Water supply system is a utility system intended to deliver fresh (drinking and process) water from water abstraction intakes to the end user.
The core of a water supply system consists of pipes (main) interconnected with special elements called fittings. The pipelines inside a building are indoor, while those outside, outdoor, the latter being generally buried underground for protection against impact, weather or freezing.
Outdoor water supply pipelines by application:
· Domestic pipelines intended to supply potable water to residential, public and industrial buildings
· Industrial pipelines intended to supply water to industrial sites to enable their performance
· Fire water lines used to prevent or suppress fire in case of emergency
· Irrigation water distribution systems used in agriculture to water plants and to maintain the required soil moisture level.
Individual homesteads and small enterprises can use the same water supply system for various applications.
Water pipes by material:
1. Metal pipes which can be:
· Steel (galvanised or non-galvanised) — low-cost, rigid and durable, but heavyweight and low-resistant to corrosion; threaded or fused connections
· Copper — corrosion resistant, strong, durable, non-sensitive to temperature fluctuations, bur comparatively expensive and easily bendable; connection by a blowtorch only
· Cast iron — strong, corrosion resistant, non-sensitive to temperature fluctuations, with low expansion factor, but extremely heavy and easily go clogged because of rough inner surface; connection by means of seals and sockets
2. Plastic pipes which are lightweight, cheap and easy-to-install. Disadvantages include high thermal expansion factor and low UV resistance.
Plastic tubes can be made of various polymers with different properties:
· Polybutylene (PB) — elastic material with high thermal conductivity. Working temperature – max. +90 °C
· Polyethylene (PE) — cheap, elastic and strong material with high resistance to low temperatures and lowresistance to high temperatures. Can be used for cold water distribution in individual homes
· Cross-lines polyethylene (PEX) is a high-performance low-thermal-conductivity material resistant to both high and low temperature, durable and noise-proof, capable of reducing depositions on the pipe inner surface, easy- and quick-to-install, but more expensive than PE
· Polyvinyl chloride (PVC) is the least plastic material, though with high UV resistance and fire safety. Disadvantage: eco-unfriendly production process involving chlorine
· Polypropylene (PP) — user-friendly and cheap material resistant to both high and low temperatures. PP pipes are easy-to-install, durable, affordable and, therefore, very popular
3. Plastic-metal composite pipes combine elements and properties of plastic and metal items. These consist of three layers: polymer inner and outer ones, and metal, usually aluminium, interlayer.
Besides, water pipes can differ by diameter (ID, OD, inlet, outlet) and pressure rating.
The best pipe option in each case shall be appropriate to the environment and compliant to the applicable local/regional/national regulations.