• A mechanical seal is in tandem with a dry gas seal, the mechanical seal is the primary seal and the dry gas seal is backup seal;
• The dry gas seal operates no-contacting so that the primary seal has a certain back pressure, which can effectively prevent the primary seal unstable operation caused by the liquid-film gasification (or vaporization) between the primary seal faces. So the life of the primary seal can be extended greatly;
• Primary leakage can be flared with buffer gas, so the process gas cannot leak out to atmosphere;
• When the primary seal failures, the gas seal can be acted as primary seal;
• Cartridge structure，easy to install and precisely positioning.

HM11C- Tandem Dry Gas Seals P&ID