IS 4985:1994 is the Indian Standard (BIS) for unplasticized pvc pipes for potable water supplies - specification. This standard specifies the requirements for unplasticized PVC (uPVC) pipes intended for potable water supplies. It covers material composition, dimensions, pressure classifications, performance criteria such as impact strength and pressure resistance, and mandatory marking for pipes.
Specifies requirements for unplasticized PVC pipes suitable for carrying potable water, relevant for pool piping.
Quick Reference — IS 4985:1994 uPVC Pipes (legacy)
Unplasticised PVC pipes for potable water supply — older edition. Pressure classes, dimensions, jointing.
| Reference | Value | Clause |
|---|
| Pressure class — Class 1 | 0.25 MPa working pressure | Cl. 4 (Table 1) |
| Pressure class — Class 2 | 0.4 MPa working pressure | Cl. 4 (Table 1) |
| Pressure class — Class 3 | 0.6 MPa | Cl. 4 (Table 1) |
| Pressure class — Class 4 | 1.0 MPa | Cl. 4 (Table 1) |
| Pressure class — Class 5 | 1.25 MPa | Cl. 4 (Table 1) |
| Pressure class — Class 6 | 1.6 MPa | Cl. 4 (Table 1) |
| Material — uPVC | vinyl chloride homopolymer | Cl. 5.1 |
| Density of pipe | 1380–1460 kg/m³ | Cl. 5.2 |
| Outside diameter — typical sizes | 20, 25, 32, 40, 50, 63, 75, 90, 110 mm | Cl. 6 (Table 2) |
| Outside diameter — large | 125, 140, 160, 180, 200, 225, 250, 315, 400 mm | Cl. 6 (Table 2) |
| Maximum working temperature | 45 °C | Cl. 4.2 |
| Vicat softening temperature | ≥ 79 °C | Cl. 8.2 (Table 4) |
| Tensile strength — minimum | 45 N/mm² | Cl. 8.3 (Table 4) |
| Hydraulic test pressure — Class 4 | 2.5 × working = 2.5 MPa for 1 hour | Cl. 9.1 |
| Tolerance on outside diameter (≤ 50 mm) | +0.3 mm, −0 | Cl. 6.2 (Table 3) |
| Tolerance on outside diameter (110 mm) | +0.4 mm, −0 | Cl. 6.2 (Table 3) |
| Wall thickness — example OD 110, Class 4 | 5.3 mm | Cl. 6 (Table 2) |
| Joint type — solvent cement | for ≤ 110 mm typical | Cl. 7.2 |
| Joint type — rubber ring (RR) | for ≥ 75 mm pressure pipe | Cl. 7.3 |
| Marking — pipe surface | manufacturer + IS 4985 + size + class | Cl. 11 |
⚠ Superseded by IS 4985:2021. The 1994 edition is still referenced on legacy pipeline drawings and in older GSC searches. Major pressure-class system reorganised in 2021.
Overview
- Status
- Current
- Usage level
- Essential
- Domain
- Water Resources — Swimming Pools and Sports Facilities
- Type
- Specification
- Amendments
- Amendment 1 (November 2001); Amendment 2 (May 2002); Amendment 3 (October 2002); Amendment 4 (July 2004)
Also on InfraLens for IS 4985
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
Practical Notes
! Pipe pressure rating (e.g., 6 kgf/cm²) is for water at 27°C and must be derated for higher operating temperatures.
! Pipes are designated by their nominal outside diameter (OD). Ensure compatibility with fittings which are typically socketed.
! Proper jointing using solvent cement (as per IS 14182) is critical to prevent leaks. Both pipe end and fitting socket must be cleaned and primed before applying cement.
Frequently referenced clauses
Updates & Amendments4 amendments
Amendment 1 (November 2001)
Amendment 2 (May 2002)
Amendment 3 (October 2002)
Amendment 4 (July 2004)
Consolidated list per BIS. For the text of each amendment, refer to the BIS portal link above.
uPVCplasticpipesunplasticized polyvinyl chloride
International Equivalents
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International Comparison — Coming Soon
We're adding equivalent international standards for this code.
Key Values6
Quick Reference Values
Working Pressure Classes2.5, 4, 6, 8, 10, and 12.5 kgf/cm²
Standard Test Temperature27 ± 2 °C
Opacity RequirementShall not transmit more than 0.2% of visible light
Max Longitudinal Reversion5 percent at 150 °C
Minimum Vicat Softening Temperature80 °C
Minimum Wall Thickness for 110mm OD, Class 6 pipe4.2 mm
Tables & Referenced Sections
Key Tables
Table 1 - Dimensions of Unplasticized PVC Pipes
Table 2 - Requirements for Unplasticized PVC Pipes for Potable Water Supplies
Table 3 - Impact Strength at 27°C
Key Clauses
Clause 4 - Material
Clause 5 - Dimensions of Pipes
Clause 6 - Classification and Pressure Rating
Clause 8 - Performance Requirements
Clause 10 - Marking
Frequently Asked Questions4
What are the standard pressure classes for IS 4985 pipes?+
2.5, 4, 6, 8, 10, and 12.5 kgf/cm² (or bar), which represent the working pressure at 27°C (Clause 6.1).
Can these pipes be used for hot water?+
No, this standard is for cold potable water services only. uPVC loses strength and stiffness rapidly at elevated temperatures.
What does the 'OD' of a pipe mean?+
OD stands for Outside Diameter. IS 4985 pipes are specified by their nominal outside diameter, e.g., 110 mm OD (Clause 5).
What is the purpose of the reversion test?+
The longitudinal reversion test (Clause 8.4) checks for induced stresses from the manufacturing process. A high reversion value (over 5%) indicates poor processing and can lead to long-term performance issues.
QA/QC Inspection Templates
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QA/QC templates coming soon for this code.