14 Type of Trap in Plumbing

Plumbing Trap

What Are Traps in Plumbing?

A plumbing trap is a plumbing sanitary system. which prevents harmful gases from entering the house. The trap is designed to be continuously filled with water.

It is important to keep these types of traps to keep the environment fresh. This type of trap prevents dirty air from entering the house.

Drain lines are made to drain water into every appliance or fitting in the house that uses water. Its connection is to the main sewer. So there should be a trap in the pipe, through which the drain can be sealed. The gully trap is fitted with a mesh to prevent debris. The height of the water seal in the gully trap is kept at 60 to 70 mm.

Plumbing traps are made of good quality. A bent pipe is used to obtain a water seal in any trap. You may have seen different types of design traps in your home plumbing fittings like floor trap, alley trap, p-trap, etc.

Specification of Plumbing Trap

  1. The trap should be made of good material for proper reinforcement.
  2. The trap should be properly filled with water so that harmful gases do not enter the house.
  3. The inside surface of the trap should be smooth so that water can escape easily.
  4. The quality of the trap should be good so that the water clears itself.
  5. The trap should not have grooves and its surface should be smooth so that water can be easily drained.
  6. Trap design should be simple and cost-effective.
  7. The trap should be easily fitted with the drain.
  8. The gully trap is fitted with a mesh to prevent debris. The height of the water seal in the gully trap is kept at 60 to 70 mm.

14 Type of Trap in Plumbing

There are many different plumbing trap types commonly used. Which are as follows

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

1. Gully Trap

Gully Trap

The gully trap is known as the GT trap.  The plumbing trap collects water from the kitchen and washing basin. And from there it connects to the main sewer line. Thus the gully trap serves to connect the lines of the house to the sewage line.

The gully trap is fitted with a mesh to prevent debris. The height of the water seal in the gully trap is kept at 60 to 70 mm. For proper connection and installation of alley traps, you can usually dig less than 1 foot below the ground.

The water seal should be at least 50 millimetres for the integrity of the water seal in alley traps. So that insects and dirty gases can be prevented from entering your house. These traps are made in different places in different drain pipes.

Also Read: What Is Isometric Projection? | Principle of Isometric Projections | Isometric Scale | What Is Isometric Drawing? | Methods of Isometric Drawing

2. Floor Trap

Floor Trap

Floor traps are installed at the bottom in sinks, bathrooms, and kitchens. Water from the floor trap goes into the outer chamber through the sewage line. The water seal in the floor trap is small.

It is used to collect wash water from the floor, kitchen, and bathroom. it is made of cast iron, PVC material.

3. P-Trap


P-traps are commonly used in top floors and wall-mounted toilets. In addition, P-trap is used more in kitchens and laundry sinks. P-trap is made of PVC material.

4. S-Trap


S trap is used in floor mount-type toilets. This plumbing trap is also used in sinks and wash basins. S trap is used to prevent harmful gases from entering the house.

5. Q-Trap


Q trap is used in the toilet underwater closet. It is used in the upper story other than the ground floor.

6. Intercepting Trap

Intercepting Trap

Intercepting trap is provided at the junction of the house drain with the public septic tank. This trap carries water to public sewage. This trap is known as the last drainage system of the house.

These types of traps are arranged in an inspection chamber. It is cleaned by an inspection chamber.

7. Bottle Trap

Bottle Trap

Bottle Trap Sink has a larger diameter than the plumbing pipe that comes from the basin. When water is poured in, the trap is filled with fresh water. Thus, the trap is filled with some amount of water.

Also Read: What Is Lean to Roof? | Composition of Lean to Roof | Important Notes for Construction of Lean to Roof | Advantage & Disadvantage of Lean to Roof | Roofing Materials Suitable for Lean to Roof

8. Grease Trap

Grease Trap

This type of trap is used in the drainage system of restaurants, hotels, and industries

This type of trap requires a place where large quantities of oily substances are used.

If this oil is not removed it gets stuck in the pipe of the drainage system. It damages the pipe from the inside.

Vegetable oils and animal fats are 10 per cent lighter than water and it cannot be mixed with grease. Thus, fat and oil float on top of the water. The grease trap works on this principle.

A grease trap is a chamber made of cast iron or masonry work.

9. Running Trap

Running Trap


The trap is arranged in a pipe that allows fluid to flow. So as to obstruct the gases coming from the drain.

10. Drum Trap

Drum Trap


A drum trap is placed under the washbasin. The shape of the drum trap is cylindrical. Which can be opened for cleaning by the floor plate or from below.

11. Straight Through Trap

Straight Through Trap

This type of trap has a 1¼ “inlet and outlet. This type of trap also includes a cleaning eye. It has a 75 mm water seal. This type of trap is made from polypropylene.

This type of trap allows neat plumbing for inlet and outlet connections.

12. Low-Level Bath Trap

Low-Level Bath Trap

The low-level bath trap has a 38mm seal. Thereby providing a water seal between the wastewater pipe and the interior of the room.

It prevents the odor coming from the manhole from re-entering the room through the pipe. The 38 mm water seal contains water that acts as a barrier. It also has an access pipe for overflow.

Also Read: What Is Modified Proctor Test? | Purpose of Modified Proctor Test | Modified Proctor Compaction Test Apparatus | Modified Proctor Test Procedure | Calculation of Modified Proctor Test | Difference Between Standard Proctor Test  Vs Modified Proctor Test

13. Bell Trap

Bell Trap


Bell traps are used in drains, garages, patios, or other outdoor.

It has a water seal-like any other trap.

14. Building Trap

Building Trap

The water seal in this trap is a U-shaped piece of pipe designed for unwanted gas.

Building traps are essential in every home in every building.

Like this post? Share it with your friends!

Suggested Read –

Frequently Asked Questions (FAQ)

What Is a Plumbing Trap?

A plumbing trap is a crucial component in a drainage system that retains a small amount of water to prevent foul gases and sewer odors from entering a building. It also helps to stop pests from entering through the pipes.

Why Are Traps Necessary in Plumbing?

The purpose of the p-trap is to catch water in the dip in the pipes and keep it there. After you run water down the drain, gravity will keep a plug of water in the dip. (The maximum trap seal depth is 4”.) This plug blocks the odors of decaying sewage from wafting up from the wastewater system and into your home.

What Are the Common Types of Traps Used in Plumbing?

  1. P-Trap: Shaped like the letter “P,” it’s commonly found under sinks and basins.
  2. S-Trap: Resembles the letter “S” and is often used when the drainage pipe is vertical.
  3. U-Trap (or U-Bend): Similar to the P-trap but has a longer horizontal section, forming a U-shape.
  4. Bottle Trap: Compact and space-saving, often used in contemporary plumbing for aesthetic reasons.

What Are S and P Type Traps?

S-trap, only instead of going down-up-down to create an S-shape, it goes down, curves up, then becomes straight, creating an open P-shape. That’s a P-trap! More commonly installed in top floors and in wall-mounted toilets, P-traps are more commonly used in kitchen and laundry sinks.

What Is the Difference Between P-Trap and J Trap?

J Trap vs. P Trap. The primary difference between a J trap and a P trap lies in their shape and configuration. While both traps serve the same purpose of preventing sewer gasses from entering your living space, they have distinct designs that are suitable for different plumbing scenarios.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top
Scroll to Top