Indian Standard Specifications
| # | Type | PVC Pipe |
|---|---|---|
| 1 | IS 4985/1968 | Specification of unplasticised PVC Pipe for Potable Water supplies. |
| 2 | IS 7934/1975 | Code of practices for plastic pipe work for Potable water supplies. |
| 3 | Part I | Choice of materials and general recommendations. | 4 | Part II | Laying and jointing of unplasticized PVC Pipes |
| 5 | IS 7834/1975 | Specification for injection Moulded socket fittings with solvent current joints for water supplies. |
| 6 | Part I | General requirements | 7 | II | Specific requirements for 45” Elbow |
| 8 | III | Specific requirements for 90” Elbow |
| 9 | IV | Specific requirements for 45” Tee |
| 10 | V | Specific requirements for 90” Tee |
| 11 | IV | Specific requirements for Sockets |
| 10 | VII | Specific requirements for Unions |
| 11 | VIII | Specific requirements for Caps |
PVC Pipes have the following properties
It is essential that Rigid PVC Pipe system should be tested for short and long term hydraulic test and other tests as stipulated in the Indian Standards
The following physical characteristics and mechanical properties are ensured.
Visual: - The Pipes shall be reasonably round and internal and external surfaces shall be smooth and clean, fires from growing and other defects. The end shall be clean and square with axis of pipes
Opacity: The Wall of the pipe shall not transmit more the 0.2% of variable light falling on it.
Effect on Water: The pipes shall not leave any detrimental effect on composition of water flowing through them.
| # | Properties | PVC Pipes |
|---|---|---|
| 1 | Specific Gravity | 1.36 -1.43 |
| 2 | Tensile Strength | 45 kgf/cm2 – 56 kgf/cm2 |
| 3 | Elongation | 80 |
| 4 | Mark | @mdo |
| 5 | Modulus of Elasticity | 30000 – 33750 kgf/cm2 |
| 6 | Compressive Strength | 600 – 700 kgf/cm2 |
| 7 | Heat Distortion temp. At 18.5 Kgf/cm | 75’c |
| 8 | Coefficient of linear Expansion | 5.5 x 10 m/m”c |
| 9 | Thermal Conductivity | 4 x 10 call/sec/cm2/c” /cm |
| 10 | Flammability | Self Extinguishing |
| 11 | Impact Strength 0’c | 0.5-1 ft/b/inch of match |
| 12 | Impact Strength 20’c | 1 – 2 ft/b/inch of match |
Mechanical properties
The pipe shall not leave any detrimental effect on composition of water flowing through them.
1. The pipe shall withstand hydraulic pressure equal to one and a half time the maximum working pressure for atleast one hour at room temperature without any sign of leakage/weeping.
2. It shall withstand a circumferential street of 360 kg/cm2 for atleast one hour 27’c without any sing of leakage/weeping.
3. The extrapolated circumferential lowest stress at 50 years shall not be less than 190 kg/cm2
4. When tested a length of pipe approx 20cm long should not alter in length by more than 5% after being immersed in oil, free from aromatic hydrocarbon or ethylene glycol at 150’ +2’C for 15 minutes and then allowed to cool.
5. Each specimen shall be conditioned in a water bath for atleast one hour prior to test at 0’ +1’C an impact testing machine shall be used for the purpose.
Stacking and Transport
The pipes shall normally be supplied in standard length of 5 and 6 meters and shall be indelibly marked at intervals of not more than 3 meters. The marking shall reflect manufacturer’s trademarks, outside diameter, maximum working pressure and I.S.I. Certification work.
Methods of Sampling
- A specimen of the thinnest walled pipe shall be used for opacity test.
- After the machine has been set of pipe shall be taken from each shift one and during each year each size and class of pipes shall be tested.
- For short term hydraulic test, each sample of pipe, the length of which shall be not less than 25 cm or more than 75 cm shall be taken atleast once in every 8 hours and tested. For long term hydraulic test, the specimen shall confirm to that for short term hydraulic test and the testing should be done at least one in a year for all sizes and classes for pipes.
- For impact strength, a specimen shall be a complete section of 300 cm long pipe. Sufficient specimens shall be taken to ensure that atleast one is taken form each shift. If a specimen shows no fractures or cracks thought its complete wall thickness no further specimens needs be taken from the shift.
DIMENSIONS OF UNPLASTICIZED PIPES
| Outside Tolerance | Wall thickness for working pressures (Kgs/Cm2) | |||||||
|---|---|---|---|---|---|---|---|---|
| Diameter on OD | 2.5 Kgs/Cm2 | 4.0 Kgs/Cm2 | 6.0 Kgs/Cm2 | 10.0 Kgs/Cm2 | ||||
| Min | Max | Min | Max | Min | Max | Min | Max | |
| 90 + 0.3 | 1.3 | 1.7 | 2.1 | 2.6 | 3.7 | 3.7 | 5.0 | 5.7 |
| 110 + 0.4 | 1.6 | 2.0 | 2.5 | 3.0 | 3.7 | 4.3 | 6.1 | 7.0 |
| 125 + 0.4 | 1.8 | 2.2 | 2.9 | 3.4 | 4.3 | 5.0 | 6.9 | 7.7 |
| 140 + 0.5 | 2.0 | 2.4 | 3.2 | 3.8 | 4.8 | 5.5 | - | - |
| 160 + 0.5 | 2.3 | 2.8 | 3.7 | 4.3 | 5.4 | 6.2 | - | - |
| 180 + 0.6 | 2.6 | 3.1 | 4.2 | 4.9 | 6.1 | 7.0 | - | - |
| 200 + 0.6 | 2.9 | 3.4 | 4.6 | 5.3 | 6.8 | 7.7 | - | - |
| 225 + 0.7 | 3.3 | 3.9 | 5.2 | 6.0 | 7.6 | 8.6 | - | - |
| 250 + 0.8 | 3.6 | 4.2 | 5.7 | 6.5 | 8.5 | 9.6 | - | - |
| 280 + 0.9 | 4.1 | 4.8 | 6.4 | 7.3 | 9.5 | 10.7 | - | - |
| 315 + 1.0 | 4.6 | 5.3 | 7.2 | 8.2 | 10.7 | 12.0 | - | - |
The wall thickness of pipes are based on a safe working stress of 86 kgf/cm2 at 270 c and working pressures get reduced at higher temperature.
RAW MATERIAL REQUIREMENT AND AVAILABILITY
Manufacture of Rigid PVC Pipes requires the following Raw Materials is specific proportions depending on the desired end Products.
-
PVC Resin
- Stabilisers
- Fillers
- Pigments
- Lubricants
Additives
PVC Resin (POLYVINYL CHLORIDE): Is a polymer of Vinyl Chloride. The PVC molecule consists of a large number of molecules of the monomer Vinyl Chloride which are linked together to form a long chain. This is done by liquefaction of the gaseous Vinyl chloride and making a suspension or emulsion of the liquids in water by adding an emulsifier. Under the influence of suitable Catalysts, the Vinyl chloride molecules are linked together to from long chains. The PVC that is formed is separated from the liquid as a white powder and is called PVC Resin, a thermoplastic substance that is the basic raw material for PVC Pipe processing.
The purpose of the additives is to prevent decomposition of PVC at higher temperatures and to permit softened mass to be shaped into articles like pipe, profiles and other engineering articles, while lubricants help heat absorption in a uniform manner and also smooth passing of the molten extrudate through the die for assuming the desired size and shape. Fillers and added to improve the rigidity of the mass while lowering the cost of production and pigments are used to given the desired colour.