Liquid ring vacuum pump normally has two kinds of sealing means: gland packing, mechanical seal.
Gland packing is an ideal choice to pump air (nontoxic), for its cost-efficiency, easy to maintain or repair, and posseses a simple structure. Becuase its sealing performance is not very ideal, existing leakage, it is adopted for process requiring low vacuum and is prohibited to suck toxic or explosive gas.
The mechanical sealing has a long lifetime, excellent sealing performance with little air leakage. So it becomes the primary option for petroleum and chemical industry. with it, pump can be used to suck strong corrosive gas or toxic gas.
While mechanical seal is devided into single end mechanical seal and doulb end one.
Single end mechanical seal is mostly adopted, for its easy maintenance and simple operation, as well as cost effective. Its sealing liquid is working liquid connected from pump chamber through bearing, no need of separate tubes and saving cost.
The double end mechanical seal is always adopted on condition when working medium contains corrosive content. To avoid corrosive working liquid corrode the mechanical seal, a set of separate tube is necessary for isolated water supply. Hence it’s more costly compared with other sealing means.
The selection of sealing means is based on the working medium(content of sucked gas). If the suction medium contains toxic factors, the mechanical sealing should be the irreplaceable choice.