Synertech Stock
High pressure GB
Variant of the G type designed to withstand high pressures, featuring a special sealing lip design and a metal casing completely covered in rubber.
Product codes
Details
The GB series rotary shaft seals, also known on the market as high-pressure oil seals or BABSL type with hydrodynamic grooves, are special dynamic seals designed to operate under high internal back-pressure. The profile features a short, rigid main sealing lip, supported by a garter spring and provided with micro-grooves on its back surface to optimize fluid circulation. The smooth rubber-covered outer casing ensures static stability within the housing and counteracts the axial thrust generated by hydraulic pressure.
Type GB Standard
Reinforced single-lip profile with a short cross-section, internal garter spring, hydrodynamic micro-grooves on the inclined dynamic surface and a completely smooth elastomer outer diameter.
Type GB/DL
Variant equipped with a second auxiliary front dust lip on the air side, suitable for applications simultaneously exposed to internal hydraulic back-pressure and environmental contamination.
Materials and operating conditions
| Material / Compound | Peripheral speed | Temperature | Max pressure |
|---|---|---|---|
| NBR Nitrile rubber 70 / 80 ShA |
Up to 12.0 m/s | −30 / +100 °C |
Up to 1.0 MPa continuous 10 bar, with peaks up to 1.5 MPa depending on rotational speed |
| FKM Fluoroelastomer / Viton |
Up to 35.0 m/s | −20 / +200 °C | — |
Internal structure
Mineral and synthetic hydraulic oils, high-viscosity fluid gear lubricants, greases and oil emulsions.
Main features
Short section with reinforced base
The lip geometry reduces the flexible area exposed to hydraulic pressure. The reinforced base counteracts outward lip deformation and keeps the sealing edge in contact with the shaft surface even at pressures up to 10 bar.
Hydrodynamic micro-grooves
The inclined back surface of the dynamic lip features molded helical micro-grooves. During shaft rotation, these act as a viscous-dynamic micro-pump, promoting the return of oil towards the inside of the housing and limiting pressure-induced micro-leakage.
Smooth rubber-covered outer casing
The full elastomer coating ensures static sealing against the housing. It compensates for thermal expansion of the metals and counteracts axial displacement caused by fluid pressure.
Advantages of the GB profile
Sealing under hydraulic load
The profile is designed to withstand continuous pressures up to 1.0 MPa and can reduce the need for external leakage-oil drainage systems.
Minimum hydrodynamic friction
The structural rigidity of the short profile limits the increase in dynamic contact area under pressure, reducing localized heat generation and wear on the shaft surface.
Installation precision
The outer rubber coating reduces the mechanical force required for press-fitting into the housing and limits the risk of damage or scoring in seats made of aluminium or soft metals.
Typical applications
- Front transmission shafts and hubs for industrial and mobile rotary hydraulic motors
- High-pressure hydraulic gear or vane pumps exposed to back-pressure peaks
- Rotary screw air compressors, industrial vacuum pumps and pressurized process agitators
- Industrial gearboxes, speed reducers and differentials with internal air pressure or sealed housings
- Transmission systems for heavy mobile hydraulics, agricultural machinery and earthmoving equipment
International standards
Construction dimensions, geometric tolerances and installation dimensions in compliance with international standards and construction specifications for ISO 6194 hydraulic pumps and reinforced BABSL-type high-pressure series.
Available configurations
Type GB Standard
Reference configuration for standard mobile hydraulics and hydraulic motors operating at medium temperatures. It provides resistance to hydraulic pressure and long-term axial stability at a competitive cost.
Type GB Premium
Configuration for applications exposed to high peripheral speeds, up to 35 m/s, or subject to continuously high temperatures. The fluoroelastomer provides greater resistance to synthetic lubricants and to heat generated during operation under pressure.
Market equivalents
| Manufacturer | Type GB Standard - NBR | Type GB Premium - FKM / Viton |
|---|---|---|
| Net Seals | Pressure Oil Seal Series BABSL / GAP / GB | Viton Pressure Oil Seal Series BABSL / GB FKM |
| Freudenberg (Simrit) | Simmerring® BABSL Hydrodynamic Profile | Simmerring® BABSL FKM Hydrodynamic Profile |
| Parker Prädifa | TCN / BP Pressure Profile | TCN (FKM) Profile |
| Kastas Sealing Technologies | K33 / K34 Hydrodynamic Profile | — |
| Corteco | Pressure Oil Seal Series with Hydrodynamic Grooves | — |
| Dichtomatik | — | BABSL FKM Helix Profile |
| SKF | — | Viton Hydrodynamic High-Pressure Seals |