It is a pipe fitting that holds water to prevent entry of sewer gases. A Trap or Return is a U or S shaped equipment that inverses the direction of the pipe. Flexible trap and standard trap is an absolute solution for smelly and clogging basins, tanks, sinks etc and provide the plumber with easy to install and practical products. They are used to prevent the passage of sewer gas from the plumbing system into house through the plumbing fixture drain.

Return or pipe trap falls under the head of " Tubular products" along with other fittings that are found under sinks and connect them to the drainage lines. Tubular products are manufactured in a sizing standard that is neither compatible with IPS pipe nor with CTS tubing. These products are made in tube sizes, but the threads used on them are incompatible with other products. They are adjustable, easily removed for repairs or cleaning, and can be assembled without making precise measurements and cuts.

Every open drain requires a trap to be installed below it to prevent sewer gas from escaping into the house. This trap is always full of water. The specific configuration of the trap depends on the type of sink under which it's installed and the location of the drainage pipe to which it connects.

There are a wide variety of trap fittings available to accommodate nearly any situation one might encounter. Some of the popular types of trap available in the market are: