GB2177782A - Draining outlet - Google Patents

Abstract

A drain outlet for use in draining water from riser pipes consists of a hollow housing 102 which is screw- threadedly connectable to the lowermost point in the water supply system and has a closed end 111 in which are formed drainage holes 110. The housing is divided into upper and lower compartments by a rolling diaphragm 112 which includes a downwardly extending open-ended tubular portion 114 providing an aperture for communication between the upper and lower compartments. An adjustable valve member 116 projects upwardly from the end of the housing and includes a conical valve seat for engagement with the portion 114 of the diaphragm to form a watertight seal therebetween when the diaphragm is deformed by the action of water at a predetermined pressure. At lower pressures water drains passed the valve and out through the drainage holes. A tubular support member 130 may be provided to support the diaphragm when the latter is subjected to high water pressure. <IMAGE>

Description

SPECIFICATION Draining outlet The present invention relates to an automatic draining outlet for water supply lines.

A possible source of diseases such as legionnaires disease, has been identified in water, especially heated water, outlets which are used only intermittently and which, when not in use, remain filled or nearly filled with water. An example of such an outlet is the shower head fed by a riser pipe from a hot/cold water mixing valve. In such a system when the shower is not in use, i.e., when the mixing valve is turned off, water is retained in the riser pipe and also in the shower head itself. It is therefore desirable that in such systems means be provided for draining the pipe work.It is known to instal manually operated taps at the bottom of outlet riser pipes from hot/cold water mixing valves, for example; these have the disadvantage that users of the showers frequently forget to drain the pipe after use, therefore an automatic draining system operable when the water pressure to the outlet falls below a predetermined level is desirable.

We have now developed a simple and efficient automatic draining system for use in a water system in which water flows to an outlet up a riser pipe from a supply tap or valve located below the outlet.

In our system a draining valve is located at the bottom of a riser pipe on the outlet side of the supply tap or valve. The draining valve provides, in the open position, communication between the riser pipe and a waste water outlet via a valve outlet. The system relies on water pressure from the supply tap or valve to the riser pipe maintaining the drainage valve in the closed condition by engaging a closure member against the draining valve outlet and permitting the closure member, which may be spring loaded, to disengage from the outlet when the supply tap or valve is turned off and/or the pressure of water to the riser pipe falls below a predetermined level.

Accordingly, therefore, the present invention provides a drain outlet valve for use in water supply systems including riser pipes or the like and wherein the valve is connected to the lowermost point in the system, comprising a hollow housing having means for attachment to the said system to provide fluid flow communication therebetween, said housing including at least one chamber; a drainage hole formed in a lowermost portion of the housing to communicate with the chamber; a deformable closure member located in said housing to provide a watertight seal between the periphery thereof and the inner walls of the housing to provide upper and lower compartments to provide communication between said attachment means and the lowermost portion of said chamber; and adjustable valve means located in said housing and including a valve seat for co-operation with the aperture in the said closure member, whereby at a predetermined water supply pressure the said closure member is deformed to cause said aperture to engage said valve seat and provide a watertight seal therebetween, and at lower pressures a passageway is provided between said valve seat and said aperture to permit water from the system to flow through said attachment means into the housing and out tbrough the drainage hole communicating with the said chamber.

Preferably the closure member is a rolling diaphragm and includes a substantially centrally located open-ended tubular portion extending towards said valve means to provide said aperture.

Embodiments of the invention, designed for use with hot/cold water mixing valves supplying water to a static shower head through a riser pipe, will now be described with reference to the accompanying drawings in which: Fig. 1 is a cross section through one embodiment of a draining outlet according to the invention, and Fig. 2 is a cross section through a second embodiment of a draining outlet according to the invention.

Referring to fig. 1, a draining valve comprises an outlet connection 1 providing a passageway 8, that screw-threadedly engages a corresponding threaded portion at the bottom outlet of a hot/cold water mixing valve, washer 7 providing a watertight seal. A housing 2, defining a chamber 14, screw-threadedlyengages the open end of the outlet connection 1 and makes watertight connection therewith through "O" ring 6.

The lower end 9, of housing 2, includes a plurality of outlet holes 10 communicating with the chamber 14 of the housing. A cylindrically shaped valve member 4 screw-threadedly engages in a corresponding aperture formed in the base 9 of housing 2 and extends into chamber 14. The valve member 4 includes a conical valve seat 12 and, at the opposite end thereof, a slot 11 dimensioned to receive a screw driven blade, enables the extent to which the valve projects into chamber 14 to be adjusted by appropriate rotation of valve 4. A rolling diaphragm 3 has its outer edge engaged between the outlet connection 1 and the housing 2 to make a watertight connection therebetween to provide upper and lower compartments A and D.Diaphragm 3 has a central substantially cylindrical portion 13 extending downwardly into chamber 14 and includes, at the lower end thereof, an aperture 15 having a diameter less than the maximum diameter of the valve seat 12 to enable a watertight seal to be provided between compartments A and B. A spring 5 acts between the base 9 of the housing and the diaphragm 3 and has a tension lower than the outlet water pressure from the valve but greater than the maximum pressure exertable by the water contained in the riser pipe with the supply valve turned off.

In use, with the supply valve turned off, there is a clear- passageway between the diaphragm aperture 15 and the seat 12 of valve member 4 to permit water to pass from passageway 8 into compartment A of chamber 14 and out through compartment B and outlets 10. When the supply valve is opened the water pressure flowing into passageway 8 acts on the diaphragm 3 to urge the diaphragm towards valve member 4 and to cause aperture 15 to engage with seat 12 of valve member 4 and provide a watertight seal therebetween, spring 5 being compressed since the water pressure is greater than the spring tension.When the supply valve is turned off, however, the water pressure acting on diaphragm 3 is only that provided by the column of water in the riser pipe and since the tension in spring 5 is greater than that pressure it assists diaphragm 3 to move upwardly away from valve member 4 to break the seal between aperture 15 and seat 12 thereby allowing water to flow from the riser pipe through from passageway 8 into the chamber 14 and out through outlet 10.

The position of the valve seat 12 within chamber 14 can, as previously noted, be adjusted by screwing the valve 4 inwardly or outwardly of chamber 14 and therefore providing a fine adjustment in respect of the water pressure required to cause sealing contact to be made between diaphragm 3 and valve seat 12.

It is not essential that the drainage valve includes the spring member 5, but its presence is desirable since it assists diaphragm 3 in overcoming the pressure of water contained in the riser pipe with the supply valve turned off to ensure that the pipe will be drained of water.

In the embodiment of Fig. 2 the draining valve consists of an outlet connection 100 providing a passageway 108 that screwthreadedly engages a corresponding threaded portion at the bottom outlet of a hot and cold water mixing valve, washer 107 providing a watertight seal. Housing 102 screw-threadedly engages the open end 109 of outlet connec tion 100. Annular shoulder 120 projects inwardly of the walls of housing 102 and di vides the housing into two chambers 121 and 122 and provides a communicating aperture 124, drainage holes 110 formed in the lower face 111 of housing 102 communicate with chamber 121. A tubular support member 130 having an internal downwardly directed taper is secured in aperture 124 having a lower end 125 extending into chamber 121 and an up per end 126 extending into chamber 122.

A rolling diaphragm 112 has its outer edge 113 located between the interengaging shoulders of outlet connection 100 and housing 102 respectively to provide a watertight seal.

Diaphragm 112 includes a central substantially cylindrical portion 114 extending downwardly into support member 130, the lower end of said portion providing an aperture 115.

A cylindrical valve member 116 having a tapering valve seat 117 of maximum dimension greater than aperture 115, is scrawthreadedly engaged in an aperture 118 formed in face 111 of housing 102 and extends into chamber 121. Seat 117 projects through aperture 115 in diaphragm 112 into cylindrical portion 114 to provide a drainage passage between chambers 122 and 121 in the absence of supply water pressure acting on diaphragm 112. The amount by which taper 117 projects through aperture 115 can be varied by screwing valve 116 inwardly or outwardly of chamber 121. A lock nut 119, engaging the end portion 118 of valve 116 projecting outwardly of housing 102, can be tightened against the housing to secure valve 116 in the desired position.

In use the operation of this embodiment is the same as that of Fig. 1, supply water pressure causing the diaphragm to deform, causing aperture 115 to engage valve seat 117 and provide a watertight seal therebetween whereby water is prevented from flowing from chamber 122 into chamber 121. When the water supply pressure fails below a predetermined value the diaphragm reverts to its original shape and allows water to drain through passageway 8 into chamber 122, between aperture 115 and seat 117 into chamber 121 and out through drain holes 110.

If required a tension spring corresponding to spring 5 of Fig. 1 and acting in like manner can be included in chamber 121 to act between annular shoulder 120 and diaphragm 112.

The pressure of the support member 130 allows the drain valve to be used at pressure as high as 148.3 kp/cm2 (300 psi) by providing support for the diaphragm when it engages the seat 117. In the absence of such a support means the diaphragm tends to distort at high pressures to allow leakage passed seat 117.

Claims (7)

1. A drain outlet valve for use in water supply systems including riser pipes or the like and wherein the valve is connected to the lowermost point in the system, comprising a hollow housing having means for attachment to the said system to provide fluid flow communication therebetween, said housing including at least one chamber; a drainage hole formed in a lowermost portion of the housing to communicate with the chamber; a deformable closure member located in said housing to provide a watertight seal between the peri phery thereof and the inner walls of the housing to provide upper and lower compartments within said chamber and including an aperture to provide communication between said attachment means and the lowermost portion of said chamber; and adjustable valve means located in said housing and including a valve seat for co-operation with the aperture in the said closure member, whereby at a predetermined water supply pressure the said closure member is deformed to cause said aperture to engage said valve seat and provide a watertight seal therebetween, and at lower pressures a passageway is provided between said valve seat and said aperture to permit water from the system to flow through said attachment means into the housing and out through the drainage holes communuating with the said chamber.

2. A drain valve according to claim 1 wherein said deformable closure member is a rolling diaphragm including a substantially centrally located open-ended tubular portion extending towards said valve means to provide said aperture.

3. A drain valve according to claim 2 wherein said housing includes an inwardly directed annular shoulder to define upper and lower chambers with a communicating aperture, a substantially tubular support member being secured in said aperture and having a portion extending into each said chamber, said diaphragm being located in said upper chamber and the tubular portion thereof lying within said support member and directed towards said lower chamber.

4. A drain valve according to claim 1, 2 or 3 wherein there is included a tension spring acting between said closure member and the bottom of said housing or said annular shoulder, the tension in said spring being lower than the predetermined water pressure needed to provide a seal between the closure member and the valve seat.

5. A drain valve according to any one of claims 1 to 4 wherein the valve member is screw-threadedly secured in said housing for adjustment towards and away from said closure member whereby the water pressure in the system at which the closure member is caused to seal by engagement against the valve seat may be varied, the said valve seat being tapered.

6. A drain valve according to any one of the preceding claims wherein the housing is substantially cylindrical.

7. A drain outlet valve for use in water supply systems substantially as herein described with reference to Figs. 1 or 2 of the drawings.