- 1. Introduction
- SpecX quick selector
- 2. Primary classification
- 3. Codes and standards
- 4. Components of plumbing systems
- 5. Pipe materials and applications
- 6. Fixture units and pipe sizing
- 7. Water storage and pumping systems
- 8. QA/QC and site checklist
- 9. Common failures and remedials
- 10. Testing and commissioning
- 11. Typical BOQ items
- 12. Recommended tests
- 13. SpecX Key Takeaways
- 14. Additional Data : Master Comparison Matrix
- 15. Application Suitability Matrix
1. Introduction
Plumbing systems are essential for the distribution of potable water, disposal of wastewater, and maintenance of sanitary conditions in buildings. They comprise internal water supply, soil and waste systems, and external drainage networks.
A well‑designed plumbing system ensures hygienic wastewater disposal, reliable water supply under sufficient pressure, leak‑free operation and corrosion resistance, easy maintenance, and long service life.
SpecX quick selector
- Supply: CPVC (hot/cold, SDR 11/13.5) for concealed lines; PPR PN 20–25 for high‑rise risers; HDPE PN 10–16 for external mains
- Drainage: UPVC SWR (IS 13592) with 1:40 minimum slope for soil/waste; provide vent stacks and cleanouts at changes in direction
- Storage and pumps: UG tank sized for 1‑day demand, OH tank ~ one‑third day; transfer and booster pumps with NRVs and level controls
- Testing: Hydrostatic 1.5 × working pressure before concealment; smoke test on stacks; chlorination before handover
2. Primary classification
Category | Description | Typical Components |
Water supply systems | Carry potable and non‑potable water | Overhead tanks, down‑takes, risers, pipes, valves |
Soil and waste systems | Remove wastewater and sewage | Soil pipes, waste pipes, traps, vent pipes |
Rainwater / storm drainage | Collect and discharge rainwater | Gutters, downpipes, rainwater drains |
External networks | Connect building to municipal services | Inspection chambers, manholes, gully traps |
3. Codes and standards
Standard | Description |
IS 1172:2020 | Water supply, drainage, and sanitation for buildings |
IS 2065 | Water supply in buildings (installation code) |
IS 5329 | Sanitary pipework and fittings |
IS 1742 | Building drainage layout and design |
NBC 2016 (Part 9) | Plumbing, sanitation, solid waste management |
IS 2470 (Part 1 & 2) | Septic tanks and soak pit design |
UPC‑I / CPHEEO Manual | Plumbing and public health guidelines |
4. Components of plumbing systems
Sub‑system | Key elements | Material options | Relevant IS codes |
Water supply | Storage tanks, risers, down‑take, branch piping, valves | GI, CPVC, PPR, UPVC, HDPE | IS 1239, IS 4985, IS 15778 |
Soil and waste | Traps, soil stack, vent pipe, waste pipe, inspection chamber | UPVC, SWR, HDPE | IS 13592, IS 4985 |
Rainwater | Gutters, downpipes, floor traps | PVC, cast iron | IS 4985, IS 1729 |
Fixtures and fittings | Faucets, showers, WCs, washbasins | Brass chrome plated, stainless steel | IS 2556 |
Valves | Ball, gate, check, float valves | Brass, bronze, PVC | IS 778 |
Pumps and accessories | Transfer pumps, pressure booster, float switches | Cast iron / stainless steel | IS 9079 |
Sanitary equipment | Septic tank, grease trap, inspection chambers | RCC, FRP, brick masonry | IS 2470, IS 4111 |
5. Pipe materials and applications
Pipe material | Type | Pressure rating | Common use | Life expectancy |
UPVC | Non‑pressure | SWR drainage | Soil, waste, rainwater | 25–30 yrs |
CPVC | Hot and cold water | 10–15 bar | Internal water supply | 40–50 yrs |
HDPE | Pressure / non‑pressure | 6–16 bar | External networks | 50+ yrs |
GI (galvanized iron) | Heavy / medium class | 10–12 bar | Older domestic systems | 15–20 yrs |
PPR | Hot/cold supply | 10–16 bar | High‑rise supply systems | 40 yrs |
Cast iron (CI) | Socket and spigot | Gravity flow | Underground drainage | 50+ yrs |
6. Fixture units and pipe sizing
- Fixture Unit (FU) is the load factor assigned to each plumbing fixture (e.g., WC = 6 FU, basin = 1 FU). Total FU in a system determines the pipe diameter.
- Typical internal supply pressure: 2–3 kg/cm². Minimum flow velocity: 0.6 m/s (supply), 0.9 m/s (waste).
7. Water storage and pumping systems
Component | Standard | Typical practice |
UG tank | IS 3370 | Designed for 1‑day capacity |
OH tank | IS 3370 | ~ one‑third of daily requirement |
Pumping system | IS 9079 | Level controls and NRVs |
Booster system | IS 11346 | For high‑rise buildings |
Water meter | ISO 4064 | To measure consumption |
8. QA/QC and site checklist
Stage | Checkpoint | Acceptance criteria |
Pre‑installation | Material inspection | IS certification and MTC check |
Laying | Slope in drainage | 1:40 (min) for soil and waste |
Pressure testing | Hydrostatic test | 1.5 × working pressure |
Joints | Solvent weld / threaded | No visible leak |
Pump testing | Pressure and flow | Matches design head |
Final inspection | Functional test | No leaks or noise |
9. Common failures and remedials
- Leakage at joints → poor solvent welding; re‑weld with correct adhesive and prep
- Low pressure → air lock or undersized pipe; add air vents or upsize lines
- Backflow in drainage → inadequate slope; regrade, ensure trap seals and venting
- Water hammer/noise → fast closing valves/loose supports; add arrestors, fix supports
- Pump short‑cycling → faulty pressure switch; replace or recalibrate, check bladder tanks
10. Testing and commissioning
- Hydrostatic test: 1.5 × design pressure for 1 hour
- Smoke test: check drainage leaks
- Flow test: ensure discharge per FU design
- Pump test: verify head and flow rate per IS 9079
11. Typical BOQ items
Item No. | Description | Unit | Remarks |
1 | CPVC piping, SDR 11, hot and cold water supply | m | With fittings and clamps |
2 | UPVC SWR pipe, Class B, IS 13592 | m | Including joints and supports |
3 | CI manhole with cover | Nos | 600 × 600 mm, IS 1726 |
4 | GI fittings and valves | Nos | As per IS 1239 |
5 | Water storage tanks | L | ISI marked, installed complete |
12. Recommended tests
Test | Purpose | Frequency |
Hydrostatic pressure test | Leak test for supply pipes | Every line before concealment |
Smoke test | Check drainage tightness | Every floor stack |
Water flow test | Ensure discharge rate | Final testing |
Chlorination test | Disinfection of system | Before handover |
13. SpecX Key Takeaways
A. UPVC → Default choice for cold & SWR systems (low cost, plumber friendly)
B. CPVC → For hot water & concealed systems (ideal balance of cost & performance)
C. PPR → For premium or high-pressure plumbing (fusion-welded, long life)
D. HDPE → For underground & industrial use (flexible, high durability)
14. Additional Data : Master Comparison Matrix
Parameter | UPVC | CPVC | PPR | HDPE |
Full Form | Unplasticized Polyvinyl Chloride | Chlorinated Polyvinyl Chloride | Polypropylene Random Copolymer | High-Density Polyethylene |
Type of Material | Rigid Thermoplastic | Modified Thermoplastic | Thermoplastic (Rigid) | Flexible Thermoplastic |
Temperature Resistance | Up to 45°C | Up to 93°C | Up to 95°C | Up to 60°C |
Pressure Rating (PN) | PN 6–12.5 | PN 10–25 | PN 10–25 | PN 6–16 |
Thermal Expansion | Moderate | Low | Low | High |
Chemical Resistance | Excellent | Excellent | Excellent | Excellent |
UV Resistance | Moderate | Good (better than UPVC) | Fair | Excellent |
Flexibility | Low | Medium | Medium | Very High |
Jointing Method | Solvent cement (cold welding) | Solvent cement | Heat fusion | Butt fusion / Electrofusion |
Joint Strength | Moderate | Good | Excellent (homogeneous) | Excellent (monolithic) |
Leakage Risk | Medium (depends on workmanship) | Low | Very Low | Very Low |
Cost Range (₹/m) | ₹60–120 | ₹100–180 | ₹120–200 | ₹100–150 |
Maintenance Requirement | Low | Very Low | Very Low | Very Low |
Installation Skill | Easy (plumber-friendly) | Easy | Moderate (requires trained welder) | High (fusion technician) |
ISI Standard | IS 4985 / IS 13592 (SWR) | IS 15778:2007 | IS 15801:2008 | IS 4984:2016 |
Color | White / Grey | Cream / Off-white | Green / Blue | Black with blue stripe |
Service Life | 30–40 years | 40–50 years | 50+ years | 50+ years |
Internal Surface Finish | Smooth | Smooth | Smooth | Smooth |
Suitability for Concealed Use | Limited | Excellent | Excellent | Limited |
Fire Resistance | Self-extinguishing | Self-extinguishing | Fair | Fair |
Noise Reduction | Average | Good | Excellent | Good |
Environment Impact | Moderate | Moderate | Low | Low |
Repairability | Easy (cut & join) | Easy | Medium | Difficult |
Recyclability | Yes | Yes | Yes | Yes |
Aesthetic Appeal (Visible Lines) | Fair | Good | Excellent | Poor (industrial look) |
15. Application Suitability Matrix
Application | UPVC | CPVC | PPR | HDPE |
Cold Water Supply | ✅ Excellent | ✅ Good | ✅ Good | ✅ Good |
Hot Water Supply | ❌ Not Suitable | ✅ Excellent | ✅ Excellent | ⚠️ Limited |
SWR (Soil, Waste, Rainwater) | ✅ Excellent | ⚠️ Limited | ⚠️ Limited | ✅ Excellent (large drains) |
Underground Supply | ⚠️ Limited | ⚠️ Limited | ⚠️ Limited | ✅ Excellent |
High-Rise Pressure Lines | ⚠️ Limited | ✅ Good | ✅ Excellent | ✅ Good |
Industrial / Chemical Lines | ✅ Excellent | ✅ Excellent | ⚠️ Limited | ✅ Excellent |
Firefighting (Non-metallic) | ⚠️ Limited | ⚠️ Limited | ⚠️ Limited | ✅ Good |
UV-Exposed Installations | ⚠️ Moderate | ✅ Good | ⚠️ Moderate | ✅ Excellent |
Concealed Plumbing | ⚠️ Limited | ✅ Excellent | ✅ Excellent | ❌ Not Preferred |
Domestic (Residential) | ✅ Excellent | ✅ Excellent | ✅ Premium | ✅ External Lines Only |