Drainage Pipe

Last updated: October 2026 | Reviewed by the Ajay Pipes technical team

A drainage pipe carries waste water, rain water or excess ground water away from a building or a site. Every home, road and factory depends on one. A weak pipe leads to blocked sinks, bad smells and damp walls. This guide explains the main types of drainage pipes, their sizes and their best uses, so you can choose the right one for your project.

Where Do You Use Drainage Pipes?

Drainage pipes serve many jobs. Each job needs a different pipe type.

• House drainage: pipes take waste water from sinks, showers and toilets to a sewer or septic tank.
• Rain water drainage: pipes collect roof and road run-off and send it to storm drains.
• Underground drainage: pipes link a building to the main sewer line.
• Agricultural drainage: pipes remove extra water from fields, which protects crops from waterlogging.
• Industrial drainage: pipes carry effluent away from plants and workshops.

Water seals in the traps stop sewer smells from entering the room. As a result, a well-built system stays quiet and odour free.

What Are the Main Types of Drainage Pipes?

Several materials compete in this space. The table compares them at a glance.

PVC pipes lead the market for homes and buildings. They are light, they resist corrosion, and they join with a rubber ring or solvent cement. Therefore, they save time on site and keep costs low.

What Are SWR Drainage Pipes?

SWR stands for soil, waste and rain water. These pipes handle the discharge from toilets, sinks, showers and roof gutters in a building. They run by gravity, so the pipe needs a steady slope toward the outlet.

Ajay Drainline SWR pipes come in 75, 90, 110 and 160 mm sizes. Each size comes in Type A and Type B wall thicknesses. The pipes follow IS 13592, and the fittings follow IS 14735. You can pick ring-fit joints for quick fitting or solvent-fit joints for a fixed bond. The grey pipes also resist mould and fungus growth, which keeps the inner wall clean.

Traps matter as much as pipes. A nahani trap needs a water seal of at least 10 mm, and a P-trap needs at least 50 mm. A proper seal blocks foul gas from the sewer.

What Are UDS Pipes?

UDS means underground drainage system. These pipes link the drains of a building to the main sewer or storm line. They carry heavy soil loads, so strength matters more than it does above ground.

Ajay Terraline UDS pipes use a foam core design. A foamed PVC layer sits between a solid inner layer and a solid outer layer. This build makes the pipe about 25% lighter than a solid wall PVC pipe. The terracotta colour makes buried pipe easy to spot, and the pipe resists rodent damage. The pipes follow IS 16098 (Part 1) and come in three ring stiffness classes.

• SN2: for light soil loads and shallow depths.
• SN4: for general use under gardens and low-traffic areas.
• SN8: for deeper trenches and heavier loads.

The pipe handles chemicals between pH 2 and pH 12, so it also suits many effluent lines. Ajay designs the system for a 50 year life.

How Do You Choose the Right Drainage Pipe?

Match the pipe to the job with these checks.

1. Decide where the pipe will run. Use SWR pipes inside a building and UDS pipes underground.
2. Pick the size from the number of fixtures. A toilet line usually needs 110 mm, while smaller fixtures can use 75 or 90 mm.
3. Choose the wall type or ring stiffness from the load. Deeper trenches need stiffer pipes.
4. Confirm the standard number on the pipe. IS 13592 covers SWR pipes, and IS 16098 covers UDS pipes.
5. Select the joint type. Ring-fit joints allow easy movement, and solvent-fit joints give a rigid bond.

You can also verify licence details on the Bureau of Indian Standards website before you buy.

How Do You Maintain a Drainage Pipe System?

Good care prevents most blockages and leaks.

• Keep grease, hair and solid waste out of the drains.
• Flush traps with water in rooms you rarely use, so the water seal stays full.
• Clean inspection chambers on a regular schedule.
• Leave a 10 mm expansion gap in ring-fit joints.
• Fix slow drains early, before the blockage grows.

Conclusion

The right drainage pipe depends on location, load and flow. Choose SWR pipes for building lines and UDS pipes for underground runs. Always check the standard marking and the joint type before you order. For technical help or a quote, call toll free 1800 11 4050 or email enquiry@ajaypipes.com.