What are the considerations for adjustment of thermal expansion of pneumatic valve?

the thermal expansion of the pneumatic valve adjustment work, must be conducted under the normal operation of the refrigeration equipment. Because the evaporator surface can't place the thermometer, can use the compressor suction pressure as the saturation pressure inside the evaporator, look-up table to get approximate evaporation temperature. With a thermometer to measure the temperature of the muffler, and evaporation temperature contrast to check degree of superheat.
adjustment, if feel too hot too small, can put the adjusting screw clockwise rotation ( That increase the spring force, reducing thermal expansion pneumatic valve open degree, reduce traffic; Conversely, if feel too hot too large, the feed flow is insufficient, can put the adjusting screw in the opposite direction ( Rotate counterclockwise, make traffic increases. Due to the fact that the thermal expansion work pneumatic valve thermal system there exists a certain thermal inertia, the formation of signal transmission lag, run stable rear can be adjusted to the next. Must be careful so that the whole adjustment process, adjustment screw rotation of lap time shoulds not be too much too fast, Straight rod type thermal expansion of the pneumatic valve adjusting screw rotation, degree of superheat changes probably change ~ ℃.