How to adjust the gas pointer in the yellow area

The gas pointer in the yellow area immediately tightens the rubber cover of the pressure reducing valve until the air pressure comes up. The pressure relief valve cover is not tightened, there is air leakage, and the air pressure can't come up. The pointer must point to the yellow area. Gas is a kind of gas fuel composed of many combustible components. There are many kinds of gases and their compositions are very complicated. Generally, it can be divided into natural gas and artificial gas.

Gas:

Coal gas is a combustible gas processed from coal. According to the processing method, gas properties and uses, it can be divided into: water gas, semi-water gas and air gas (or producer gas) obtained from coal gasification. These gases have low calorific value, so they are collectively called low calorific value gases; The gas obtained by dry distillation and coking of coal is called coke oven gas. It belongs to medium calorific value gas and can be used as urban civil fuel. Carbon monoxide and hydrogen in coal gas are important chemical raw materials.