BS EN 161:2002 pdf download
BS EN 161:2002 pdf download.Automatic shut-off valves for gas burners and gas appliances.
6.1.8 Soldering or other processes where the jointing material has a melting point below 450 C after application shall not be used for joining gas-carrying parts except for additional sealing.
6.1.9 Closed position indicator switches, where fitted, shall not impair the correct operation of valves Adjusters shall be sealed to indicate interference. Any drift of the switch and actuating mechanism from its setting shall not impair correct valve operation.
6.1.10 Flow rates of valves with modulating control shall be adjustable over the full range declared by the manufaclurei-, If the adjustment of one flow rate affects the setting of any other flow rate, this shall be clearly indicated In the manufacturer’s instructions for setting up. The setting of any flow rate shall require the use of tools and shall be sealed to discourage unauthorized adjustment.
6.2 Materials
6.2.1 General material requIrements
The quality of materials, the dimensions used and the method of assembling the various parts of the valve shall be such that construction and performance characteristics are safe Performance characteristics of the valve shall not alter significantly during a reasonable life when installed and used according to the manufacturer’s instructions. Under these orcunistanoes, al components shall withstand any mechanical, chemical, and thermal conditions to which they may be subjected during service.
62.2 Zinc alloys
Zinc alloys shall only be used for gas-carrying parts of valves up to ON 50 with maximum worlung pressures up to 200 mbar if of quality ZnAI4 to ISO 301:1961 and if the parts do not exceed a temperature of 80C. Where the main inlet or outlet threaded connections are made of zinc alloys, threads shall be external and conform to ISO 226-1:2000.
6.2.3 Housing
Parts of the housing which directly or indiectly separate a gas-carrying corn partrnent from atmosphere shall either be made from metallic materials, or shall be such that, on removal or fracture of non-metallic parts other than 0-rings. gaskets. seals and diaplwagms. no more than 30 dm3Th of air escapes at the maximum working pressure, when tested to 8.7.2.2.
6.2.4 Closure members
Closure members of valves above ON 25 shall either have a mechanical support (e.g. metallic) to withstand the sealing force or shall be made of metal.
This requirement also applies to:
— all valves with a maximum working pressure above 150 mbar:
— parts transmitting the closing force.
6.2.5 SprIngs providing closing force and sealing force
Closing force and sealing force shall be provided by spring action. Springs providing the closing and sealing forces shall be designed for oscillating loads and for fatigue resistance. Springs with wire diameter up to and including 2.5 mm shall be made from corrosion.resistant materials.
Springs with wire diameter above 2,5 mm shall either be made from corrosion-resistant materials or shall be protected against corrosion.
63.4 Compression fittings
Compression fittings shall be si.iitable for use with tubes of outside diameter to ISO 274:1975, Table 2. It shall not be necessary to form the tubes before making connections. Olives shall be appropriate to the tubes for which they are intended Non-symmetrical olives may be used provided they cannot be fitted inoorrecy
6.4 Seals for glands for moving parts
Seals for moving parts mat pass through the body to atmosphere and seals for the closure member shall be made only of soed, mechanically stable material of a type which does not deform permanently. Sealing paste shall not be used.
Manually adustab4e packing glands shall not be used for sealing movrig parts.
NOTE An adustabIe gland Sal by the manufacturer and protected against further adjustment is considered to be non-acustle.
Bellows shall not be used as the sole sealing element against atmosphere.
6.5 Pressure test points
Pressure test points shall have an external diameter of mm and a useful length of at least 10 mm for connection to tubing. The equivalent diameter of the bore shall not exceed 1 mm.
6.6 Strainers.
