They work full-time in a variety of plants, hydraulic or sign contracts-orders for certain services.Some plumbers also run his own business, under which perform minor plumbing services.
Plumbing equipment includes devices often hidden behind walls or in utility spaces which are not seen by the general public.
It includes water meters, pumps, expansion tanks, backflow preventers, water filters, UV sterilization lights, water softeners, water heaters, heat exchangers, gauges, and control systems. Specialized plumbing tools include pipe wrenches, flaring pliers, pipe vise, pipe bending machine, pipe cutter, dies and joining tools such as soldering torches and crimp tools.New tools have been developed to help plumbers fix problems more efficiently.
Gaskets are mechanical seals, usually formed like a ring and used for sealing of flange joints.
They are available with an inner ring and outer ring, which is also known as the cantering ring.Ring Joint Gaskets are used with Ring Type Joint (RTJ) flanges.
They are available in octagonal or oval cross sections. A very high surface stress is developed between an RTJ gasket and the flange groove when RTJ is bolted up in a flange.This leads to plastic deformation of the gasket. Thus, the hardness of the gasket is kept less than the hardness of the groove to achieve coining i.e. bringing two metal surfaces of different hardness so tightly together that the softer surface deforms to match harder surface exactly in shape and finish. Źródło: https://en.wikipedia.org/wiki/Piping_and_plumbing_fitting.