AS NZS 5263.1.2 pdf download

AS NZS 5263.1.2 pdf download.Gas appliances Part 1.2: Gas fred water heaters for hot water supply and/or central heating
1.3  Terms and definitions
For the purposes of this Standard the terms and definitions given in AS/NZS 5263.0 and the following apply. 1.3.201 automatic heat exchange water heater appliance in which water is heated by passing it through a heat exchanger immersed in heated water 1.3.202 central heating boiler appliance that is designed to heat and supply water at a temperature not exceeding 99 °C for hydronic heating purposes 1.3.203 circulator water heater in which water passes to a storage tank after heating Note 1 to entry: In the case of hydronic heating systems the term “circulator” might refer to a pump. 1.3.204 combination appliance appliance that is designed to perform the functions of both a central heating boiler and a water heater by means of two separate water circuits Note 1 to entry: Combination appliances are also known as combi boilers. 1.3.205 control thermostat preset device enabling the water temperature to be maintained automatically, within a given range 1.3.206 drain valve valve in the bottom of the water vessel, through which the water may be drained from an appliance 1.3.207 expansion relief valve pressure actuated valve that automatically discharges water at a specified set pressure to prevent the pressure in the system exceeding the maximum working pressure during normal operation 1.3.208 heat output amount of heat transferred to the water per unit time under specified conditions Note 1 to entry: Heat output is expressed in kilowatts (kW). 1.3.209 hydronic relating to a system of heating or cooling that involves the transfer of heat by circulation of a fluid (usually water) in a closed circuit Note 1 to entry: The closed circuit in a hydronic system may be vented or unvented.
1.3.210 instantaneous water heater water heater or central heating boiler in which gas, except for any pilot flame, burns only when water is discharged from the outlet of the appliance 1.3.211 maintenance gas consumption gas consumption required to maintain at a steady value some particular condition in an appliance Note 1 to entry: For a storage water heater, the maintenance gas consumption is determined for steady water temperature. 1.3.212 maximum working water pressure pressure setting of the water pressure relief valve or its equivalent 1.3.213 minimum working water pressure minimum water supply pressure required to operate the appliance at its stated performance 1.3.214 range rated appliance appliance with installer adjustable nominal heat input to suit the heat requirements of the installation 1.3.215 relief device safety device designed to forestall the development of a dangerous condition by preventing pressure, temperature or vacuum build-up 1.3.216 safety temperature limiter device that causes safety shutdown and non-volatile lock out so as to prevent the water temperature exceeding a preset limit 1.3.217 storage capacity quantity of water contained within the storage vessel of a storage water heater Note 1 to entry: Storage capacity is measured in litres (L). 1.3.218 storage water heater water heater that incorporates a thermally insulated container in which the water is heated and stored for subsequent use 1.3.219 temperature sensing element component that detects the temperature of the medium to be supervised or controlled 1.3.220 water heater appliance that is designed to heat and supply water at a temperature not exceeding 99 °C for drinking and/or sanitary purposes 1.3.221 water operated gas valve gas valve actuated by a flow or change of pressure in a water system of an appliance 1.3.222 water pressure relief valve pressure actuated valve that automatically discharges fluid at a specified set pressure Note 1 to entry: A water pressure relief valve is fitted to a water heater to prevent the pressure in the water carrying parts from exceeding the maximum working pressure during normal use, and from exceeding a predetermined margin over the maximum working pressure when temperature controls fail to limit pressure.