In the hydraulic power industry, there is no room for compromise — especially when it comes to municipal equipment. Vehicles such as garbage trucks operate continuously, under enormous loads and in heavily contaminated environments. Every unplanned downtime generates significant costs and logistical headaches for the city.
A customer recently approached us with an unusual challenge. They needed a complete, multi-stage seal kit for a specialised telescopic cylinder responsible for actuating the push plate (ejection wall) in a refuse collection vehicle.
Engineering Challenge: the specifics of a telescopic cylinder
Telescopic (multi-stage) cylinders are characterised by a compact design combined with a very large stroke. Structurally, however, they are far more demanding than standard plunger cylinders. In this particular case, we were dealing with a design featuring full sealing on both the piston and the gland of each individual stage.
We encounter similarly advanced engineering solutions in the cylinders made by the renowned Finnish manufacturer Nummi (now part of the Wipro group), well known for their reliability under extreme Scandinavian operating conditions.
CNC Precision – Perfect Material Match
All critical sealing and guiding components were manufactured in our facility using CNC lathes. Thanks to precision machining technology, we were able to perfectly match seal profiles and select the highest-quality materials suited to heavy-duty working conditions:
| Material | Application | Series | Properties |
|---|---|---|---|
| PU Polyurethane | Wipers, rod seals | WH03A-M, RS09AW-M | Abrasion resistance, high pressure, mechanical contamination |
| PTFE+BR PTFE with bronze | Piston seals | GR01-MPS | Friction minimisation, stick-slip elimination, long service life under pressure |
| POM Polyoxymethylene | Guide rings | GR05-MS, K69, K77, HES | High radial load capacity, dimensional rigidity |
| NBR70 Nitrile rubber | Static O-rings | Ø48 / 67 / 85 / 108 × 3 mm | Oil resistance, full static sealing of connections |
End Result
By combining engineering expertise, analysis of Nummi-type seal geometry, and the capabilities of CNC machining technology, we delivered a product with parameters equal to — and in many respects exceeding — the factory original. The garbage truck was quickly returned to service on the city streets, and the regenerated telescopic cylinder will handle the pressure of hundreds of tonnes of waste for many more seasons to come.
Do you have a machine with non-standard hydraulics?
Original seals unavailable or lead times paralysing your operation? We manufacture custom seals using CNC machining for any type of cylinder — fast, precise, and from the best materials on the market.
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