A tandem dry gas seal is a type of dry gas seal that is used in turbocompressors. Tandem Seal is the most common seal in turbocompressors. The tandem seal is generally used in natural gas applications due to the minimal leakage to atmosphere. The intermediate labyrinth purged with nitrogen (to eliminate fugitive emissions) is nearly always recommended.  The primary vent is between the two seals and usually connected to the flare system.

LP-28 tandem dry gas seal is designed to replace john crane type 28AT  28ST 28EXP 28XP series DGS item. this tandem dry gas seal, with a design pedigree stretching back over many years and evolving gradually, installed and proven in thousands of compressors all around the world and remaining the preferred seal choice for many customers.

these Tandem Seals are non-contacting in operation. During dynamic operation, the mating ring/seat and primary ring/face maintain a sealing gap of approximately 0.0002"/5 microns, thereby eliminating wear. 

LEPUSEAL is a famous top brand for dry gas seal since 1998, manufacturing many kinds of dry gas seal for China big facotries, such as SINOPETRO,  YANGZI REFINERY . and lepuseal also make DGS for many oversea clients like Russia, Iran,  Turkey,  UAE, and keeping very good reputation in dry gas seal field.