BS EN 525:2009 pdf free download – Non-domestic direct gas-fired forced convection air heaters for space heating not exceeding a net heat input of 300 kW.
c) a change, if necessary, of the automatic shut-off valve(s);
d) putting the regulator out of service in accordance with the requirements of 5.2.6;
e) putting the gas rate adjuster(s) out of service under the conditions given in 5.2.2.
These adjustments or component changes are only acceptable when:
f) converting from a gas of the 2nd family to a gas of the 3rd family or vice versa;
g) converting from one butane/propane pressure couple to another (e.g. 28-30 mbar/37 mbar to 50 mbar/67 mbar and vice versa).
5.1.1.4 Category Ill
Category Ill appliances that are permitted in certain countries are given in A.3.3 and A.3.4.
5.1.2 Materials and method of construction
The quality and thickness of materials used in the construction of the appliance and the method of assembling the various parts shall be such that the constructional and performance characteristics do not alter significantly during a reasonable life and under normal conditions of installation and use.
In particular, when the appliance is installed according to accepted practice, all components shall withstand the mechanical, chemical and thermal conditions to which they may be subjected in the course of normal operation.
Copper shall not be used for gas-carrying parts where its temperature is likely to exceed 100 °C.
Asbestos or materials containing asbestos shall not be used.
Solder that has a melting point below 450 °C after application shall not be used for gas-carrying parts.
5.1.3 Accessibility for maintenance and use
Parts that are intended to be removable for maintenance or cleaning shall be readily accessible, shall be easy to assemble correctly and difficult to assemble incorrectly. Such parts shall be impossible to assemble incorrectly where incorrect assembly would create a hazardous condition or result in damage to the appliance and its controls.
It shall be possible to clean the parts in contact with combustion products without using special tools unless these are supplied as necessary accessories with the appliance.
All parts required to be operated during normal use of the appliance (e.g. handles and buttons), shall be accessible without it being necessary to remove any part of the case. For this purpose, the opening of a door or access panel is permitted.
Constructional parts accessible during use and maintenance shall be free from sharp edges and corners that might cause damage or personal injury during use or maintenance.
Panels that are normally removed for servicing shall be fitted with a means of retention where the appliance is intended to be installed more than 1,8 m above floor level, measured from the underside of the appliance. This requirement shall be deemed to be satisfied if suitable hinges are fitted.
5.1.4 Thermal insulation
Any thermal insulation shall retain its insulating properties under the influences of heat and ageing. The insulation shall withstand the thermal and mechanical stresses expected during normal operation. The insulation shall be non-combustible and securely located. It shall be protected against mechanical damage, the effects of condensate and attacks from vermin.