Plumbing glossary: M
Got an appointment with a plumber? Use our plumbing glossary to hold the conversation.
M tubing – an industry standard for copper tubing defined by the tube wall thickness and identified by a red stripe
MC Tank – acetylene tank holding 10 cu.ft. of gas, once used to fuel motorcycles and now used for plumbing
MCL – Maximum Contaminant Level – the maximum level of a contaminant allowed in water by law, which is based on potential health risks and what treatment is readily available
MHT – Male Hose Threads – the threads on the outside of a connection
MIPC – Male Iron Pipe Connection – standard external threads on pipe and fittings
MPN – Most Probable Number – term used to indicate the number of organisms that, according to statistical theory, would be most likely to produce the results observed in certain bacteriological tests – usually expressed as a number in 100 ml of water
Macerator – a device installed in a drain line between a toilet and the soil stack to reduce solids to liquid form
Magnesium – an element in the Earth’s crust that makes water hard when dissolved, causing scale and insoluble soap curds
Main – the primary artery of water supply in a drain system
Male fitting – fitting that is inserted into another fitting
Malleable fittings – fittings made of cast iron, a metal which is soft and pliable
Manganese – an element sometimes found dissolved in ground water that causes black stains
Manhole – access opening to a hole, usually with a cover, through which a person may enter a sewer, boiler, drain, etc. – it’s usually round to prevent the cover from falling into the opening
Mapp gas – a colourless, flammable gas made by combining liquefied petroleum gas with Methylacetylene-Propadiene – it is a stable, non-toxic fuel used for brazing and soldering
Meter tailpiece – an adapter connecting a water meter to the water supply line
Mission coupling – a neoprene flex coupling, connecting PVC to PVC, or clay to PVC
Mixing valve – mixes hot and cold water to achieve a specified delivery temperature
Monobloc faucet – a single-handle faucet, usually a lever
Multi-port valve – rotary type backwash valve, which can replace up to six regular gate valves
Multi-stage pump – a pump that has more than one impeller
Municipal water – water supplied by a city for public use
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