Do You need a plumber?
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.Źródło: https://en.wikipedia.org/wiki/Plumbing
The importance of the valvesplumbers HillingdonValves are found in virtually every industrial process, including water and sewage processing, mining, power generation, processing of oil, gas and petroleum, food manufacturing, chemical and plastic manufacturing and many other fields. People in developed nations use valves in their daily lives, including plumbing valves, such as taps for tap water, gas control valves on cookers, small valves fitted to washing machines and dishwashers, safety devices fitted to hot water systems, and poppet valves in car engines. In nature there are valves, for example one-way valves in veins controlling the blood circulation, and heart valves controlling the flow of blood in the chambers of the heart and maintaining the correct pumping action. Valves may be operated manually, either by a handle, lever, pedal or wheel.
Valves may also be automatic, driven by changes in pressure, temperature, or flow.
These changes may act upon a diaphragm or a piston which in turn activates the valve, examples of this type of valve found commonly are safety valves fitted to hot water systems or boilers. More complex control systems using valves requiring automatic control based on an external input (i.e., regulating flow through a pipe to a changing set point) require an actuator.Źródło: https://en.wikipedia.org/wiki/Valve
All such work can be carried out also by plumbers self-employed.
You just have to reckon with the fact that the services contract with an independent plumber probably will prolong the work carried out.However, this should not affect their quality, and sometimes it turns out that the plumber running his own business applies doubly to perform the outsourced tasks themselves.