GB2242474A - Installation for protecting water piping against freeze damage - Google Patents

Abstract

A water storage tank (10) is supplied with mains water through a rising main (11) and the usual ballcock valve mounted in the tank. The rising main (11) has a normally closed water inlet valve (12) which has electrically energisable means connected to be energised to hold the valve open. The valve (12) reverts to its closed condition under the control of a thermostat (13) when the temperature of the water in the tank falls to near freezing. A normally closed electrically operable-to-open dump valve (14) is provided and is controlled by the thermostat to open when the inlet valve (12) closes. <IMAGE>

Description

IMPROVEMENTS IN INSTALLATIONS FOR THE SHUT-OFF OF THE MAINS WATER FEED TO A WATER STORAGE TANK IN THE EVENT OF THE DANGER OF FREEZING The present invention relates to an installation for the automatic shut-off of the mains water feed to a water storage tank, e.g. in domestic or other premises, in the event of the danger of freezing.

Current practice in house construction is to provide a free air flow through the roof space by creating air gaps in the loft space. To minimize heat losses in the house, a greater degree of loft insulation is used, directly between the ceiling and the loft area.

The objective of this practice is to prevent timber rotting of the roof rafters and joists. The result reduces the temperature in the loft space, putting water pipes and the header tank at risk by freeze-up.

In addition, when the house is unoccupied the risk is further increased due to the static condition of water in the pipes and storage tank.

It is well known that extensive water damage can be caused to property due to burst pipes, particularly if the property is unattended.

Various systems have hitherto been proposed not only to shut off the mains water feed to a water storage tank automatically in response to the fall of the temperature to freezing, but also to drain the the pipework and the storage tank automatically of water.

The object of the present invention is to provide an improved system which is relatively simple and cheap to install and which is economical in regard to its wastage of water.

According to the present invention there is provided an installation for the automatic shut-off of a mains water feed in a mains water feed pipe to a water storage tank in domestic or other premises in the event of a danger of the water freezing, said installation including an electrical power supply, a temperature sensing means, a normally closed inlet valve in the mains water feed pipe having electrically energizable means which holds the inlet valve open when energized, manually operable means associated with the inlet valve and operable to adjust the valve into an open position, and a normally closed, electrically operable-to-open water dump valve in a drain pipe connected with the tank and leading outside the building, said temperature sensing means being connected in an electrical circuit with said electrically energizable means and said electrical power supply and being operable to maintain said electrically energizable means energized so long as the temperature is above a preselected temperature at which water is in danger of freezing and said dump valve being electrically connected with said electrical power supply to be operable under the control of said temperature sensing means when said electrically energizable means is deenergized.

A specific embodiment of the present invention will now be described in detail by way of example with reference to the accompanying drawings in which: FIG. 1 is a diagram; FIG. 2 is an elevation, partially in cross section of a normally closed water shut-off valve employed in an installation of the present invention; and FIGS. 3A and 3B are parts of Fig. 2 to a larger size and showing the alternative positions of a reset means.

With reference now to the accompanying drawings and first to Fig. 1, a water storage tank 10 is supplied with mains water through a rising main 11 and the usual ballcock valve (not shown) mounted in the tank. The rising main 11 has a normally closed, water inlet valve 12. The valve 12 has electrically energizable means connected to be energized to hold the valve open.

The valve 12 is permitted to revert to its closed condition under the control of a thermostat 13 when the temperature of the water in the tank falls to a tempera ture in the vicinity of freezing. The valve 12 has a manually operable means for adjusting the valve into its open position and for selectively maintaining the valve in its open position as will be fully described below.

The installation further comprises a normally closed, electrically-operable-to-open, dump valve 14 connected to be operated under the control of the thermostat 13 to open when the electrically energizable means of the valve 12 is de-energized, thus permitting the inlet valve to close. The dump valve 14 is positioned in an outlet pipe 19 having an internal diameter of not less than 22 mm for draining the water from the tank 10. The dump valve 14 is conveniently a solenoid operated valve, the valve closing automatically, e.g.

under the action of a spring when its solenoid is deenergized and opening against the action of its spring when its solenoid is energized. Any suitable known valve of this kind may be utilized in the present installation.

The thermostat 13 is positioned in a region immediately adjacent the tank 10 and is of the kind having a capillary tube 13a with a bulb 13b normally immersed in the water in the tank. The valve 14 is positioned in a region close to the ceiling joists so that the valve 14 can be thermally insulated against the effects of freezing, and the pipe 19 leads directly across ' the roof space to the outside of the building through a hole in the usual eaves board, the pipe 15 being connected and provided with a suitable fall to drain the whole contents of the tank 10. The valve 12 is positioned at a remote and suitably accessable position in the building and preferably close to the ground level.

The valve 12 is shown in detail in Figs. 2 and 3 and has a low power, 240V. D.C. solenoid 15 associated with an iron core 16. The solenoid 15 is energizable to hold the core 16 in its position shown in Fig. 3A, against the action of a spring 17 which normally returns the core 16 to a position as shown in Fig. 3B. The core 16 carries a seal '8 which then closes a water bleed passage 19 to allow the bFild-up of mains water pressure in a valve cavity 20 on the upper side of a diaphragm carrying a valve member 22. The valve member 22 is forced by the build-up of mains water pressure in the cavity 20 on to a seating 24 communicating the mains water inlet passage 25 of the valve 12 with the mains water outlet passage 26 of the valve 12, thus closing and holding the valve 12 closed.

The valve housing journals a rotatable shaft 30 suitably sealed in the housing, the shaft carrying an eccentric pin 32 at its inner end.

The shaft 30 is manually rotatable by means of a finger grip 34. carried at its outer end, outside the valve housing. The eccentric pin 32 is positioned to engage and lift the core 16 from its Fig. 3B to its Fig. 3A position when the shaft 30 is turned 1800 from its Fig.

3B position, the pin 32, in its Fig. 3B position, lying out of contact with the core 16 and in a position in which it is unable to interfere with movement of the core 16 in any way.

To arm the installation, an electrical mains switch 40 is turned on thereby to energize a D.C. bridge 41. The bridge supplies a D.C. voltage to the solenoid 15. In the meantime, the core 16 is held out of magnetic position by its spring and the solenoid 15 is unable to attract the core 16 into the solenoid against the action of the spring. The shaft 30 is turned 1800 from its Fig. 3B to its Fig. 3A position to adjust the core 16 into its Fig. 3A position and open the valve 12.

The core 16 is then in magnetic position and is retained in its Fig. 3A position by the solenoid 15. The shaft 30 is turned 1800 to return the eccentric pin 32 to its Fig. 3B position. The tank 10 fills with water and is maintained full of water in the usual way.

The thermostat 13 is set to operate when the temperature of the water in the tank 10 drops to 20C.

Preferably, the thermostat is preset and sealed so as to be non-adjustable by the householder.

Upon operation of the thermostat 13, the D.C.

current supply to the solenoid 15 is interrupted by opening of the thermostat contacts 1 and 4 and the core 16 reverts to its Fig. 3B position causing the valve 12 to close. At the same time, the operation of the thermostat 13 closes the contacts 1 and 2 to connect the normally closed dump valve 14 to the electrical power source at switch 40 and the dump valve is opened to drain the tank 10.

If the temperature rises above 20C, whilst the installation is still unattended, the thermostat t3 restores power to the solenoid 15 but the valve 12 is prevented from re-opening until the core 16 is reset, by turning the shaft 30. This enables the pipework to be checked for leaks by the householder which may otherwise cause damage to the premises and its contents.

In the event of a power failure, the valve 12 is closed but the tank 10 is not drained of water When power is restored the installation must be re-armed by turning the shaft 30 through 3600. Therefore, the building is still protected against the effects of continuously running water escaping from the inlet mains supply. Also, if desire, the water supply may be restored by turning the shaft 30 1800 to its Fig. 3A position.

Since the contents of the tank 10 is drained only when the inlet valve 12 is closed, no more than one tank full of water can be wasted. Furthermore, since the inlet valve, once closed, must be reset to open, failure of the dump valve to reclose can always be checked to prevent further wastage.

Because of the low power requirement, e.g. 3 to 5 watts of the solenoid 15, the system is cheap to operate.

The shaft 30 is conveniently provided with positioning stops (not shown) associated with the finger grip 34, one stop positioning the shaft in its Fig.

3A position and another in its Fig. 3B position. In this case the shaft is turned 1800 in one direction and then 1800 in the opposite direction when arming or re-arming the installation.

Claims (4)

CLAIMS:

1. An installation for the automatic shut-off of a mains water feed in a mains water feed pipe to a water storage tank in domestic or other premises in the event of a danger of the water freezing, said installation including an electrical power supply, a temperature sensing means, a normally closed inlet valve in the mains water feed pipe having electrically energizable means which holds the inlet valve open when energized, manually operable means associated with the inlet valve and operable to adjust the valve into an open position, and a normally closed, electrically operable-to-open water dump valve in a drain pipe connected with the tank and leading outside the building, said temperature sensing means being connected in an electrical circuit with said electrically energizable means and said electrical power supply and being operable to maintain said electrically energizable means energized so long as the temperature is above a preselected temperature at which water is in danger of freezing and said dump valve being electrically connected with said electrical power supply to be operable under the control of said temperature sensing means when said electrically energizable means is deenergized.

2. An installation as claimed in claim 1 wherein the electrically energizable means is a solenoid and the manually operable means is operable to displace a solenoid core of the solenoid from a normal position into magnetic position in the solenoid, the core normally -being held out of magnetic position in the solenoid, e.g. by a spring.

3. An installation as claimed in claim 2 wherein the manually operable means comprises a rotatable shaft having an eccentric pin to engage and shift the solenoid core from its normal position into its magnetic position when the shaft is rotated.

4. An installation for the automatic shut-off of a mains water feed into a mains water feed pipe to a water storage tank in domestic or other premises in the event of a danger of the water freezing substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.