Piston Cylinder Systems

Our Piston Cylinder System modules utilizethe time-tested Boyd and England design for experiments up to 35 kbar and2000°C.  Shown here is a Rocklandpiston-cylinder system configured in one of our 250 ton presses.

The stack components are above and belowthe pressure vessel, shown here with a set of handles which allow for easymaneuverability. Press dimensions are 72"h x 36"w x 30"d.

Rockland pressure vessels and presses foruse up to 35 kbar are available. We supply presses of several sizes, dependingupon your needs, including table-top units.

A Rockland piston-cylinder system consistsof a press, pressure vessel, stack components and associated hydraulic controlsystems. A simple schematic cross-section of an apparatus is shown in thediagram below. In the diagram, the end load ram and main hydraulic ram are partof the press (not shown), while the remainder of the components, excluding thepressure vessel, are part of the "stack."

The heart of the apparatus is the pressurevessel, which contains a tungsten carbide (WC) core supported by concentricrings of hardened steel, following the time-tested Boyd and England design. Thesample assembly (red) is compressed in the core of the vessel by a WC piston(brown), driven by a WC push piece (dark grey). The force is provided by themain hydraulic ram acting against the sample assembly and stack top plate,which is confined by an end load applied by the upper hydraulic ram.

Upon application of the end load, thesample is pressurized in minutes with an electrically-operated hydraulic pumpdriving the main ram. The system is calibrated by measuring the pressuredependence of some material property (e.g., resistance) through the well-establishedphase transitions of different materials. Temperatures as high as 2000°C ormore can be achieved by passing a current through a cylindrical heater in thesample assembly. Although not explicitly depicted in the diagram, coolantcirculating through the stack top plate and bridge during high temperatureoperation is used to minimize thermal stresses in the pressure vessel. Inaddition to the press and hardware shown above, Rockland can supply bothpressure and temperature controllers for your experiments.