Plumbing - usage of steel pipes
Galvanized steel potable water supply and distribution pipes are commonly found with nominal pipe sizes from 3?8 inch (9.5 mm) to 2 inches (51 mm). It is rarely used today for new construction residential plumbing. Steel pipe has National Pipe Thread (NPT) standard tapered male threads, which connect with female tapered threads on elbows, tees, couplers, valves, and other fittings. Galvanized steel (often known simply as "galv" or "iron" in the plumbing trade) is relatively expensive, and difficult to work with due to weight and requirement of a pipe threader. It remains in common use for repair of existing "galv" systems and to satisfy building code non-combustibility requirements typically found in hotels, apartment buildings and other commercial applications. It is also extremely durable and resistant to mechanical abuse. Black lacquered steel pipe is the most widely used pipe material for fire sprinklers and natural gas.
Źródło: https://en.wikipedia.org/wiki/Plumbing
Repair plumbing services performed in the houses
To common plumbing services should be installation of new sanitary facilities and repair of these devices and mending other hydraulic faults. Frequently performed hydraulic services for apartments are repairing a leaky faucet or washing machines, which ceased to spin the laundry. Similar repairs are done at home. But in such buildings often you have to also carry out work related to repair leaks resulting in the installation of plumbing. This is because the state of the responsibility of owners of housing blocks and homes can have installations mounted a dozen years earlier. Similar situation may occur also in the case of hospitals.
About plastic pipes
Plastic pipework is used for the conveyance of drinking water, waste water, chemicals, heating fluid and cooling fluids, foodstuffs, ultra-pure liquids, slurries, gases, compressed air and vacuum system applications.
Plastic pipe systems fulfil a wide variety of service requirements. Product standards for plastics pipe systems are prepared within the standards committee known as CEN/TC155. These requirements are precisely described in a complete set of European Product Standards for each application alongside their specific characteristics.
For example:
Conveyance of drinking water: Hygienic requirements
Conveyance of gas: Highest Safety requirements
Plastic pipes for radiant heating and floor heating: Temperature resistance over decades
Sewer applications: High chemical resistance.
Plastic pipes are perfectly capable of fulfilling the specific requirement for each application. They do so with a high level of performance over a long lifetime and with reliability and safety.
The key factor for success is achieved by maintaining consistently high quality levels. For plastic pipe products, these levels are closely defined by the different standards.
Źródło: https://en.wikipedia.org/wiki/Plastic_pipework