Manufacturer: Eagle Industry Co., Ltd.
Model: DGS

Features

• Gas-lubricated
• Unidirectional or bidirectional available
• Ready-to-fit cartridge unit
• Single, Dual, Tandem and Tandem with intermediate labyrinth available

Specification

Standards and approvals

• NACE

Materials

• Seal face: Silicon carbide (Q1) with DLC coating
  Seat: Silicon carbide (Q1) with DLC coating
  Secondary seals: FKM (V)*
  Metal parts: 1.4006 (SS410) or other stainless steels
• * Or other materials depending on product gas composition.

Operating range

• Pressure: p = 0 … 100 bar (1,450 PSI)
  Temperature: t = -20 °C … 200 °C (-4 °F … 392 °F)
  Sliding velocitiy: vg = 0.6 … 200 m/s (2 … 656 ft/s)

Recommended applications

• Oil and gas industry
  Refining technology
  Petrochemical industry
  Hydrocarbon gas
  Ammonia
  Nitrogen
  Air
  Centrifugal compressors
  Turbo expanders
  Blowers

Installation, Details, Options

• Separation seals as labyrinths, contacting (CSE), non-contacting (CSR) or aerostatic (CobaSeal) bushing seals are optionally available.

Product variants

• DGS Tandem seal
  Application: Where small product leakages of process gas are admissible, e.g. on gas pipeline compressors. Seal on the atmosphere side acting as a safety seal.
• The tandem arrangement provides a particularly high degree of operational safety. The seal on the product side and the seal on the atmosphere side are able to absorb the complete pressure. Under normal operating
  conditions the full pressure is reduced only by the seal on the product side. The space between the seal on the product side and the seal on the atmosphere side is cleared by a connection “B” to the primary vent (flare).
• The pressure to be sealed by the seal on the atmosphere side equals the primary vent pressure, so the leakage to the secondary vent (atmosphere) is very low. If the main seal fails, the second seal acts as a safety seal.
• DGS Tandem seal with intermedia labyrinth
  Application: Where product leakages to the atmosphere as well as nitrogen leakages (from a
  dual seal) to the product are inadmissible, e.g. on H2, ethylene or propylene compressors. With this arrangement the pressure to be sealed is reduced via the primary seal on the product side and the entire process gas leakage is discharged via connection “B” to the primary vent. This is ensured by supplying the atmospheric side seal with secondary seal gas (nitrogen) via connection “C”. The pressure of the secondary seal gas ensures that nitrogen flows via the
  labyrinth to the primary vent connection “B” together with the complete process gas leakage.
• DGS Dual Seal
  Application: Where product leakages to the tmosphere are inadmissible and tandem arrangements are not suitable because of too small product gas pressures. Buffer gas leakages into the product must be admissible (buffer pressure p3 > p1). This seal is used when a neutral buffer gas of suitable pressure is available. Typical applications are to be found mainly in the chemical industry, e.g. on HC gas compressors. A buffer gas, e.g. nitrogen, is fed between the seals via connection “C” at a higher pressure than the product pressure. One part of the buffer gas leakage escapes to the atmosphere side and the other part to the product.