Gas is used for heating, power generation, transport, household and many other areas. To ensure its safe and uninterrupted transportation to consumer devices, gas fittings are used.
Purpose and types of gas devices and fittings
Gas fittings and equipment are designed for use on pipelines of transportation and supply systems, as well as distribution of blue fuel. With the help of these devices and mechanisms, the supply is switched on and off, the amount, direction or pressure of the gas flow is changed. Mostly all fittings are characterized by the following main parameters:
· nominal (conditional) pressure;
· nominal diameter (nominal bore).
The first one characteristic is understood as the maximum pressure at a temperature of 20 ° C, which ensures long-term service of various connections of fittings (equipment) and the pipeline. The nominal size (DN or DN) is understood as a characteristic used in pipeline systems, networks as a parameter of the parts to be connected. The fitting of gas system should be done by plumber gas fitters. If you are expert and want to publish your skills, then get the online gas fitter course
Purposes of Gas Fittings
Fittings for gas systems are divided into the following types according to their purpose,
· Shut-off valves – for periodic shutdowns of equipment and instruments, as well as individual sections of the gas pipeline from its other parts. In this capacity, valves, taps and latches are used.
· Regulating – to change and maintain pressure within the specified limits. It includes dampers, gate valves and the like.
· Safety – used to prevent the gas pressure from rising above the permissible value. This is a relief safety valve.
· Shut-off and emergency – for quick automatic shutdown of various gas appliances, devices, as well as pipelines, where the specified mode of their operation is violated. For example, a safety shut-off valve.
· Reverse acting – prevents the gas flow from moving in the opposite direction.
· Condensate drain – automatically removes condensate accumulating in condensate traps and low points of pipelines.
Material of Fittings
Fittings are produced from various materials. According to what the body is made of, it is designated as follows:
· of steel:
carbonaceous – with;
stainless – nzh;
alloyed – HP;
· cast iron:
gray – h;
malleable – kch;
· bronze, brass – B;
· plastics (with the exception of vinyl plastic) – p;
· vinyl last – vp.
Methods for Connecting Gas Devices and Fittings
There are the following connection methods:
· With flanges – used for fittings with a nominal bore of more than 50 mm. Connection to a tank or pipeline is made using flanges. The main advantage is the possibility of multiple installation and dismantling, as well as great strength, reliability and applicability for a very wide range of passages and pressures. Disadvantages: large weight and dimensions, over time, the possibility of loosening the tightening with a subsequent loss of tightness is not excluded.
Flanged – Used for connections with a nominal value of more than 50 mm. The connection of the tank or pipe is done through a flange. The main advantages are high installation and disassembly capability as well as high strength, reliability and application in a wide range of passages and pressures. Disadvantages: High weight and size, over time, the possibility of repairing it with the next damage after closing does not disappear.
· Coupling connection – for equipment with a passage of 65 mm or less. The connection is carried out using couplings with an internal thread, using a hex wrench.
· Tsapkovoe with external thread. An apparatus (for example, a faucet) is screwed directly into the body of another instrument or device by means of a thread.
· Rarely used by welding, non-separable type of connection. Advantages – reliable and complete tightness, minimum maintenance. The disadvantages include the increased complexity of replacement and installation of fittings.
