Water supply pipes

The diameter is selected by the design flow rate and the acceptable flow velocity. The higher the flow, the larger the diameter needed: a service line to a private house is usually d32–d63, intra-block and street networks use d110–d225, and mains and water conduits use d315 and above. Undersizing is costly — head loss and pump load grow; oversizing means overpaying for material and installation.

Pipe-Plast makes the full size range from 20 to 1200 mm, so you can match a pipe to a specific section without switching suppliers. Common water-supply diameters are 63, 110, 160, 200, 225 and 315 mm. If you are unsure, our manager will calculate the diameter and SDR for your design pressure and flow.

SDR (Standard Dimension Ratio) is the ratio of the pipe's outer diameter to its wall thickness. The lower the SDR, the thicker the wall and the higher the working pressure the pipe withstands. For PE100 water supply the most common classes are SDR17 (10 atm working pressure), SDR13.6 (12.5 atm) and SDR11 (16 atm).

The class depends on the network pressure: thinner SDR21–SDR26 suit gravity and low-pressure lines, while SDR17 and SDR11 suit pressurised urban networks. The same diameter is produced in several SDR classes, so specify not only the diameter but also the required pressure — then the selection will be precise.

PE100 is the modern standard for pressure pipelines. At the same pressure it allows a thinner wall than PE80: the pipe is lighter, cheaper to transport and install, and offers higher throughput. That is why PE100 is chosen for trunk and urban networks today.

All Pipe-Plast pressure pipes are made of PE100. For higher resistance to cracks and impact, PE100-RC is used — in particular, as the outer layer of a co-extruded pipe. PE80 mainly remains for low-pressure small-diameter tasks and is gradually being replaced by PE100.

The main method is butt fusion welding: the pipe ends are melted with a heating plate and pressed together, forming a monolithic joint stronger than the pipe itself. Butt welding is used for diameters of 63 mm and above. For chambers, tie-ins and complex assemblies, electrofusion welding is used — a fitting with a built-in heater.

Small-diameter pipes (up to 63 mm) are conveniently joined with compression fittings without welding equipment. Small diameters are supplied in coils of 50–200 m, which reduces the number of joints; large ones come in 12 m lengths. Pipe-Plast helps select the joining method and welding equipment for the scope of work.