Glossary

Ultrasonic - It's a vibration with frequency higher than that normally audible to human ear. .

Unloading Valve - It's a Valve that by-passes flow to reservoir when set pressure is maintained on pilot port. .

Unload - Its releasing flow to reservoir. .

Vacuum Press - It's a hydraulic press that features vacuum enclosed platen working areas for removing air, gas vapors and fumes during forming process. This vacuum style hydraulic press ensures consistent material flows and precise control over temperature and pressure. .

Vacuum Pressure - Its deficiency of fluid/flow resulting from too low temperatures, too high suction velocity or incorrect fluid viscosity. It leads to suction difficulties as well as pump damages. .

Valve, Proportioning - This valve is fixed differential pressure reducing valve having fixed spring and fixed differential area. Its used in braking systems for limiting magnitude of pressure to rear brakes. .

Vena Contracta - Its region of smallest cross section in fluid stream where fluid emerges from an orifice, it tends to contract in cross section reaching minimum and then expanding back to fill conduit. .

Viscosity Index - It's a measure of viscosity-temperature characteristics of fluid compared to two arbitrary reference fluids. .

Window Frame Hydraulic Press - It's a hydraulic press that has large open feed area/window that is especially designed for larger dies or where access to work area is important. These window style hydraulic presses offer minimal deflection as well as optimal cross head parallelism. .

Work Height - Its the distance from floor to top of bolster. .

Water Hammer - It's a process where there is vibration of conduit in fluid system because of rapid changes in liquid velocity due to valve closure. .

Wear Ring - Its an element that is used for preventing cylinder seals from being crushed and metal-to-metal contact from occurring through maintaining seal concentricity when side loads exist. .

Wobble Plate - It's a rotating canted plate in axial type piston pump that pushes pistons into their bores as it "wobbles."