Types of Traps in Plumbing and Their Functions

What Is A Plumbing Trap?

A plumbing trap is a device in a plumbing system that traps a small amount of water in a bend in a pipe to prevent sewer gases from escaping into a building.

The water in the trap creates a seal that blocks the flow of gases, preventing them from entering the building through drain pipes.

Traps are typically located in the drain lines of fixtures such as sinks, toilets, showers, and bathtubs, and are an important component of a plumbing system as they protect the health and safety of building occupants by preventing the release of harmful gases into the living spaces.

These plumbing Traps come in various shapes and sizes, but the most common design is the P-trap, which is shaped like the letter “P” and is commonly used in residential and commercial plumbing systems.

Read More: 16 Plumbing Fittings Types With Their Application & Pictures

Plumbing Trap Types

The types of traps in plumbing are as follows,

  1. Gully Trap
  2. P Trap
  3. S Trap
  4. Q Trap
  5. Floor Trap / Nahni Trap
  6. Bottle Trap
  7. Intercepting Trap
  8. Running Trap
  9. Drum Trap
  10. Straight-Through Trap
  11. Low-Level Bath Trap
  12. Building Trap
  13. Bell Trap
  14. Grease Trap

1. Gully Trap

Gully Trap
Types of Traps in Plumbing and Their Functions 9

These plumbing traps are built external to the building to carry wastewater released from sinks, washbasins, restrooms, and so on, and are associated with the most nearby building drain or sewers so that foul gases from the sewer don’t go to the house. These are profound seal traps.

In Gully Traps profundity of the water seal ought to be at 50 mm at least. It additionally keeps cockroaches and different bugs from sewer lines to squander pipes carrying wastewater. Gully traps are available in the following three shapes:

  • P Trap
  • S Trap
  • Q Trap

2. P Trap

P Trap
Types of Traps in Plumbing and Their Functions 10

This trap is utilized with the Indian water closet (ORISSA Pattern). The traps are produced using cast iron or UPV sheet. This trap likewise has a water seal and forestalls a section of foul gases in the house. 

3. Q Trap

Q Trap
Types of Traps in Plumbing and Their Functions 11

These plumbing trap types are utilized in the latrine-submerged storage room. It is practically like an S trap and is being used in the upper story other than the ground floor. 

4. S Trap

S Trap
Types of Traps in Plumbing and Their Functions 12

This plumbing trap types are like a P-shaped trap and is utilized for fixing water closets in latrines. The lone contrast between the P trap and the S trap is that the P-shaped trap is being used for an outlet through the wall while the S-shaped trap is utilized for an outlet through the floor.

5. Floor Trap | Nahni Trap

Floor Trap/Nahni Trap
Types of Traps in Plumbing and Their Functions 13

The floor traps are additionally called Nahni Traps. Nahi Trap is given to forestall the foul gasses going into the building by providing the water seal.

At least 50 mm profundity of water seal ought to be given. If squander water is streaming, a floor trap forestalls the foul gases (awful stenches) to enter the building.

To gather wastewater from the bathroom, wash zone, washbowl, kitchen sinks, and so on, a floor trap or Nahni trap is provided into the floor. Floor traps are accessible in PVC, UPVC, and CI; they are without vent pipes, yet removable grinding is shown at the Traps’ highest point.

Floor traps or Nahni traps (Nahni implies washing place) arrive in an assortment of shapes, sizes, and outlet conditions.

Many don’t have a water seal by any stretch of the imagination and have a non-uniform and unpleasant bore.

Nahni traps are a wellspring of significant spillages because of their helpless plan, projecting, and low quality.

It is forestalled by utilizing just profound seal P traps with multi-gulf fitting/traps with associations from washbowls and other fitting to give a positive joint.

These plumbing trap types are introduced in regions that may lose their water seal because of dissipation. The arrangement should be made to re-establish the seal by adding water intermittently.

This should be possible by associating a waste apparatus to the trap (for example, a washbowl, and so forth).

Likewise, recharging is accomplished by introducing a refined water supply valve with a reverse avoidance gadget associated with the trap. Care must be taken to forestall the establishment of traps that are presented to freezing conditions.

The floor trap’s length is 310 mm, with at least 80 mm distance across at the channel end, 30 mm width close to the outlet end, and 73 mm breadth outside the floor trap outlet. 

What’s more, 95 mm grinding size gave the highest point of floor trap with 8 mm measurement openings.

Read More: 75+ Construction Tools Name and Their Uses with Image

6. Bottle Trap

Bottle Trap
Types of Traps in Plumbing and Their Functions 14

A bottle plumbing trap is given to get squander from the washbasin, kitchen sinks, and different machines where the apparatuses don’t have an underlying trap.

7. Intercepting Trap

Intercepting Trap
Types of Traps in Plumbing and Their Functions 15

Intercepting plumbing trap types are given into the Interceptor Manhole (Interceptor Chamber). An Interceptor sewer vent is provided at the interference of building sewer and Public sewer.

That blocking type of trap is given to keep the foul gases from public sewers entering the building sewer by providing a water seal.

8. Grease Trap

Grease Trap
Types of Traps in Plumbing and Their Functions 16

A grease trap is introduced in the waste line from at least one installation to isolate grease from the fluid and hold it.

This kind of trap is a gadget to gather the grease substance of waste and can be cleaned from the surface. This is mostly utilized in the food handling unit.


There are numerous sorts of plumbing trap types: Intercepting Trap, Floor Trap or Nahni Trap, Gully Trap, P Trap, Q Trap, S Trap, Bottle Trap, and Grease Trap. They are accessible in various materials like PVC, GI, and so forth. 

Previously mentioned kinds of traps are broadly utilized in pipe work, yet ideal pipes traps have the following highlights or advantages

  • Simpler and speedy establishment 
  • Longer service life 
  • Protection from the effect of harm and household substance 
  • Forestall section of foul air, insects, and parasites from the sewers 
  • It is against rats and self-cleaning. 
  • Conservative 

On the off chance that you need your home liberated from the foul smell, bugs, and parasites, utilize the appropriate and the best kind of plumbing traps. This isn’t just effectively and quickly introduced, yet it welcomes less weight on your pocket as well.


In conclusion, understanding the various types of trap in plumbing and it is essential for maintaining a hygienic system and functional system. The traps serve as vital components which prevent foul odour, harmful gases and pests from entering our living spaces.

P-traps are the most common types and it typically found under sinks, providing a water seal which blocks sewer gases from flowing back into the building, S-traps, on the other hand, are less commonly used due to their tendency to siphon out the water seal, leading to potential odour and health hazards.

Bottle traps are compact and versatile, often employed in tight spaces or to aesthetic purpose, and it is crucial to choose the appropriate t rap based on plumbing requirements and building codes.

Regular maintenance, including cleaning and inspection, will help ensure the traps continue to function effectively, by understanding the various types of traps and their specific functions, plumbers and homeowners can help to prevent plumbing issues and promote a healthy and clean environment.


You May Also Like:

Share This Post

Leave a Reply

Download Construction Excel Sheet

Popular Post on Website

Scroll to Top
DMCA.com Protection Status