What is BS 3505 – Requirements for unplasticized PVC-U pressure pipes about? 
Unplasticized polyvinyl chloride (PVC-U) are those homopolymers of vinyl chloride which lacks the flexibility due to the absence of plasticizers in it. Given its inherent rigidity and durability, the make for an excellent choice in applications such as pressure piping systems.
BS 3505 is a European Standard that discusses unplasticized PVC-U pressure pipes for cold potable water.
The main aim of BS 3505 is to ensure the PVC-U pressure pipes are fit for purpose such that the integrity of the overall water supply system is maintained.
BS 3505 specifies requirements for unplasticized PVC-U pipes up to and including nominal size 24, for conveying cold potable water at pressures up to and including 9, 12 or 15 bar1) at 20 °C, depending on the size.
Who is BS 3505 - Requirements for unplasticized PVC-U pressure pipes for?  
BS 3505 on unplasticized PVC-U pressure pipes is relevant to: 
- Manufacturers of PVC-U pipes
- Anyone involved in designing, operation, installation and maintenance of water supply systems using PVC-U pressure pipes
- Building architects
- Product designers and specifiers
- Quality control and testing personnel 
- Local bodies
- Regulatory authorities
Why should you use BS 3505 - Requirements for unplasticized PVC-U pressure pipes? 
BS 3505 classifies PVC-U pressure pipes based on their pressure tolerances.
BS 3505 walks you through specific requirements for the materials, dimensions and tolerances, and physical properties for optimal performance of the unplasticized PVC-U pressure pipes.
Apart from that, BS 3505 also provides:
- Method for the analysis of results from the determination of the long-term hydrostatic strength of pipe
- Method for the determination of impact resistance
- Method for the determination of fracture toughness
- Guidance on calculation of fracture toughness
By undertaking these tests, you can demonstrate the quality, performance and reliability of PVC-U pressure pipes, that can be particularly useful for quality control purposes.
Thus, if you are a manufacturer of unplasticized PVC-U pressure pipes used for cold portable water, compliance with BS 3505 guidelines can help you to ensure that your products meet the performance requirements of the water supply system. As a result, you can avoid product failures arising from deformation, leakages, and cracks that could compromise the operational integrity of the overall water supply system.
