Hydraulic piston

The implementation of high-pressure reaction cells in conjunction with UFIV surface science techniques allowed the first tme in situ postmortem studies of a heterogeneous catalytic reaction. These cells penult exposure of a sample to ambient pressures without any significant contamination of the UFIV enviromnent. The first such cell was internal to the main vacuum chamber and consisted of a metal bellows attached to a reactor cup [34]- The cup could be translated using a hydraulic piston to envelop the sample, sealing it from... 

Hydraulic piston-type compactors for collection vehicles, on-site compactors, and transfer-station compactors roll crushers used to fracture brittle materials and to crush tin and aluminum cans and other ductile materials... 

The zippered bellows that protect the hydraulic piston against drippings should be checked for wear and tear. 

The use of hydraulic systems for the setting, operation and control of machine tools has increased significantly. Hydraulic mechanisms being inter-linked with electronic controls and/or feedback control systems. In machine tools, hydraulic systems have the advantage of providing stepless and vibration-less transfer of power. They are particularly suitable for the linear movement of tables and slideways, to which a hydraulic piston may be directly coupled. 

Air from a cylinder at pressures up to about 10 bar (150 psi) is applied to a gas piston that has a relatively large surface area. The gas piston is attached to a hydraulic piston that has a smaller surface area. The pressure applied to the liquid = gas pressure x area of gas piston/area of hydraulic piston. With 10 bar inlet pressure and a 50 1 area ratio, the hydraulic pressure obtained is 500 bar (7500 psi). On the drive stroke, the outlet valve on the pump head is open to the column and the inlet valve closed to the mobile phase reservoir. At the end of the drive stroke, the air in the chamber is vented and air enters on the other side of the gas piston to start the return stroke. On the return stroke the outlet valve closes, the inlet valve opens and the pump head refills with mobile phase. The pump can be started and stopped by operation of a valve fitted between the cylinder regulator and the pump. 

Pressures from 1 bar to 1 kbar can be attained by using a hand-operated hydraulic piston, similar to what is used in an automobile repair shop. Above 1 kbar, pressure intensifiers can boost these pressures tenfold, reaching about 10 kbar. Both hydraulic pistons and pressure intensifiers require a hydraulic fluid (heavy oil at room temperature, n-pentane down to 77 K or so) which can be compressed isotropically for some pressures, talcum powder can act as an almost isotropic pressure-transmitting medium. If higher pressures are needed, the demand for isotropic compression must be abandoned, and anisotropies creep in. 

Figure 34 Freeze-drying plant condenser and shelves cooled with LN2. Clean-in-place system in chamber and condenser. 1, LN2 inlet to condenser and heat exchanger 2, N2 outlet from the condenser and heat exchanger 3, heat exchanger for the brine in shelves 4, brine to and from shelves 5, pressure plate for stoppering of vials 6, piston rod with bellows 7, hydraulic piston for 5 and 6 8, hydraulically operated valve 9, hydraulic system 10 and 13, water and steam inlet 11, pumping system 12, water outlet. (AMSCO Finn-Aqua GmbH, D-50354 Hiirth, Germany.)...

In transfer molding, pressure is used as the independent control variable because most presses are not equipped with speed controllers for the hydraulic piston. The general range of transfer pressures at which fluoropolymers approach critical shear rates is 15-25 MPa. Filling the mold in the super shear mode results in adverse effects on the properties of the molded part. 

The Mitsubishi system uses two cams, one for low the other for high speed range. Cams are driven, or not driven, according to the position of a hydraulic piston (fig.4). Here you can have three situations. At low torque and low running conditions (fig.5) two cylinders are discoimected (their valves remain closed). 

The principle of the DAC packing is to transfer the slurry into the column and then pack using a hydraulic piston. To be able to perform a good DAC packing, the column volume should be sufficient to receive all the slurry or an extension tube should be attached to the column body (Figure 4.27). 

Most biologists are familiar with the use of animal models to study human diseases. Although a disease that occms in humans may not be foimd in exactly the same form in animals, often an animal disease shares enough attributes with a human counterpart to allow data gathered on the animal disease to he used to make inferences about the process in humans. Mathematical models describing the forces involved in musculoskeletal motions can be built by imagining that muscles are combinations of springs and hydraulic pistons and bones are lever arms, and, often times. 

Focus in the following will be on the description of hydraulic piston extruders as employed in the ceramic industry and for the extrusion of hard metal, since the application in both cases is very similar and several interesting solutions have evolved for the shaping of hard metal with the use of piston extruders. 

A hydraulic piston, B hydraulic system, C base frame, D receiver,... 

In contrast to this the press frame is subject to a permanent dynamic load as it must absorb the press forces which develop during extrusion between the hydraulic piston and the receiver. 

As part of the Deep Sea Drilling Project, a hydraulic piston corer (HPC) was developed which can be used with motion-uncompensated drill pipe (Walton et al., 1982) (Figure 5.10). This is a proven deep-water sampler that has taken high-quality 63.5-mm-diameter soil samples in water depths greater than 2078 m. Sample recovery is generally 90% or more which is... 

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