During closing of the valve seat the linkage (13) can be set so as to offer significant mechanical advantage.

Figure 4 shows an embodiment of the invention in situ in connection with a mains pipe as it might be installed ready for use. The inlet flange (5) connects with a flange (42) at the terminus of a riser pipe (40) leading from mains pipe 41.

The following advantages of the present invention have been identified over prior art hydrant designs.

• The proposed valve plugs create a similar feel to the standard hydrant for the operator

• The inclined valve seat arrangement ensures that the surface fluids are drained away to prevent contamination from, for example, stagnant water and freezing.

• The inclined valve seat reduces the distance the plug has to travel to leave the bore unobstructed. • The form and shape of the proposed plug guide in the first embodiment and the articulating linkage positions in the second embodiment can create the desired mechanical advantage for the valve operation

• In the first embodiment, the arch or shape of the proposed slider curves or in the second embodiment, the articulating linkage and hinge positions can determine the rate of opening which then controls the amount of fluid transferred during the opening phase. This can eliminate unwanted jets during the "cracking" of the seal.

• Proposed hinge bushes are a clearance fit in the body for improved coating coverage and ease of assembly.

• A large drain plug assists in the fast and efficient drainage and expulsion of fine debris.

• The gasket face in contact with the seat will create pressure responsive sealing enhancing the sealing capability of the gasket without the need for higher input torques on the stem.

• The narrow "backbone" to the valve body reduces the amount of obstruction to connecting the inlet flange bolts when installing.

• The valve is maintained as a dry valve evacuating any fluid from the body after use.

• Provision can conveniently be made for the safe maintenance of the valve by the introduction of the proposed undercut recess at the inlet flange bore for the reception of a temporary self anchoring stopper.

Claims

1. A hydrant comprising; a hollow body enclosing a valve, the hollow body terminating at one end in an inlet flange configured for connection to a riser pipe, and at an opposing end in an outlet positioned axially directly above the inlet providing an unobstructed first bore from inlet to outlet when the valve is opened, a second bore connecting with the first bore receiving a shaft which carries an operating means for operating opening and closure of the valve through axial or rotational movement of the shaft, the valve mechanism comprising a plug configured to sit onto a seat provided around the body wall defining the first bore, a fixed hinged linkage linking the plug with the shaft configured such that on axial movement of the shaft or mount carried thereon, the plug is caused to be moved between a position where it is fully engaged with the seat and a position where the bore is unobstructed.

2. A hydrant as claimed in claim 1 wherein the seat is located in a plane which is not perpendicular to but is angled to the axis of the first bore.

3. A hydrant as claimed in claim 1 or claim 2 wherein the second bore is positioned in parallel alignment with the first bore.

4. A hydrant as claimed in any of claims 1 to 3 wherein the hinged linkage includes a guide means which cooperates with a fixed protrusion on the shaft whereby when the shaft is moved; the protrusion follows the guide and forces movement of the plug.

5. A hydrant as claimed in claim 4 wherein the fixed protrusion is the axle of a stem nut and the guide means is a slider into which the stem nut locates.

6. A hydrant as claimed in claim 4 wherein the guide means consists of a male guide which is located in sliders in a stem nut fixedly located on the shaft.

7. A hydrant as claimed in any of claims 4 to 6 wherein two or more guide means are present.

8. A hydrant as claimed in any preceding claim wherein the distance between the axis of the shaft and the axis of the hinge is equal to or greater than the distance from the axis of the hinge to the centre of the plug.

9. A hydrant as claimed in any of 4 to 8 wherein the guide is configured to follow an arch.

10. A hydrant as claimed in any of claims 1 to 3 wherein the fixed hinge linkage links with the shaft by means of an articulating linkage with a fixed pivot point provided on the shaft.

11. A hydrant as claimed in any preceding claim including a gasket provided at the interface between the valve plug and valve seat and wherein the contact surface profile of the gasket is of a rimmed disc which is housed within a rimmed disc of the plug face.

12. A hydrant as claimed in any preceding claim further comprising a sump provided in the body positioned to collect fluid draining off the inclined seat.

13. A hydrant as claimed in any preceding claim further including a shaped annular recess undercut in the bore beneath the seat and extending to the inlet to act as a receptacle for an additional, temporary and separate stopper.