A borewell rising main carries water from the submersible pump at the bottom of the borewell to the surface. It faces extreme conditions: high discharge pressure, continuous vibration from the pump, thermal cycling, and the weight of the water column above. Choosing the right pipe is critical.
Why HDPE Is the Best Choice for Borewells
| Factor | HDPE | GI Pipe | PVC |
|---|---|---|---|
| Corrosion | None — zero rust | Rusts from inside and outside | None |
| Weight | Very light (1/8th of GI) | Very heavy | Light |
| Flexibility | Handles vibration well | Rigid — stress cracks at joints | Rigid — brittle |
| Joint type | Heat-fused (permanent) | Threaded (leak-prone) | Not suitable for borewell |
| Lifespan | 50+ years | 10–15 years | Not recommended |
| Installation | One person can install | Needs crane for deep wells | — |
| Bore reduction | None — smooth bore for life | Rust buildup reduces bore yearly | — |
Borewell Pipe Selection Guide
| Borewell Depth | Pump HP | Recommended OD | PN Rating | SDR (PE 100) |
|---|---|---|---|---|
| 30–60m | 1–3 HP | 50mm or 63mm | PN 10 | SDR 13.6 |
| 60–90m | 3–5 HP | 63mm | PN 12.5 | SDR 11 |
| 90–120m | 5–7.5 HP | 63mm or 75mm | PN 12.5 | SDR 11 |
| 120–150m | 7.5–10 HP | 75mm or 90mm | PN 16 | SDR 9 |
| 150–200m | 10–15 HP | 90mm | PN 16 | SDR 7.4 |
| 200m+ | 15+ HP | 110mm | PN 16–20 | SDR 7.4–6 |
Borewell Depth vs Required Pressure Rating
As depth increases, the hydrostatic pressure on the riser pipe increases. Choose a PN class that exceeds the depth-based pressure.
How to Calculate the Right Pressure Rating
- 1Static head = borewell depth in metres ÷ 10 = bar (e.g., 100m depth = 10 bar static)
- 2Pump discharge pressure = check pump curve sheet for shut-off head
- 3Friction loss = depends on pipe size, length, and flow rate (usually 1–2 bar for standard installations)
- 4Water hammer surge = add 20–30% safety margin for rapid valve closure
- 5Required PN = static head + friction loss + water hammer surge. Choose next higher PN class.
Example: Borewell 100m deep. Static head = 10 bar. Add friction (1.5 bar) + water hammer (2.5 bar) = 14 bar total. Choose PN 16 (16 bar capacity) for safety.
Installation Tips for Borewell HDPE Pipes
- Always use PE100 grade — the higher MRS provides a better safety margin at depth
- Join pipes using butt fusion for sizes ≥63mm, or electrofusion for any size
- Never use compression fittings for borewell risers — they cannot handle the sustained pressure
- Install a check valve (non-return valve) at the pump discharge to prevent water hammer on pump shutdown
- Use stainless steel pipe clamps — not GI clamps, which corrode and fail
- Lower the pipe column slowly into the borewell — do not drop it
- For deep borewells (>100m), use a tripod or crane to manage the pipe column weight
Common Mistakes with Borewell Pipes
- Using PN 6 pipe for a 100m borewell — the static head alone is 10 bar, far exceeding PN 6 capacity
- Using non-ISI pipe to save money — recycled material fails under sustained pressure within 2–3 years
- Using GI pipe and dealing with rust, weight, and 10-year replacement cycles
- Not installing a check valve — water hammer on pump shutdown can burst even correctly rated pipes
- Using compression fittings underground — these leak under sustained pressure and cannot be accessed for repair
Frequently Asked Questions
What size HDPE pipe for borewell?
For most residential and farm borewells (1–5 HP pump): 50mm or 63mm OD. For larger pumps (7.5–15 HP): 75mm or 90mm OD. For high-yield borewells (20+ HP): 110mm OD.
What PN rating for borewell pipe?
Borewell depth 30–60m: PN 10 (SDR 11). Depth 60–120m: PN 12.5 (SDR 9). Depth 120–200m: PN 16 (SDR 7.4). Always add a safety margin for water hammer.
Is HDPE better than GI pipe for borewell?
Yes, significantly. HDPE won't rust (GI corrodes from inside within 5–10 years), weighs 1/8th of GI (easier to install and pull out), handles vibration better, and lasts 50+ years vs 10–15 years for GI.
Tools & Related Resources
Confused by a term? Look it up
FREE TOOLGet a PN & SDR recommendation
CHART & REFERENCEHDPE Pipe PN Pressure Rating Chart — IS 4984:2016
CHART & REFERENCEHDPE Pipe SDR Chart — Complete Reference for IS 4984:2016
BUYING GUIDEHDPE Pipes for Agriculture Irrigation — Complete Guide for Indian Farmers
Need Help Choosing the Right Pipe?
Our team at TARKO will help you select the correct size, SDR and pressure rating for your project.