Systems of gas supply represent a difficult complex of. A number of factors has impact on a choice of system of gas supply of the city. It first of all: the size of the gasifiable territory, feature of its planning, population density, number and a of consumers of gas, existence of natural and artificial for laying of gas pipelines (the rivers, dams, ravines, ways, underground constructions, etc.). At design of system of gas supply develop a number of options and make their technical and economic comparison. Apply option to construction.
For ventilation of GRP on a roof the deflector providing triple air exchange in the main room of GRP is installed. The entrance door to the main room of GRP in the lower its part has to have cracks for air pass.
Shutoff valves (latches, gates, pith cranes), are applied in GRP and GRU it has to be calculated on the gas environment. The main criteria at a choice of shutoff valves are the nominal diameter of DU and executive pressure of RU.
In most cases for the cities with the population to 500 thousand people of the most economically expedient the two-level system is. For big cities with the population more than 1000000 people and existence large industrial enterprise preferable are three or multistage systems.