DGS

DGS20
Seals of the DGS20 series are the standard for medium pressures up to 120 bar (1,740 PSI). They have proven their suitability in thousands of applications worldwide. The seals are very rugged and are based on a mature design concept.

Operating range
Shaft diameter:
d = 24.5 … 102,4 mm (0.96“… 4.04“)
Pressure: p = 20 … 120 bar (290 … 1,740 PSI)
Design temperature:
t = -46 °C … +230 °C
(-51 °F ... +446 °F)
Sliding velocity:
vg = up to 227 m/s (744 ft/s)

Materials
Seal face: Silicon carbide with DLC coating; optionally available with DiamondFace coating
Seat: Silicon carbide with DLC coating; optionally available with DiamondFace coating
Secondary seals: FKM or other elastomers depending on product gas composition
Metal parts: 1.4006 or other stainless steels

DGS22
The DGS22 seal series is the new standard for single shaft centrifugal compressors with sealing pressures up to 120 bar (1,740 PSI). The series has an established and robust design with standardized core parts. Furthermore, it is characterized by a short axial length and very low leakage rates. The DGS22 is an advancement of the DGS20 series.

Operating range
Shaft diameter:
d = 102,5 mm … 360 mm (4.04“… 14.17“)
Pressure: p = up to 120 bar (1,740 PSI)
Design temperature:
t = -46 °C … +230 °C
(-51 °F ... +446 °F)
Sliding velocity:
vg = up to 220 m/s (656 ft/s)

Materials
Seal face: Silicon carbide with DLC coating; optionally available with DiamondFace coating
Seat: Silicon carbide with DLC coating; optionally available with DiamondFace coating
Secondary seals: FKM or other elastomers depending on product gas composition
Metal parts: 1.4006 or other stainless steels

DGS21
Seals of the DGS21 series offer the lowest leakages of the elastomer-based DGS platform. They are therefore suitable for applications with high demands on low leakage. As some parts of the high-pressure PDGS series are used in the DGS21 series, the seal can be applied up to a pressure of 160 bar (2,320 PSI).

Operating range
Shaft diameter:
d = 51.5 … 262 mm (2.03“… 10.31“)
Pressure:
p = 50 … 160 bar (725 … 2,320 PSI)
Design temperature:
t = -46 °C … +230 °C
(-51 °F ... +446 °F)
Sliding velocity: vg = up to 227 m/s (744 ft/s)

Materials
Seal face: Silicon carbide with DLC coating
Seat: Silicon carbide with DLC coating
Secondary seals: FKM or other elastomers depending on product gas composition
Metal parts: 1.4006 or other stainless steels

DGS25
The DGS25 gas seal series was developed for use in high-speed geared turbo compressors. Due to the special lightweight construction of the core parts and the extremely short working length design, the DGS25 covers the full spectrum of market requirements: Operation at extremely low pressures, robustness to machine vibrations and low impeller overhang. Dangerous stimulation of the core parts by omnipresent machine vibrations are prevented by their low mass or inertia. In addition, the overhang of the impeller from the bearing can be greatly reduced, thus decisively improving rotor dynamics. This enables mechanical run tests without pressure up to 227 m/s seal circumferential speed. No complex pressurization is necessary, open loop tests are child's play. In addition to the use in geared turbo compressors, the DGS25 can also be used in very short installation spaces. This is particularly often the case when compressors are upgraded from oil to gas seals to reduce emissions and operating costs and increase safety and availability.

Operating range
Shaft diameter:
d = 24.5 … 102.5 mm (0.96“… 4.03“)
Pressure:
p = up to 50 bar (… 725 PSI)
Design temperature:
t = -46 °C … +230 °C
(-51 °F … +446 °F)
Sliding velocity: vg = up to 227 m/s (744 ft/s)

Project specific special designs possible

Materials
Stationary seal face: Silicon carbide with DLC-coating, DiamondFace-coating optional
Rotating seal face (Seat): Silicon carbide with DLC-coating, DiamondFace-coating optional
Secondary seals: FKM or other elastomers, depending on product gas composition
Metal parts: 1.4006 or other stainless steels


Drawing items
1 Shortened stationary seal face
2 Shortened rotating seal face (seat)
3 Thick dynamic O-ring
l1K Shortened installation space

A Seal gas supply
B Vent
C Separation gas supply

DGS32
Due to the cost effective design, simple components and a hard/soft sliding material combination the DGS32 represents a reliable and economical solution for applications with partial contact of seal faces. This include, for example, slow-roll and turning operation (steam turbine driven compressors) or long and very frequent start/stop cycles.

Operating range
Shaft diameter:
d = 27.4 … 406 mm (1.08"… 15.98")
Pressure: p = 0 … 120 bar (0 … 1,740 PSI)
Design temperature:
t = -46 °C … +230 °C
(-51 °F ... +446 °F)
Sliding velocity:
vg = 0 … 140 m/s (0 … 295 ft/s)

Materials
Seal face: Carbon graphite
Seat: Silicon carbide
Secondary seals: FKM or other elastomers depending on product gas composition
Metal parts: 1.4006 or other stainless steels