SWR pipes carry every drop of waste and rainwater out of your home. Here's how to specify them correctly so you never hear a gurgle or leak.
SWR stands for Soil, Waste and Rainwater. PVC SWR pipes are the standard for above-ground drainage in Indian residential, commercial and institutional buildings — replacing cast iron almost completely.
Indian Standard: IS 13592
IS 13592 covers PVC pipes for SWR applications. The standard specifies two types based on stiffness:
Type A: lower stiffness — for ventilation and rainwater downtake pipes.
Type B: higher stiffness — for soil, waste, drainage and underground use.
Common Sizes
75 mm — kitchen and basin waste.
110 mm — soil and waste stacks for WCs.
160 mm — large soil stacks and rainwater downtakes for big buildings.
Joining: Ring-Fit vs Solvent
SWR pipes are joined either with rubber-ring sealed sockets (ring-fit) or with solvent cement. Ring-fit allows thermal expansion and is preferred for vertical stacks; solvent joints are common for branch lines.
Why PVC SWR Replaced Cast Iron
Cast iron drainage was heavy, rusted, and amplified water noise. PVC SWR is lighter, doesn't corrode, installs in a fraction of the time, and dampens flow noise significantly.
Frequently Asked Questions
What is the difference between SWR Type A and Type B?
Type A has lower ring stiffness and is used for ventilation and rainwater downtakes. Type B has higher stiffness and is used for soil, waste and underground drainage.
What size SWR pipe do I need for a WC?
Standard practice in India is to use 110 mm SWR pipe for the WC soil line and connecting stack.
Can SWR pipes be used underground?
Type B SWR pipes can be used in shallow underground drainage. For deeper or high-load applications, use PVC underground sewer pipes or DWC pipes.
Reviewed by
Sahil Jindal
Managing Director, Jindal Composite Tubes Pvt Ltd
3rd-generation pipe manufacturer with 25+ years of hands-on experience in PVC, CPVC and UPVC pipe engineering, ISI/BIS compliance and India-wide plumbing distribution.