SDF | series

Replacing Stuffing Box Packings and Lip Seals in Demanding Applications

Leaking despite maintenance?

Then the problem isn’t with the seal – it’s with the sealing principle.

In many production processes, traditional sealing systems such as stuffing box packings or lip seals reach their limits. Especially with solids, viscous media, or dynamic load cycles, unstable sealing conditions arise – with leakage as a direct result.

The solution is not “better adjustment,” but a different sealing principle.

Typical real-world scenarios

Many of our customers come to us with exactly these questions:

Replacement for packing glands in screw conveyors or mixers

Alternative to lip seals for demanding media

Solutions for recurring leaks in rotating applications

Retrofit concepts without disassembling the shaft

In demanding processes, forces act on the seal that conventional systems cannot compensate for over the long term:

abrasive or inhomogeneous media
viscous substances and solid particles
radial forces and shaft misalignment
changing load conditions

These factors cause sealing surfaces to contact unevenly or partially detach. The result is not uniform wear – but an unstable sealing condition. And it is precisely this condition that causes leakage.

Why packing and lip seals are insufficient here

Conventional sealing systems rely on radial compression – a principle that in practice often leads to constant readjustment, increased friction and temperature, and accelerated wear. The result is declining process stability: leakage is not prevented, but rather managed or accepted as part of operations.

Replacing them with modern sealing systems is particularly advisable when:

Leaks occur regularly

Maintenance and readjustment are part of daily operations

Production processes are sensitive to sealing issues

A complete plant retrofit is not possible or economically viable

Structure of the STASSKOL SDF Series

Solution approach

Stable sealing condition instead of readjustment

With the SDF Dynamic Seal Series, STASSKOL takes a different approach: Instead of radial compression, the system is based on axial sealing action. This creates constant contact pressure even under load changes, while reducing friction and heat generation. At the same time, optimized materials ensure high wear resistance and uniform force transmission throughout the entire system.

Advantages

Limited installation space → individual adaptation possible
Existing interfaces → remain intact
No disassembly required → split design
Complex media → stable sealing geometry

Case studies

See how the switch to stable sealing systems sustainably improves processes through real-world projects
in glass, feed, chocolate, and dairy processing.

Retrofit of screw conveyors in the glass industry

Learn more

Retrofit of a twin-shaft mixer in animal feed production

Learn more

Retrofit of a twin-shaft mixer in animal feed production Retrofit of a conche in chocolate production

Learn more

Retrofit of the screw seal in a mozzarella plant

Learn more

Reduced product loss due to leakage

reduzierte Produktverluste
durch Leckage

Lower maintenance requirements

Lower energy and operating costs

Higher plant availability

Is this suitable for your application?

Not every seal is a standard case. We’ll assess your current situation and evaluate whether a retrofit makes sense – both technically and economically.

Replacing Stuffing Box Packings and Lip Seals in Demanding Applications

Then the problem isn’t with the seal – it’s with the sealing principle.

Typical real-world scenarios

Replacement for packing glands in screw conveyors or mixers

Alternative to lip seals for demanding media

Solutions for recurring leaks in rotating applications

Retrofit concepts without disassembling the shaft

In demanding processes, forces act on the seal that conventional systems cannot compensate for over the long term:

Why packing and lip seals are insufficient here