Reasons for lack of compressor displacement

Insufficient displacement is one of the compressor failures, mainly caused by the following reasons:

1. Malfunction of the intake filter: fouling and clogging, reducing the exhaust volume; the suction pipe is too long and the diameter is too small, which leads to an increase in the suction resistance and affects the air volume. Clean the filter regularly.

2. Compressor speed reduces displacement: the compressor is used improperly because the compressor displacement is at a certain height.

3. Cylinders, pistons and piston rings are severely worn, exceeding the tolerance range, increasing related clearances and leakage, and affecting displacement. In normal wear, the wearing parts such as piston ring should be replaced in time. If the installation is not correct and the gap is maintained improperly, it should be corrected according to the drawings. If there is no drawing, you can get experience materials. If it is a cast iron piston, the circumferential clearance between the piston and the cylinder is 0.06/100~0.09/100 of the cylinder diameter. As for the aluminum alloy piston, the clearance is 0.12/100~0.18/100 of the diameter of the gas path. The smaller value of aluminum alloy pistons can be used for steel pistons.

4. The stuffing box is not tight, causing air leakage and reducing air volume. One reason is that the stuffing box itself was not up to standard when it was made. Secondly, it may be that the piston rod and the center of the stuffing box are not aligned correctly during installation, causing wear, strain, and air leakage. Under normal circumstances, the stuffing box is filled with lubricating oil, which can be lubricated, sealed and cooled.

5. The influence of compressor suction and discharge valve failure on displacement. Metal fragments or other debris dropped between the valve seat and the valve plate of the air valve, resulting in loose closing and air leakage. This not only affects the displacement, but also affects the changes in pressure and temperature between stages. This problem may be due to, first, manufacturing quality problems, such as warping of the valve plate, and second, serious wear of the valve seat and valve plate leading to air leakage.

6. The tension spring force of the air valve does not match the air spring force. If the elastic force is too strong, the valve plate will slowly open, but if the elastic force is too weak, the valve plate will not close in time, which will not only affect the air volume, but also affect the increase in power, and affect the service life of the valve plate and the tension spring. At the same time it will also affect the changes in gas pressure and temperature.

7. Improper air valve pressure. If the compression force is small, the air will leak, but it must not be too tight, which will deform and damage the valve cover. Compressive force can generally be calculated by the following formula: p=kπ/4 D2P2, d is the diameter of the valve cavity, P2 is the larger gas pressure, k is a value greater than 1, generally 1.5~2.5, when low pressure k=1.5~2.0, high pressure When k=1.5. If the air valve fails, the valve cover will heat up and the pressure will be abnormal.