There was a time, almost a generation ago, when the HH range of cylinders used an array of (normally) four metallic rings as the piston seal. Their function was much along the lines of the ones used in a car engine to this day.

These rings were inert to more or less anything the world threw at them. Heat was an easy task, aggressive fluids no problem and the working surface was so hard that the tube was more likely to wear over time than the seals were to lose their size.

While we at Sheffer don't provide hydraulic power units, these are invariably used in a majority of hydraulic applications to drive our cylinders. By looking at the system as a whole, in many cases hydraulics can provide a more cost effective solution especially when long-term energy costs are considered.

Many of our distributors can provide complete solutions and technical assistance regarding power units and a comprehensive hydraulic solution incorporating Sheffer cylinders.