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Last edited 03 Nov 2022
Types of waste trap
 What are waste traps?
Waste traps or traps are small plumbing devices designed to prevent odours from sewage or waste water leaving the pipe systems and entering the interior spaces of buildings. They can also help prevent the spread of bacteria and insects.
They are simple but ingenious devices that generally work by creating an air trap using the waste water of the system, which sits in a small reservoir within in the line of the waste water flow. It is normally a relatively simple plumbing part used in sinks, toilets, showers, baths as well as floor level drains, coming in a variety of types with various terms associated.
 Types of waste trap
Some of the more common types of waste trap are described below.
The U-bend is possibly the most common term used to describe a waste trap in the UK. The variations on this type all contain a U shaped form in their design. The U trap was invented by the English businessman plumber T.Crapper in the late 1800's and was an improvement on the S trap which was invented some 100 years earlier.
A floor or nahni trap is a shallow design of minimum 50 mm depth provided in the floor to drain and prevent smells entering internal spaces. Nahni is indian for washing area, where these are commonly used.
Interceptor traps normally act between the main sewer and building sewer, they have deep water seals of 100 mm to prevent bugs and insects crossing systems and are usually found in the outlet of the last manhole chamber from a property before the main sewer connection and are typically made of vitreous clay. There are many different types such as: The Winser trap, Kenon trap, Bristol trap, Buchan trap, Reverse Interceptor trap, The Radnor, The Netley (reverse action), The Warwick, The Coulsdon and The Salus.
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