plumber Islington Safety and drain issue
In some systems the drain is for discharge of waste fluids, such as the drain in a sink in which the water is drained when it is no longer needed.
In the United Kingdom, plumbers refer to waste water as 'bad water'. This is under the premise that the water they are moving from one area to another via the use of a drain is not needed and can be removed from the area, like a 'bad apple' being removed from a fruit bowl.
In other systems, such as fountains or swimming pools where waste fluid is recirculated, the drain is the input to the recirculating pumping machine.
In the last case, there is an obvious safety issue, because many people do not expect to encounter more than the head of water above the drain when touching a drain. For example, in a recent case, a lifeguard went to the bottom of a pool to retrieve something and his hand got stuck because of the extra pressure from the pump. When there is a recirculating pump, the risk of suction consists of the head of water, plus the suction of the pump (up to a maximum of 1 atmosphere).
Źródło: https://en.wikipedia.org/wiki/Drain_(plumbing)
Standards of plastic pipes
Plastic pipe systems fulfill a variety of service requirements. Product standards for plastics pipe systems are prepared within the CEN/TC155 standards committee. These requirements are described in a 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 capable of fulfilling the specific requirement for each application. They do so over a long lifetime and with reliability and safety.citation needed The key success factor is achieved by maintaining consistently high quality levels. For plastic pipe products, these levels are defined by the different standards. Two aspects are fundamentally important for the performance of plastic pipes: flexibility and long lifetime.2
Źródło: https://en.wikipedia.org/wiki/Plastic_pipework
Worth to know
Plumbing is any system that conveys fluids for a wide range of applications. Heating and cooling, waste removal, and potable water delivery are among the most common uses for plumbing however plumbing's not limited to these applications.1 Plumbing utilizes pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids.2 Trades that work with plumbing such as boilermakers, plumbers, and pipefitters are referred to the plumbing trade. In the Developed world plumbing infrastructure is critical for public health and sanitation.
The word derives from the Latin plumbum for lead, as the first effective pipes used in Roman era were lead pipes
Źródło: https://en.wikipedia.org/wiki/Plumbing