Home > Knowledge > Content
What is the difference between P trap and S trap?
Nov 13, 2018

A trap is length of pipe with a curve that bottoms out with a "P", "S" or “U” shape. The curve holds a pool of water that seals out gases rising from the sewer. 

If we look under any sink, we will see a curved pipe connected to the drain. In most cases, the P trap with a horizontal section that runs into the wall, where the drain is located. In some instances, however, the drain pipe rises up from under the sink, S trap will be used to connect to drain.S trap curves down, then up, then down again, it connects to the drain pipe in the floor.


The only difference between a P trap and an S trap is the horizontal length of pipe on the outflow side which is connected the vent. 

timgtimg (1)

However, it is possible that gases backflow from sewer when the trap may dry out. Usually this happens because the drain hasn’t been used in a while, or is faulty. In most cases, flowing water into the drainage is enough to refill the trap and stop the stink. However, if the pipeline is faulty or damaged, it is suggestion to replace the piping by professional plumber.

Another function of traps is that they also tend to collect any small but heavy object that may accidently get dropped down the drain( e.g. ring, necklace etc.). The object gets stopped at the curve and is hard to flush down unless with extreme force. The curve also stacks hair, sand, and other debris hence stopping them from passing into the rest of the plumbing, which may result in a blockage. 

Related Industry Knowledge

24 hours at your service:



Copyright © Guangdong Swin Plastic Industrial Co.,Ltd All Rights Reserved.