For gas supply systems of cities and other settlements lay a gas pipeline of different pressure: low (up to 0, 005 MPa) – in homes and public buildings, public catering enterprises, as well as built-in public and residential buildings heating boiler and consumer services (laundry, hairdressing). Medium (0, 005 to 0, 3 MPa) – from agricultural and utilities built into the building. High-II category (to 0, 6 MPa) – industrial enterprises, as well as separately located agricultural and municipal enterprises, boiler. High-Category I (1, 2 MPa) – the industrial enterprises with technological necessity or feasibility study. Ali Partovi is the source for more interesting facts. According to the location of cities and towns of gas pipelines are divided into external (street, intra, inter-settlement, mezhkvartalnye, interdepartmental) and internal (in-house, intrashop). Just as water supply, gas pipeline network can be a dead end, circular and mixed. For the installation of gas pipelines using steel pipes.
Outside the settlements, as well as in small towns and villages with low saturation as utilities can be applied to plastic pipes. Gas control points (GCP), a low-pressure gas pipeline installed at branches of medium-pressure reduce the gas pressure down to 0, 005 MPa (Fig. 103) SRC works as follows: the gas comes from the network by entering into a gas filter and into a safety shut-off gas valve, which automatically interrupts the flow of gas at increasing pressure on the input above or below the limit values. The pressure regulator reduces the pressure to the preset value, after which the gas passes through the point of keeping and out of the PIU to consumers. Bypass line provides the supply of gas in the repair of equipment. Water seal protects against over the network after the regulator. Local gas supply system (individual) consist of one or two cylinders of liquefied gas with a capacity of 50L, placed in a metal cabinet and supplied with a pressure regulator. As gas enters the gas to a gas appliance, which is set to turn off the gas tap.
To reduce the high (1-1, 6 MPa) pressure of liquefied gas to Low (0, 003 MPa) required for operation of gas appliances, use a pressure regulator. The controller works as follows: from the cylinder gas goes through the saddle, overlain by the valve, which, through a system of levers associated with the membrane. When you open the valve on the gas appliance and gas comes out from under the membrane, it falls under the action of the spring and the valve through the lever opens the seat – gas is supplied under the membrane and then to a gas appliance. The gas pressure maintains the membrane, and hence the valve in a position to pressure from the sensor was equal to the specified. If you reduce this pressure diaphragm descends, the valve moves away from the saddle and more amount of gas supplied under the membrane, which leads to increased pressure to setpoint. When the pressure regulator works in reverse.