LINK Systems Omni II Automatic Setups Module - Manual (Page 20)

October 16, 2008 Manual Version 1.1
3-6
below a minimum value set by the manual regulator (as long as there is shop air
pressure). This prevents cushion drift down when control power is off with its
associated lost die pins below the press bolster and lost time while they are
recovered. This valve also allows the cushions to be adjusted using the manual
regulator path if the automatic system fails, allowing the press to be operated until
the automatic system is restored. When the automatic system is on, the manual
regulator on this valve system must not be set higher than the lowest pressure that
the automatic system is to provide, because the automatic valves will try to dump
while the manual regulator fills if the automatic setpoint is lower than the manual
regulator pressure.
Figure 3-6 Type "B" Valve Configuration
Type “C”
An integrated Fill/Dump valve with a manual regulator, check valve, and LOX
valve, and a four-way valve that selects whether the pressure is set by the
automatic system or the manual regulator as shown in Figure 3.7 for cushion and
counterbalance adjustment. Unlike the type “B” valve, the manual regulator can
be set to any allowable pressure without interfering with automatic pressure
adjustment. It does not have to be a minimum pressure. This system is ideal for
press counterbalance systems as the manual regulator can be set to balance the
heaviest die used on the press. When the OmniLink II Press Automation Control
Automatic Setup module is powered off, the valve automatically reverts to at least
the pressure set by the manual regulator. If there is an air leak in the
counterbalance system, the manual regulator keeps the system charged to support
the weight of the die.