GI pipes rust in 5–7 years. CPVC pipes carry hot water for 50+ years without scale. Here's why every modern Indian home uses CPVC for hot water lines.
For two generations Indian homes used GI (galvanised iron) for hot water plumbing. Today GI is almost extinct in residential projects — replaced by CPVC. This article explains exactly why.
Temperature Rating
CPVC is rated for continuous service up to 93°C — well above the 60–70°C delivered by a typical home geyser. GI fails progressively above 60°C due to thermal stress on the galvanised coating.
No Rust, No Scaling
GI corrodes from inside out. Within 5–7 years the bore narrows, water pressure drops and the reddish-brown rust contaminates drinking water. CPVC is inert — water quality is the same on day 1 and year 25.
Lower Heat Loss
CPVC has thermal conductivity nearly 300 times lower than steel. Hot water reaches the tap warmer and the geyser cycles less often — measurable savings on electricity bills.
Easy Installation
CPVC weighs a fraction of GI, joins with solvent cement in seconds, and needs no threading machine. A plumber installs 3–4× faster than with GI.
Indian Standard
Always specify CPVC pipes and fittings manufactured to IS 15778. The ISI mark is printed every metre.
Frequently Asked Questions
What temperature can CPVC pipes handle?
CPVC is rated for continuous service at 93°C and intermittent peaks higher than that — well within the safe range for any household geyser.
Is CPVC safe for drinking water?
Yes. CPVC pipes manufactured to IS 15778 are NSF/ANSI-style approved for potable hot and cold water.
How is CPVC joined?
CPVC is joined with a one-step CPVC solvent cement specifically formulated for chlorinated PVC. Curing is complete within an hour for most diameters.
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.