ITT
Engineered Valves, LLC
Page 7 of 24
Technical Manual No. IOT4400F Effective 8/31/2018
REV LEVEL B
B.
Close Block Valves (Open Vent)
How the valve is commanded Closed differs between different model numbers.
For T4405F valves:
Deleting voltage from terminal 1 and 2, and applying voltage momentarily across
terminals 2 and 3 for AC Solenoids (Terminals 20 and 21 for DC solenoids)
energizes the exhaust coil and exhausts pneumatic pressure from the cylinder.
CAUTION
Note: Never energize both solenoid coils simultaneously.
Doing so, will permanently damage the coils.
For T4406F and T4407F valves:
Deleting voltage from terminals 1 and 2 for AC Solenoids (Terminals 18 and 19
for DC solenoids) de-energizes the pilot solenoid and exhausts pneumatic
pressure from the cylinder.
For all models:
Upon exhausting the cylinder, both inlet and outlet return springs move their
respective plugs toward their seat rings. First the inlet valve soft seal makes,
halting flow through the assembly, then its metal back-up. The inlet POC switch
trips after the inlet block valve soft seal starts into its seat. Next the vent cage
moves off its post, opening the vent and relieving downstream pressure. Finally,
the outlet valve soft seal, followed by its metal back-up close, completing the
cycle. Two independent blocks are formed between system inlet and outlet, with
the chamber between the block valves ported to vent. The outlet POC switch trips
after the outlet block valve soft seal starts into its seat.
C.
Notes
The standard Versa pneumatic subassembly is equipped with a built in speed
control valve. It is located directly above the cylinder exhaust port and can be
adjusted with a 1/8” hex Allen wrench. Turning the adjustment inward or
clockwise slows the opening speed.
Note: The speed control function has no
effect on closing speed.
