Product Name:Spool valve
Handles higher fluid pressure than most other valves
Automatic suck-back after every dispense cycle
Suitable with moisture sensitive materials
Suitable with UV materials (TS941 Series and TS5322D)
The valve body contains spool valves which can be positioned manually or by hydraulic pressure or by springs.
Spool valves can be positioned manually, or by springs, or by pressure, and in many applications have lands of different diameters.
In this example, the different diameters result in a larger face area on land 1 than on land 2.
This is known as a differential area and when fluid under pressure enters at port B, this differential area creates a differential force.
This moves the valve to the left since the force acting on land 1 is greater than the force on land 2. Alternatively, the valve could be moved by admitting fluid at port C.
In both cases the valve movement allows previously blocked fluid at D to flow between lands 3 and 4 to exhaust at E or to pass to some other part of the system. If fluid pressure is removed from C the valve will remain stationary.
Even if fluid is admitted at port A, no movement can occur as the areas on lands 2 and 3 are equal and both generate an equal force.
The valve can only be moved back to its original position by introducing spring pressure or fluid pressure on the left hand side of land 1.