GB2233680A - Silencing system for a ball cock valve - Google Patents

Abstract

A mains fed water storage tank incorporating a ball cock valve is provided with a silencing system. The system includes a hollow dip tube 22 extending from the discharge spout 14 of the valve 2 to below the water level in the tank. The dip tube 22 has at its upper end a series of openings 26 to prevent back syphoning of water up the tube 22. A chamber member 20 surrounds the section of the tube 22 with the openings, to contain any water emerging from the openings. The chamber member 20 directs such water as is collected down along the outside of the tube 22 for silent entry into the water. The upper end of the chamber is provided with air vents 24. <IMAGE>

Description

LIQUID SILENCING SYSTEM The present invention relates to liquid silencing systems.

Low pressure tanks such as toilet systems employ a water inlet valve controlled by a lever to which a floatation ball is attached. As water is admitted by the valve into the tank, the level of the water rises and causes the floatation ball in turn to rise. The rise of the floatation ball causes the lever to pivot in a sense to close the valve.

Normally, the valve is located well above the level of the liquid and so as water is dispensed by the valve it falls freely onto the surface of the water below making a noise and therefore a nuisance. To eliminate such noise a hollow dip tube is provided to extend downwardly from the valve to a sufficient extent such that it always lies below the level of the liquid.

This provides a significant silencing effect on the water being dispensed from the valve.

The problem with this system is that there is a danger that if the valve is subject to a negative pressure, the water in the tank will be subject to a syphonic effect and so be pulled back into the low pressure supply system. If the water in the system happens to be contaminated then this will contaminate the whole of the low pressure supply system. Because such low pressure systems are isolated from the incoming water mains system any contamination is purely localised.

If such a hollow dip tube were coupled to a valve supplied directly from the water mains and feeding a storage tank, any contamination, for example, as a result of a dead bird falling into the tank, would be likely to be widespread throughout the water mains system. It is for this reason that most water boards prohibit the use of a dip tube silencer in a tank supplied directly by the mains.

It is an object to provide an improved liquid silencing system.

According to the present invention there is provided a liquid silencing system comprising a hollow conduit arranged to extend downwardly from a discharge spout of a valve to below a first predetermined lower level, the conduit being provided with openings in the wall thereof above a second predetermined upper level, a chamber enclosing the conduit in the region of the openings and having air vents in a region thereof above said second predetermined upper level and a discharge outlet in a region thereof below said second predetermined upper level, the chamber being so profiled as to direct liquid from the discharge outlet towards the outer surface of the conduit for flow along the outer surface of the conduit down to the first predetermined lower level.

Liquid silencing systems embodying the present invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings in which: Figure 1 is a section through of a first ball cock valve and associated silencing system; Figure 2 is a fragmentary exploded view of the system of Figure 1; and Figure 3 is a side elevation of a second ball cock valve and associated silencing system.

Figure 1 shows a ball cock valve 2 mounted on the wall 4 of a tank for storing water. The valve 2 is clamped to the wall 4 at a level above the overflow outlet (not shown) of the tank. The valve 2 has a cylindrical body housing a tapered orifice 6 and an elongate cylindrical sliding member 8. The member 8 has a recess at one axial end accomodating a rubber washer 10 which when the valve is closed is urged against the orifice 6. Directly below the orifice 6 is a cylindrical outlet spout 14 extending radially outwardly and downwardly from the cylindrical body. A lever 16 is pivotally secured to a pair of ears 18 (only one shown) rigid with, and extending radially from, the cylindrical body. One end 16A of the lever (which is dog leg shaped) extends through a slot in the underside of the cylindrical body and engages a channel in the sliding member 8.An elongate arm 18 extends from the other end 163 of the lever and terminates in a floatation ball 19.

In operation when the water level in the tank rises the ball 19 is lifted up and thus causes the lever 16 to pivot in an anticlockwise sense (as viewed in Figure 1). The end 16A of the lever engages the axial end of the slot and displaces the member 8 towards the orifice 6 until the supply of water from the orifice is cut off. When the water level in the tank falls, the ball 19 drops and this pivots the lever 16 in a clockwise sense pulling the end 16A of the lever away from the axial end of the slot. The water pressure in the orifice 6 urges the cylindrical member 8 away from the orifice and water is now discharged from the orifice to pass through the outlet spout 14.

A dip tube 22 extends from the spout 14 downwardly to below the level of the water in the tank. At its upper end, the dip tube 22 has a series of openings 26 at least some of which are arranged always to lie above the level of the water and in this way ensures that no syphonic effect can take place. Thus if the outlet spout 14 is subject to negative pressure through the valve 2, air will be drawn into the openings 26 and the air, rather than the water in the tube, will be drawn back into the water main system. Any water in the tube will then fall under gravity to the level of the water in the tank.

Because of the pressure of the water discharged from the spout, water will inevitably be discharged from the holes 26 and cause a certain amount of noise in falling to the water level below.

Accordingly, the upper section of the tube 22 is enclosed in a chamber member 20 defining a chamber.

The member 20 is of circular cross-section and has an enlarged central region and two tubular ends 20A and 20B. A tapered section joins each tubular end with the englarged central region. The upper tubular end 20A is arranged to be a push fit into the spout 14. The upper end of the tube 22 is arranged to be a push fit into the upper tubular end of the member 20. The free end of the upper tubular end 20A is split longitudinally (see Figure 2) and slightly tapered inwardly towards the extremity. Thus during assembly, the end 20A can be easily inserted into the spout 14. If then the upper end of the dip tube 22 is forced into the tubular end 20a, the split portions of the end 20A will be forced apart into tight engagement with the inner wall of the spout.

Thus both the chamber member 20 and the dip tube 22 will be rigidly supported from the spout.

The lower tubular end 20B of the chamber member has an internal diameter somewhat larger than the external diameter of the dip tube and as a result the tubular end 203 and the dip tube 22 define an annular gap through which any water collected in the chamber of the chamber member 20 can escape. The upper tapered section of the chamber member is provided with a series of equilangularly spaced air vents 24 for admitting air to the chamber 20 both to allow water to escape from the annular gap and to admit air to the openings 26 in the event of the valve being subject to negative pressure.

In operation the majority of water discharged from the outlet spout 14 will pass along the dip tube 22 and enter the reservoir below the level of the water therein. Any water escaping from the openings 26 will be contained in the chamber member 20 and funnelled by the lower tapering section of the member 20 to the annular orifice where the water will tend to run down the outside of the dip tube to enter the water in the reservoir relatively silently.

In the event of a negative pressure in the valve 2, air will be drawn in through the vents 24 and the openings 26 to allow any remaining water in the dip tube 22 to fall into the reservoir to assume the water level in the tank and to admit air into the water mains systems through the valve 2.

In one modification the outer surface of the dip tube may be profiled to increase its surface area and to provide a more constraining path for water from the annular gap to the water level below.

For example a helical fin may extend around the outer surface of the dip tube. Other suitable profiles will be apparent to persons of ordinary skill.

In another modification, the portion of the dip tube 22 below the openings 26 may be closed off or solid. In this event the annular gap will need to be sufficiently large to allow all the water entering the chamber to be discharged at the same rate as it enters the chamber.

The closed off or solid portion of the dip tube can be shaped other than tubular and can be seperately coupled to the upper portion of the dip tube.

Instead of both the chamber member 20 and dip tube 22 being a push fit in the spout 14, the chamber member 20 can be secured to the dip tube (by adhesive or welding) at a location just below the spout 14. In this case only the dip tube is directly push fitted into the spout 14.

Advantageously the chamber member 20 is of transparent plastics material. The dip tube may also be of plastics material.

It will thus be appreciated that as water discharges from the spout 14, the majority will pass down the inside of the dip tube 22 to enter the water below the surface. That water which escapes through the openings 26 will be captured by the chamber member 20 and funnelled along the outside of the dip tube 22 to enter the water in the tank relatively silently.

In more currently available ball cock valves, the flow of water is controlled by a diaphragm mechanism in response to action of the lever 16 attached to the floatation ball. In such valves the discharge spout extends upwardly instead of downwardly and a 'U'-shaped tube or guide is provided to direct the emerging water downwardly to the bottom of the tank. The U-shaped tube has an outlet orifice which is higher than the centre line of the valve, and this ensures that even if the water level in the tank rises to the centre line, there will still be no possibility of back syphoning in the event of negative pressure.

Figure 3 shows such a valve 48 provided with a silencing system.

The U-shaped tube of the conventional valve 48 is replaced by a modified generally U-shaped adaptor providing a downwardly directed outlet spout 52. The spout 52 is located well above the centre line of the valve so that when a chamber member 20 and dip tube 22 (similar to those used in the embodiment of Figure 1) are push fitted into the spout, all the openings 24 and 26 and preferably the annular outlet all lie above the centre line of the valve 48.

In this way the criteria preventing back syphoning is maintained.

It will be appreciated that the dip tube and chamber member described are adapted to be fitted to existing valves. It will, however, be apparent that the principles employed can be used in making them an integral part of a new valve.

Claims (10)

1. A liquid silencing system comprising a hollow conduit arranged to extend downwardly from a discharge spout of a valve to below a first predetermined lower level, the conduit being provided with openings in the wall thereof above a second predetermined upper level, a chamber enclosing the conduit in the region of the openings and having air vents in a region thereof above said second predetermined upper level and a discharge outlet in a region thereof below said second predetermined upper level, the chamber being so profiled as to direct liquid from the discharge outlet towards the outer surface of the conduit for flow along the outer surface of the conduit down to the first predetermined lower level.

2. A system according to Claim 1 wherein said conduit is solid or closed below said second predetermined upper level.

3. A system according to Claim 1 or Claim 2 wherein said chamber is defined by a cylindrical member having a central portion of enlarged diameter, two tubular end portions and a tapering portion linking each tubular end portion with the enlarged central portion.

4. A system according to Claim 3 wherein the lower of the two end portions defines with the conduit an annular gap.

5. A system according to Claim 3 or to Claim 4 wherein the upper of the two tubular end portions comprises a push fit into the said discharge spout and wherein the upper end of the conduit is a push fit into the said upper tubular portion.

6. A system according to Claim 5 wherein the upper of said two tubular end portions has at least one longitudinal split in a wall thereof.

7. A system according to Claim 3 or to Claim 4 wherein the upper one of said two tubular end portions is secured to said conduit by adhesive or welding and wherein said conduit is a push fit in said discharge spout.

8. A system according to any preceding claim wherein the member defining the chamber is transparent.

9. A liquid silencing system substantially as hereinbefore described with reference to the accompanying drawings.

10. A ball cock valve incorporating a liquid silencing system according to any preceding claim.