It is quite important for a professional plumber to check before he buys or installs any material that it complies with either the British or European Standard specification. The British standard spec however is just a guide and hold no lawful influence. The plumbing profesional will work on all fittings and systems, like, Hot and Cold Water, Central Heating, Sheet lead weathering, above ground drains and below ground rrains (for connection only). The plumber will also work with a varying range of materials that are used for system pipework, fittings and components, these include: Copper, lead, plastics, ceramics, steel and brass. It is very important that the beginner has a good knowledge of the properties of these materials and their suitability for the jobs that they are employed . Hampstead Plumbers will only supply qualified tradespeople to work on plumbing jobs. Think for a moment how it would be if you could buy a huge range of 15mm fittings that all had a slightly different inside diameter to the external diameter of a15mm pipe. The job would be very time consuming and almost impossible to do correctly. A Hampstead Plumber is a qualified fully trained professional tradesperson. The BSI kitemark is only used only on materials and equipment that meet the high standards of the British Standards Institution (BSI), who oversee and administer the standards for all goods in the UK. The British Standard Institute upholds high standards of quality and it also sets standard dimensions for pipes and fittings. The British Standards all begin with the letters BS and is followed by the given number of the standard. For instance, BS 1566-1 and BS 1566-2 are related to copper cylinders used for domestic purposes, and double and single feed indirect cylinders. “