The SZ series water ring vacuum pumps and compressors are used to draw or compress air and other non-corrosive gases that are insoluble in water and do not contain solid particles, in order to create vacuum and pressure in a closed container. However, a small amount of liquid is allowed to be mixed in the inhaled gas. It is widely used in the fields of machinery, petrochemicals, pharmaceuticals, food, sugar manufacturing and electronics. Because the compression of gas is isothermal during operation, it is less likely to cause danger when compressing and suctioning flammable and explosive gases, so its application is more extensive.