How we supply it: CPVC pipes and fittings are arranged through a partner plumbing dealer who quotes, supplies and bills them and pays us a referral commission. Send your plumber's material list; the pipes arrive before the brickwork reaches lintel level so concealed lines go in before plastering.
In one line: CPVC (chlorinated polyvinyl chloride) pipe is a rigid plastic pipe whose extra chlorine lets it carry hot water safely, joined with solvent cement made for CPVC.
CPVC, uPVC or GI?
| Point | CPVC | uPVC | GI |
|---|---|---|---|
| Hot water | Yes, commonly rated up to about 93 °C | No | Yes |
| Corrosion and scale | None | None | Rusts and scales inside |
| Joints | Solvent cement | Solvent cement or ring | Threaded |
| In sunlight | Needs protection | Needs protection | Paint for rust |
| Typical use | All hot lines, concealed bathroom lines | Cold mains, pump delivery, garden | Rarely used in new houses |
What makes CPVC different
CPVC (chlorinated polyvinyl chloride) pipe is a rigid plastic pipe whose extra chlorine lets it carry hot water safely, joined with solvent cement made for CPVC. In India it is made to IS 15778.
It expands more than metal pipe when hot. Long hot runs need clamps that let the pipe move and offsets at changes of direction.
Classes, sizes and fittings
| Item | What it means | Where |
|---|---|---|
| SDR 11 | Thicker wall for its outside diameter | Hot lines, pumped supply |
| SDR 13.5 | Thinner wall | Cold, low-pressure lines |
| ½ inch | Branch size | Individual taps |
| ¾ and 1 inch | Main and riser sizes | Downtakes from the tank, mixer feeds |
| Brass-threaded adaptors | Plastic-to-metal transition | Valves, mixers, geyser connections |
Laying concealed lines
- Mark all outlet points on the walls before chasing.
- Cut pipes square, deburr and chamfer the ends, and dry-fit the run.
- Apply CPVC solvent cement to pipe and socket, push in with a quarter turn and hold briefly.
- Clamp exposed runs, sleeve pipes where they pass through walls, and leave room for expansion on hot lines.
- Pressure-test the whole system at the test pressure the plumber specifies, typically above working pressure, and inspect every joint before closing the chases.
Material and joint checks
- The pipe print should show IS 15778, the SDR class, size and batch.
- Fittings and solvent cement must be labelled for CPVC, not uPVC.
- Look inside a few fittings for cracks and flash left from moulding.
- Watch one joint being made: square cut, chamfer, cement on both parts, full push.
- Check the pressure gauge holds steady for the test period before plastering.
Storing pipes and cement
- Keep pipes in shade; months of sunlight make plastic brittle.
- Store them flat and fully supported so they do not set bent in the heat.
- Keep solvent cement tins tightly closed; thickened cement makes weak joints.
Plumbing mistakes with plastic pipes
- uPVC on the geyser or solar-heater outlet.
- uPVC solvent cement on CPVC joints.
- Exposed CPVC on the terrace without paint or sleeving.
- Tiling before the pressure test.
- Threading plastic straight into metal valves without brass adaptors.