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

Features

• Gas-lubricated
• Bi-directional
• Ready-to-fit cartridge unit
• Single, double, tandem seal and tandem with intermediate labyrinth available

Specification

Standards and approvals

• NACE

Materials

• Seal face: Carbon graphite antimony impregnated
  Seat: Ductile stainless steel with DM-TiN coating
  Secondary seals: FKM (V) or other materials
  depending on product gas composition
  Metal parts: 1.4006 or other stainless steels.

Operating range

• Pressure: p = 0 … 50 bar (0 … 725 PSI)
  Temperature: t = -30 °C … 200 °C (-22 °F … +392 °F)
  Sliding velocity: vg = 0.6 … 200 m/s (2 … 656 ft/s)

Recommended applications

• Oil and gas industry
  Refining technology
  Petrochemical industry
  Hydrocarbon gas
  Nitrogen
  Air
  Centrifugal compressors
  Dry process gas screw compressors
  Blowers

Product variants

• MDGS 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 differential. 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 flare. The pressure differential to be sealed by the seal on the atmosphere side equals the flare pressure, so the leakage to the atmosphere side or to the vent is very low. If the main seal fails, the second seal acts as a safety seal.
• MDGS Tandem seal with intermediate labyrinth
  Application: Where product leakages to the atmosphere as well as buffer gas leakages to the
  product are inadmissible, e.g. on H2, ethylene or propylene compressors. With this version the
  product pressure to be sealed is reduced via the seal on the product side. The entire process gas leakage is discharged via connection “B” to the flare. The seal on the atmosphere side is pressurized with buffer gas (nitrogen) via connection “C”. The pressure of the buffer gas ensures that a current flows via the labyrinth to the primary vent outlet.
• MDGS 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.