DGS-PT is a dry-running gas seal,it is a tandem gas seal,cartridge design,Uni-directional or bidirectional capability.The primary seal is a contact-type mechanical seal of DGS-PT, while the secondary seal is a non-contact dry gas seal. The primary seal operates with the process medium itself, and the secondary seal operates with an external buffer gas.
Under normal conditions, the primary seal takes the full process pressure, and the secondary seal operates at low pressure or near atmospheric pressure. If the primary seal fails completely, the secondary seal acts as the main seal and can ensure safe operation for at least 8 hours.
Pressurized buffer gas is supplied to the secondary seal and isolated by a labyrinth seal, preventing leakage from the primary seal from contaminating the secondary dry gas seal. The buffer gas also carries the leaked process medium from the primary seal to the flare system or a collection tank for centralized discharge, ensuring safety and environmental protection. In addition, the pressurized buffer gas reduces vaporization of the process medium at the primary seal faces, improves lubrication of the mechanical seal, and extends the seal service life.
Key Features
API 682 2CW-CS Tandem Configuration
DGS-PT combines a contact-type mechanical seal on the process side with a non-contact dry gas seal on the atmospheric side. The tandem arrangement provides a secondary sealing stage for improved containment of process fluids.
Pressurized Buffer Gas System
Pressurized buffer gas is supplied to the secondary dry gas seal to support stable sealing conditions and help isolate the secondary seal from process-side leakage.
Labyrinth Isolation
A labyrinth seal separates the primary and secondary sealing stages, helping prevent process leakage from reaching and contaminating the secondary dry gas seal.
Secondary Sealing Protection
If the primary mechanical seal fails completely, the secondary dry gas seal can take over the main sealing function and provide safe operation for at least 8 hours.
Cartridge Design
The cartridge construction integrates the seal components into a compact assembly, simplifying installation, removal, and maintenance.
Unidirectional or Bidirectional Rotation
DGS-PT can be configured for unidirectional or bidirectional rotation according to the requirements of the centrifugal pump.
Applications
DGS-PT is suitable for centrifugal pumps used in:
- Refining and Petrochemical Industry
- Chemical Industry
- Oil and Gas Industry
- Coal Chemical Industry
It is suitable for applications where reliable containment of process fluids, controlled leakage discharge, and reduced atmospheric emissions are important.
API 682 Piping Plans
Process Side
- API 682 Plan 11
- API 682 Plan 13
- API 682 Plan 21
- API 682 Plan 32
Atmospheric Side
- API 682 Plan 72
- API 682 Plan 75
- API 682 Plan 76
The appropriate piping plan should be selected according to the process medium, pressure, temperature, operating conditions, and equipment requirements.
