BS EN 521-2019 Specifications for dedicated liquefied petroleum gas appliances – Portable vapour pressure liquefied petroleum gas appliances.
5 Safety requirements
The test methods and the means of verification are indicated in Clause 6.
The design shall make it impossible to incorrectly fit or refit any user-removable or replaceable part(s) or component(s) that can have an adverse effect on combustion or cause CO emissions to exceed limits in Clause 5.26.
5.2 Adjustment of the burner
For appliances of types a). b) and c) of the scope of this European Standard, not any adjustment of the burner shall be possible.
Non-metallic materials used as radiant elements in appliances (for example volcanic rocks, refractory blocks) shall be of a quality suitable to their use.
The quality and thickness of materials used in the construction of appliances shall be such that the constructional and performance characteristics are not altered in use. In particular all the parts of the appliance shall withstand mechanical, chemical and thermal actions to which they may be submitted during use. In normal conditions of operation, of cleaning or of adjustment, they shall not be liable to any alterations which might impair their safety.
Sheet-metal parts, not made of corrosion-resistant material, shall be effectively protected against corrosion. This requirement does not apply to grilles supporting lava rocks nor to cooking devices.
Seals and joining compounds shall have characteristics suited to their use.
Rubber based materials shall comply with EN 549:1994 class A2 minimum, and LPG resistant.
Hoses being part of the appliance shall be LPG resistant.
Copper tubing shall be used upstream of the injector only if its temperature does not exceed 100 °C
when the test described in 6.21 is carried out.
Asbestos or asbestos based materials shall not be used.
5.4 Assembly, cleaning and maintenance
The entire appliance gas circuit, including the injector and flexible hoses if any, shall be factory assembled. If clamps are used, they shall be of the machine formed type. Removable clamps are not permitted.
Parts, whose assembly is carried out by the user, shall be able to be assembled correctly by following the instructions given in the instructions.BS EN 521 pdf download.