For a long time, many users have a habit, is by looking at the cylinder pressure reducing valve on the pressure gauge, to determine how much this bottle of gas, however, don't know if you have to note that this table is "pressure gauge", not "gas scale", it is not directly reflect the gas bottle, also does not have a "gas scale" can directly reflect the air inside the bottle, then, What is the relationship between this "pressure" and liquefied gas?
01, pressure gauge on the pressure reducing valve
This pressure gauge, in fact, reflects the pressure of liquefied gas in the cylinder, the function is used to measure and display the pressure of liquefied gas in the cylinder.
The pressure gauge on the cylinder pressure reducing valve does not fully reflect the amount of air filled in the cylinder, because the liquefied gas exists in liquid state and is constantly vaporized in the cylinder, and the pressure can not be seen by the method of oxygen and nitrogen cylinder.
02, pressure gauge quality does not pass the hidden danger
The pressure GAUGE SHOWS the pressure of liquefied GAS in the cylinder and CAN also be used to detect leaks in the connection between the cylinder and the fuel. With table type pressure reducing valve is usually manufacturers in order to meet the needs of consumers, but with table type pressure reducing valve to leak more a chance, if the quality of the pressure gauge is not good, especially the pressure shrapnel quality is poor, the use of this pressure reducing valve is not only unsafe, more like an uncertain bomb, always threatening our lives. And the pressure gauge is set before the pressure regulation, the pressure is relatively high, the safety risk is greater. If the quality of the pressure reducing valve is not passed, the safety of the pressure gauge is greater.
In the past two years, there have been a number of gas accidents in which poor quality pressure reducing valves have been used to flush the pressure gauges and cause fires. Therefore, when choosing a pressure reducing valve, we should choose the pressure reducing valve from the regular manufacturer, and do not use the inferior pressure reducing valve, so as not to cause gas leakage accident. If not, try to use a pressure reducing valve without pressure gauge.
03，Saturated vapor pressure
After the LPG is well charged, if the surrounding conditions are unchanged, this pressure is stable, and the pressure when stable is called "saturated vapor pressure".
Saturated vapor pressure: The pressure of the vapor in equilibrium between the liquid and the gas of a substance under closed conditions at a certain temperature is called saturated vapor pressure.
Put the water in the cup, will continue to evaporate, but if put in airtight glass, the water and the air of the smoke rising pressure in the water evaporation can make the cup, when a certain temperature, the pressure will eventually be stable in a fixed value, the liquid water to evaporation, water vapor also continuously condense into liquid water, and the speed of the two are equal, At this point, liquid water does not decrease, nor does water vapor increase, and a steady state is reached.
Like density, melting point and boiling point, saturated vapor pressure is a physical property of matter that changes with temperature. The pressure gauge of the cylinder pressure reducing valve reflects the saturated vapor pressure of the liquefied gas in the cylinder. This saturated vapor pressure is a physical property of the liquefied gas itself, which changes with the surrounding temperature.
Relief valve on the pressure gauge is an auxiliary tool, the factory does not need to do identification like measuring instruments, so the measurement accuracy is uneven, and the relief valve pressure gauge also have no a unified standard, some did not indicate the unit of measurement, only a few interval, even only three colors and winter and summer two characters, this can make the same bottle of gas, In different pressure relief valve on the pressure gauge pointer indication has a big difference. Some pressure gauges have a short range, the pointer has been hitting the head, some pressure gauges have a long range, the pointer has never pointed to the head.
Post time: Sep-15-2022