DVA20-DVG20 are Commercial’s VA and VG model valves. First of all these valves are contemporary versions of the well-proven A20 unit which has provided reliable control of fluid power for over 50 years. The VG model valves are made from compacted graphite, a high strength iron alloy. As a result these valves are rated at 3500 PSI. VA model valves are cast from grey iron and consequently these valves are rated less than the VG model at 2500 PSI.
DVA20-DVG20 valves come with several standard features. These features contribute to the it’s outstanding performance. Symmetrical timing makes changing over from left-to-right hand operation simple. The only thing needed to do is remove the spool and re-insert it in the opposite direction. Furthermore spool seals are fitted in counter bores allowing for easier maintenance and smoother spool operation. These features combined with the extensive range of available spool options, make these valves among the most versatile on the market.
The valves have a built-in full flow relief valves. They also have parallel and series circuits in one bank. The DVA20-DVG20 valves can be controlled through manual, hydraulic, electric, or pneumatic operation. They also have sectional construction giving them maximum flexibility in their use. The ability to change the spool around allows for right and left hand valve assembly. Finally they have low spool effort, hence improved metering.
The DVA20-DVG20 can handle a flow of up to 40 gallons per minute. The maximum operating pressure for the DVA20 is 2500 psi and 3500 psi for the DVG20.
The Inlet section has three choices. These choices are port size, type of ports, and finally an inlet relief valve or an inlet plug(no relief). The type of ports are either pipe thread, o-ring boss straight thread, or 4 bolt flange. Once chosen all the sections will have the same port type.
There are three choices for the work sections spool applications. First of all is the cylinder type spool application (A and B work ports are blocked in the neutral position). Next is the motor type spool application (A and B work ports are open to the tank in neutral position). Finally is the single-acting cylinder type spool application (The A work port is blocked in neutral and has no B work port).
Spool Position Control
There are three spool position control choices. First of all is the 3 position spring return to neutral. Also available is the detent in 3 positions. Finally there is the rotary friction detent variable from A position through B position.
There are four choices for the spool actuators. First is the manual level metering. Next is the rotary level metering option. Another of the choices is the hydraulic pressure actuating option(on or off, proportional pressure metering, or solenoid controlled/pressure actuated). Finally is the air pressure actuating option(on or off, proportional pressure metering, or solenoid controlled/pressure actuated).
There are two choices for the outlet section. First is the standard choice(oil flow is directed to the tank when spools are in neutral and the A or B position). Finally is the power beyond choice(oil flow is directed to the power beyond port when spools are in the neutral position and back to tank when spools are in the A or B position).