UL 307B-2009 pdf download

UL 307B-2009 pdf download.Gas-Burning Heating Appliances for Manufactured Homes and Recreational Vehicles.
3.9 BURNER HEAD – That portion of a burner beyond the outlet end of the mixer tube which contains the ports. 3.1 0 CENTRAL FURNACE – A self-contained appliance for heating air by transfer of heat of combustion through metal to the air, and designed to supply heated air through ducts to spaces remote from or adjacent to the appliance location. 3.1 1 COMBUSTIBLE MATERIAL – As pertaining to materials adjacent to or in contact with heat- producing appliances, chimney and vent connectors, steam pipes, and warm-air ducts, combustible material is that material made of or surfaced with wood, compressed paper, plant fibers, or other material that will ignite and burn. Such material is considered to be combustible even though flame- proofed, fire-retardant treated, or plastered. 3.1 2 CONDENSATE – The liquid which separates from the combustion by-products of a fuel (flue gases) due to a reduction in temperature below dew point. 3.1 3 CONTROL – a) Fan – An automatic control intended to control the operation of the fan on forced air appliances. b) Limit – An automatic safety control responsive to changes in liquid level, pressure, or temperature and intended to be set beyond the operating range for limiting the operation of the controlled equipment. c) Low Water – A control that automatically cuts off the fuel supply when the surface of the water falls to the lowest safe water level. This point should not be lower than the bottom of the water glass. d) Operating – A control, other than a safety control or interlock, to start or regulate burner firing according to demand and to stop or regulate firing on satisfaction of demand or upon reaching intended temperature or pressure in the appliance being fired.
3.1 9 HEATING SURFACES – All surfaces that transmit heat directly from flame or flue gases to the medium to be heated. 3.20 HEATING VALUE, GAS – The (Total) number of British Thermal Units produced by the combustion at constant pressure of 1 cubic foot of gas when the products of combustion are cooled to the initial temperature of the gas and air, when the water vapor formed during combustion is condensed, and when all the necessary corrections have been applied. 3.21 IGNITION SOURCE – a) Continuous – An ignition source that, once placed in operation, is intended to remain ignited or energized continuously until manually interrupted. b) Intermittent – An ignition source that is automatically ignited or energized when an appliance is called on to operate and that remains continuously ignited or energized during each period of main burner operation. The ignition source is automatically extinguished or de-energized when each main burner operating cycle is completed. c) Interrupted – An ignition source that is automatically ignited or energized when an appliance is called on to operate and that remains ignited or energized during the main burner flame- establishing period. The ignition source is automatically extinguished or de-energized when each main burner flame-establishing period is completed. 3.22 LINING – Those interior surfaces of a combustion chamber exposed to combustion during use of the appliance. 3.23 LIQUEFIED-PETROLEUM (LP) GAS – Fuel gases, including commercial propane, predominantly propane or propylene, or commercial butane, predominantly butane, isobutane, and/or butylene. 3.24 LP-GAS-AIR MIXTURE – Liquefied-petroleum gases distributed at relatively low pressures and normal atmospheric temperatures that have been diluted with air to produce desired heating value and utilization characteristic. 3.25 MANIFOLD – The conduit of an appliance that supplies gas to the individual burner.
3.28 ORIFICE – The opening in a cap, spud, or other device whereby the flow of gas is limited and through which the gas is discharged to the burner. 3.29 ORIFICE CAP (HOOD) – A movable fitting having an orifice that permits adjustment of the flow of gas by the changing of its position with respect to a fixed needle or other device. 3.30 ORIFICE SPUD – A removable plug or cap that contains an orifice and that permits adjustment of the flow of gas either by substitution of a spud with a different sized orifice or by the motion of a needle with respect to it. 3.31 PILOT – A small flame utilized to ignite the fuel at the main burner or burners. a) Continuous – A pilot that burns without turndown throughout the entire time the burner is in service, whether the main burner is firing or not. b) Proved – A pilot flame supervised by a primary safety control that senses the presence of the pilot flame prior to permitting the main burner fuel to be delivered for combustion.UL 307B-2009 pdf download.