1. Introduction of refrigerant pressure gauge:

The refrigerant pressure gauge is also called a refrigeration gauge or a fluorine gauge. It is used to measure the current pressure of the refrigeration system. It is mainly used to detect the pressure value of the refrigerant at different stages of the system, and the operating conditions of the user holding the equipment. At present, the accuracy requirement of the refrigerant pressure gauge in our country is 2.5.

Refrigerant pressure gauges are generally divided into "high pressure gauge" and "low pressure gauge", that is, the highest reading value of general "low pressure gauge" is 1.8MPa or 18bar (Figure 1), and the highest reading value of "high pressure gauge" is 3.8MPa or 38bar (Figure 1). 2)

Second， read the pressure value

1. The value of the outermost circle of the low pressure meter is the value of MPa. If the pointer points to "3", the current pressure is 0.3MPa, and the value of the second circle of the low pressure meter from the outside to the inner is 1kg/cm2

2, the value of the red letter in the innermost circle of the high pressure meter is the value of bar, if the pointer points to "20", that is, the current pressure is 20 bar

3. Conversion of different pressure units

1MPa≈101kg/cm2≈10bar≈145Psi

Three, read the temperature value

1. Low pressure meter, counting from outside to inside, the second circle blue R407c temperature value, unit ℃ Celsius

The 4th circle black R22 temperature value, unit ℃ (Celsius)

If a chiller uses R22 as the refrigerant, the condensation temperature corresponding to the low pressure of 0.5MPa during operation is about 6 degrees

If a chiller uses R134a as the refrigerant, the condensation temperature corresponding to the low pressure of 0.3MPa during operation is about 9 degrees

2, high pressure meter, counting from inside to outside

the first circle, black, pressure value, unit MPa (megapascal) or bar

2nd circle black, R404A temperature value, unit ℃ (Celsius)

the 3rd circle, blue, R134a temperature value, unit ℃ (Celsius)

the 4th circle, green, R22 temperature value, unit ℃ (Celsius)

Like a chiller using R22 as the refrigerant, the condensation temperature corresponding to the high pressure 1.8MPa during operation is about 50 degrees

Like a chiller using R134a as the refrigerant, the condensation temperature corresponding to the high pressure 1.4MPa during operation is about 55 degrees

Additional explanation:

1, MPa MPa, 1kg/cm2 kilogram force/square centimeter

2. Different pressure gauges may have different pressure units. Before reading the pressure, look at the logo on the front dial

3. Chillers and air conditioners are generally used: R22, R407C, R134a;

Low temperature unit R22, R404A; 　Household air conditioner R22 or R410a;

Automotive air conditioner: R134, R12.

4. When the compressor is not running, the pressure is the equilibrium pressure, that is, the high and low pressures are the same, and the pressure value

corresponds to the ambient temperature or the water temperature of the water tank.

Such as: R22 　 when the ambient temperature is 30 degrees, the balance pressure of the pressure gauge is about 1.1MPa

Such as: R22 　 when the ambient temperature is 10 degrees, the balance pressure of the pressure gauge is about 0.6MPa