BS EN 777-2-2009 pdf download.Multi-burner gas-fired overhead radiant tube heater systems for nondomestic use Part 2: System E — Safety.
5.1.1.2.1 Categories of systems designed for use with gases of the first and second families Adjustment of the gas rate with, if necessary, a change of injector, restrictor or regulator.
Adjustment of the gas rate of the ignition burner, either by using an adjuster or by a change of injector or restnctor and, if necessary, a change of the complete ignition burner or of some of its parts.
Putting the regulator out of service under the conditions of 5.2.6.
Putting the gas rate adjuster(s) out of service under the conditions of 5.2.1 and 5.2.2 if applicable.
The adjustments or component changes are only acceptable when converting from a gas of the first
family to a gas of the second family or vice versa.
5.1.1.2.2 Categories of systems designed for use with gases of the second and third families
Adjustment of the gas rate with, if necessary, a change of injector, restrictor or regulator.
Adjustment of the gas rate of the ignition burner, either by using an adjuster or by a change of injector or restrictor and if necessary, a change of the complete ignition burner or of some of its parts.
Putting the regulator out of service under the conditions of 5.2.6.
Putting the gas rate adjuster(s) out of service under the conditions given in 5.2.1 and 5.2.2 if applicable. The adjustments or component changes are only acceptable when:
a) converting from a gas of the second family to a gas of the third family or vice versa;
b) converting from one butane/propane pressure couple to another (e.g. 28-30/37 mbar to
50167 mbar).
5.1.1.3 Category UI
Category Ill systems admitted in certain countries are given in Annex A (see A.3.2.3).
5.1.2 Materials and method of construction
The quality arid thickness of materials used in the construction of a system including its POCED shall be:
a) such that the construction and performance characteristics are not altered so as to affect the safe operation of the system in normal conditions of use and of maintenance by the user:
5.1.3 Accessibility for maintenance and use
Components and controls shall be arranged such that any adjustment, maintenance or exchange is easy without removing the radiant tube from the installed position. Where necessary, access doors or removable panels shall be provided.
Parts that are intended to be removable for maintenance or cleaning shall be readily accessible, shall be simple to assemble correctly and difficult to assemble incorrectly. Such parts shall be difficuft to assemble incorrectly where incorrect assembly would create a hazardous condition or result in damage to the system and its controls.
Parts of the system which are not intended to be removed by the user and for which removal would affect safety shall be capable of removal only with the aid of tools.
5.1.4 Means of sealing
5.1.4.1 Soundness of the gas circuit
Holes for screws, studs, etc., intended for the assembly of components shall not open into the gasways. The wall thickness between holes (including threads) and gasways shall be not less than 1 mm.
The soundness of components and assemblies connected to the gas circuit and likely to be dismantled for routine maintenance at the customer’s premises shall be assured by means of mechanical jornts, (e.g. metal to metal joints, 0-ring joints or packing), but excluding the use of any sealing compound (e.g. tape, mastic or paste). The soundness shall be maintained after dismantling and reassembly.
Sealing compounds shall be used for permanent threaded assemblies. The sealing material shall remain effective under normal conditions of system use.
5.1.4.2 Soundness of the combustion circuit
The soundness of the combustion circuit of the system shall be effected by mechanical means only, with the exception of those parts which do not require to be disconnected for routine maintenance, and which may be joined with mastic or paste in such a way that permanent soundness is assured under normal conditions of use (see 8.2.2.1 c). The means of sealing the connection shall be the same for both the common duct and the branch duct.
5.1.5 Supply of combustion air and evacuation of combustion products
5.1.5.1 AIr inlets
All openings for the supply of air into the system shall be adequately protected against inadvertent blockage. In addition, such openings shall not permit the entry of a ball of 16 mm diameter applied with a force of 5 N. The cross section of the air passaqeway(s) shall not be adiustable.BS EN 777-2-2009 pdf download.