Three MaterialsCPVC, GI and MS — each suited to a different job in the same house.
Three pipe materials. Completely different strengths. Use the wrong one in the wrong place and you will pay for it — in repairs, water quality, or replacement within 10 years. This guide settles it clearly.
If you are building or renovating a home and need to pick pipes, here is the summary — with details in every section below.
Every factor that matters for choosing the right pipe for your application — in one table.
| Property | CPVC (Ashirvad) | GI Pipes (Tata/Jindal) | MS Pipes (Jindal Star & Tata) |
|---|---|---|---|
| Material | Chlorinated PVC plastic | Mild steel + zinc coating | Mild steel (no zinc) |
| Corrosion resistance | Fully corrosion-proof | Rusts after 8–15 yrs internally | Rusts faster — needs coating |
| Max temperature | 93°C (hot water lines safe) | ~60°C (adequate for most use) | Up to 400°C (structural limit) |
| Max pressure | 1–2.5 MPa (pipe-size dependent) | Up to 10 MPa | Up to 15 MPa |
| Lifespan | 50+ years | 15–25 years (urban environment) | 15–20 years (with protection) |
| Water quality impact | Neutral — no taste/odour | Metallic taste when aged | Rust contamination without lining |
| Weight | Very light — easy to handle | Heavy | Heaviest |
| Installation | Solvent cement jointing — fast | Threading and coupling — slow | Welding or threading — slowest |
| Cost (½ inch, per metre) | ₹90–130 | ₹110–160 | ₹85–140 |
| Earthquake resistance | Flexible — absorbs movement | Rigid — joint stress at bends | Rigid — joint stress at bends |
| UV resistance | Needs protection if exposed to sun | Unaffected by UV | Unaffected by UV |
| ISI / BIS standard | IS 15778 | IS 1239 | IS 3589 / IS 1239 |
| Best application | Indoor water supply | Outdoor, overhead, gas, fire | Underground mains, industrial |
CPVC — Chlorinated Polyvinyl Chloride — is the result of an additional chlorination step that gives regular PVC the ability to handle hot water and higher pressures. For Indian homes, it is the clear recommendation for all internal water supply lines.
GI (Galvanised Iron) pipes are not obsolete. They are the correct choice for specific applications where their mechanical strength, rigidity, and metal properties are necessary.
GI pipes are mild steel pipes coated with a layer of zinc (galvanising) to resist corrosion. The zinc sacrificially corrodes in place of the steel, extending pipe life. In urban Indian environments with municipal water (which can be mildly acidic or contain chlorine), the zinc coating lasts 8–20 years depending on water quality. After this, internal rusting begins.
They are supplied in IS 1239 (Light / Medium / Heavy class) and IS 3589 grades. For domestic water supply, Medium class (B class) is the standard. For fire-fighting and heavy-duty, Heavy class (C class) is used.
Both Tata and Jindal are ISI-certified manufacturers with consistent quality. The choice between them is typically one of availability and price at your local supplier. Both meet IS 1239 specifications.
MS (Mild Steel) ERW (Electric Resistance Welded) pipes are the heaviest duty option in residential and commercial construction. They are not corrosion-resistant on their own, but they offer the highest pressure ratings and structural strength.
MS pipes are plain mild steel pipes without any corrosion-protection coating. They are sold as IS 3589 or IS 1239 (Heavy grade). For water applications, they must be coated internally (bituminous lining or epoxy) and externally (bituminous paint + wrapping for underground). Without protection, they rust rapidly in contact with water or moist soil.
A room-by-room and application-by-application guide for every situation in a typical Indian home.
| Application | Recommended Pipe | Grade / Size | Reason |
|---|---|---|---|
| Bathroom — shower, basin hot water | Ashirvad CPVC | ½" or ¾" | Hot water safe, no corrosion |
| Bathroom — toilet cistern (cold) | Ashirvad CPVC or UPVC | ½" | Cost effective for cold-only |
| Kitchen — water supply line | Ashirvad CPVC | ½" or ¾" | Food-contact safe, hot water |
| Solar water heater piping | CPVC (hot side) / CPVC (cold) | ¾" or 1" | Up to 93°C without joint failure |
| Overhead tank connections | GI — Tata/Jindal | 1" or 1½" | Supports tank weight, UV-stable |
| Terrace exposed water lines | GI — Tata/Jindal | ¾" to 1½" | UV and weather resistant |
| Gas supply (PNG / LPG) | GI — Medium Class (IS 1239) | ½" or ¾" | Metal pipe mandatory for gas |
| Underground water main (short) | GI — Medium Class | 1" to 2" | Buried, shorter runs |
| Underground water main (long) | HDPE or MS (coated) | 1" to 3" | Flexibility, long runs, no joints |
| Borewell column pipe (0–300 ft) | Ashirvad UPVC Column Pipe | 4" — 20G or 19G | Lightweight, no rust, easy removal |
| Borewell column pipe (300–500 ft) | Ashirvad UPVC Column Pipe | 4" — 19G (Light) | Max strength UPVC grade |
| Borewell column pipe (500+ ft) | GI Pipe | 4" Heavy | Column weight requires metal |
| Drain / soil / waste stacks | UPVC (SWR) | 75mm to 160mm | Purpose-designed for drainage |
| Structural column / pillar | MS ERW — Jindal Star / Tata | As per design | Structural — not water use |
| Fire-fighting riser | GI Heavy Class (IS 1239 C) | As per system design | Fire code requires metal pipe |
Material cost is only part of the equation. Labour, lifespan, and the cost of repairs when things go wrong all factor into the true total cost of ownership.
| Pipe Type | Material Cost (approx) | Labour Cost | Lifespan | 20-Year TCO (vs CPVC) |
|---|---|---|---|---|
| CPVC (Ashirvad) ½" | ₹90–130/m | ₹35–50/m | 50+ years | Lowest — no mid-life replacement |
| GI Pipe (Tata) ½" | ₹110–160/m | ₹55–80/m (threading) | 15–25 years | 20–30% higher — one replacement likely |
| MS Pipe ½" | ₹85–140/m | ₹70–100/m (welding) | 15–20 years | Highest — coating, replacement, repairs |
Many homebuilders save ₹15,000–30,000 by using GI instead of CPVC for concealed indoor plumbing. After 12–15 years, the GI rusts internally, reducing water pressure and contaminating the supply. Replacing a concealed GI pipe network in a finished home means breaking tiles, chipping plaster, cutting through concrete — and then redoing all of it. The repair cost is typically ₹80,000–3,00,000 and months of inconvenience. The original CPVC savings of ₹15,000 becomes a ₹2,00,000 liability.
GI pipe is not the wrong choice — it is the right choice in the right place. For outdoor exposed lines, overhead tanks, and gas supply, GI's rigidity, UV resistance, and metal properties make it the correct specification. The problem is only when GI is used as a cost-cutting substitute for CPVC in concealed indoor supply lines — where it has clear disadvantages and higher long-term cost.
Talk to Abhay at Nova Trading — CPVC · GI · MS · Column Pipes — all in stock at Secunderabad
Old Ghasmandi, Ranigunj, Secunderabad 500003 · +91 91009 29245