Test your vocabulary with our -question quiz! Michael kelly, ashford, co wicklow. For smaller diameter pipework over standard distances, we use colour pipe tv inspection systems for surveying pipe diameters from mm through to mm this system has features like on-screen text and auto on-screen meterage readout. As british gas is the market-leading boiler installer in the uk, i decided to get a quote from them as a starting point. Preview: baxi wall-hung gas boiler helps.