ABSTRACT
The gas meter and its associated controls are the property of the gas authority. It should be sited as close as possible to the service pipe entry to the building, ideally in a purpose-made meter cupboard on the external wall. When used with a flexible tube, hand bellows and control cock, 'U' Gauge equipment is suitable for measuring gas installation pressure and testing for leakage. The control box houses an air intake, electronic controls, gas regulators and safety cut-out mechanisms. The shunt duct system is applicable to the installation of several conventional appliances with open flues in the same building. For correct combustion of natural gas, burner design must allow for the velocity of the gas-air mixture to be about the same as the flame velocity. Natural gas has a very slow burning velocity, therefore there is a tendency for a flame to lift-off the burner. Mains gas pressure is low compared with mains water.
