BS 5990:2006 pdf download – Specification for direct gas-fired forced convection air heaters with rated heat inputs greater than 330 kW but not exceeding 2 MW for industrial and commercial space heating – Safety and performance requirements (excluding electrical requirements) (2nd family gases)
Materials shall be of a type, quality and thickness appropriate to the application. In particular, all parts of the equipment shall be resistant to mechanical stresses, including shock, vibrationally or chemically or thermallyinduced, to which theymay be exposed during any conditions ofoperation. Under normal conditions of use, maintenance and adjustment, they shall show no changes that might adversely affect their function. Such materials, fittings and finishes shall conform to the requirements of the relevant British Standards and shall all be appropriate to the conditions arising in the part of the appliance in which they are used. The appliance and its components shall be free from swarf, grit or other foreign matter.
7.1.2 Component location Parts that are intended to be removable for maintenance or cleaning shall be readily accessible, shall be easy to assembly correctly and impossible to assemble incorrectly where incorrect assembly would create a hazardous condition or result in damage to the appliance and its controls. The burner(s) shall be positively located and so arranged that misalignment cannot occur. It shall not be possible to loosen complete burner assemblies, jet or injectors without the use of tools.
7.1.3 Materials in contact with gas Copper tubing shall not be used where it is likely to be exposed to temperatures above 100 °C. Solder that has a melting point below 450 °C after application shall not be used for gas-carrying parts.
7.1.4 Insulation Thermal or acoustic insulation shall be non-combustible in accordance with the requirements of BS 476-4, shall be securely located and shall be protected against mechanical damage, condensate and vermin. Gas-carrying in contact with, or passing through, insulating material shall be adequately protected against possible corrosive effects of the insulant.
7.1.5 Fire behaviour properties The appliance shall, wherever possible, be constructed of materials that are non-combustible in accordance with the requirements of BS 476-4. Any coating that may be applied to the outside surface of the appliance shall have class 1 surface spread of flame characteristics when tested on the substrate according to the requirements of BS 476-7. Air filter material shall possess ignitability characteristics designated ‘P’ when tested in accordance with BS 476-12.
7.1.6 Fan compartment Access to the air fan compartment for maintenance shall not be possible without the use oftools.
7.1.7 Gas connections Gas inlet connections shall be suitable for connection to one of the following. a) Tapered thread installation pipes in accordance with BS EN 10226-1 and BS EN 10226-2; b) Flanged pipes and fittings in accordance with BS EN 1092-1, BS EN 1092-3 and BS EN 1515-1, or BS 10.
7.1.8 Bolts and screws Drillings for bolts and screws shall not connect with fuel gasways. The minimum wall thickness shall be at least 1 mm. Self-tapping screws are not recommended but, where they are used to secure components that are removed during servicing, they shall be fitted with spire-type clips. Where hexagon headed screws are used to secure components that are removed during servicing, they shall be provided with screwdriver slots, where possible, if this facilitates servicing.
7.1.9 Viewing port Means shall be provided to allow the installer, commissioningengineer or servicing engineer to observe the pilot and main burner flames. If the means of observation is a viewing port, it shall, when locatedin an area of positive pressure and high temperature, be covered with heat resistant, toughened glass and sealed with a suitable heat resistant sealant.
There shall be easy access to components and controls that may require servicing or adjustment.
The appliance shall be fitted with access doors or removable panels to facilitate servicing.BS 5990 pdf download.