1989 Ed.]
Waterworks Regulations
[CAP. 102
A 27
[Subsidiary]
5.
Ball valves or float-operated valves fitted to storage cisterns shall be securely and rigidly fixed thereto above the water-line, and shall be supported independently of the inlet pipe (unless such inlet pipe is itself rigid and rigidly fixed to the cistern), in such a position that no part of the body of the valve will be submerged when the cistern is charged to overflowing level.
6.
Where a ball valve or float-operated valve is provided with a pipe so arranged as to discharge water into a cistern below its overflowing level, an air hole shall be provided in the outlet chamber of the valve above such level of a size sufficient to prevent siphonage of water back through the valve.
7.
No ball valve shall be fitted to a storage cistern to contain heated water.
8.
9.
Gate valves shall comply with BS 5154 for copper alloy gate valves for general purposes.
Fitting with threaded outlets, or any device facilitating the connecting of rubber or other type flexible hose, shall not be permitted, except with the written permission of the Water Authority.
10. Draw-off taps, valves and valve floats for use with salt water shall, where applicable, comply with the British Standard and other requirements for such fittings for use with fresh water and shall, in addition, be manufactured from materials capable of withstanding the corrosive effect of salt water.
11. No draw-off tap or valve shall be installed or used unless it has been tested and stamped in accordance with regulation 21 or otherwise approved by the Water Authority.
(L.N. 252 of 1977)
1.
PART III
COLD WATER STORAGE CISTERNS
No cistern for the storage of cold water shall be installed or used except with the permission in writing of the Water Authority who shall specify the maximum permitted capacity.
2. Every cistern shall be watertight, of adequate strength, properly supported and shall be constructed of concrete, galvanized iron or steel or other approved material.
3. A cistern of mild steel not exceeding 5 000 litres capacity shall comply with BS 417, Part 2 for galvanized mild steel cisterns.
4.
(a) Every cistern shall be located so as to minimize the risk of contamination of the stored water and shall be fitted with suitable close fitting lockable covers which shall not be air-tight. Covers shall be positioned so as to facilitate inspection and cleaning.
(b) Where a storage cistern for non-potable water is placed adjoining to a storage cistern for potable water there shall be an air space between such storage cisterns.
5. Cisterns shall be fitted with a ball valve controlled inlet in the case of a gravity supply or with an automatic control switch in the case of a pumped supply. The ball valve or control switch shall shut off the supply when the water level is 25 mm below the invert of the overflow pipe. The invert of the inlet pipe or the face of the outlet nose of the ball valve shall be not less than 25 mm above the top of the overflow pipe.
6. An overflow pipe of one commercial size larger than the inlet pipe, and in no case less than 25 mm diameter, shall be fitted to each cistern and shall be extended to terminate in a conspicuous position. No overflow pipe shall be connected to a drain, sewer or to the overflow pipe from any other cistern.
7. A stop valve shall be provided on the outlet of every cistern and provision shall be made for a drain-off pipe to enable the cistern to be emptied.
8.
No cistern for the storage of fresh water supplied from the waterworks shall, without the written permission of the Water Authority, be so connected that it can be used for the storage of any water other than that supplied from the waterworks.