Manual

31
Fluid Installation
9.4.2. Pneumatic connection for process
valves belonging to series 26xx and
27xx
DANGER!
Risk of injury from high pressure!
• Before dismounting pneumatic lines and valves, turn off the
pressure and vent the lines.
Working connection 2
(connection: A2)
Working connection 1
(connection: A1)
upper chamber
lower chamber
Fig. 32: Pneumatic connection series 26xx and 27xx
The length of this control line should be adapted to the
actuator size because the clearance volumes caused
by the control line can have a negative influence on the
control properties. The following is the case: the smaller the
actuator, the more sensitively the control system reacts to
the length of the pneumatic control line.
Procedure:
Control function A (single-acting actuator):
→ Connect the working connection A1 or A2
4)
of the position con-
troller Type 8791 or Type 8792/8793 to the lower chamber of the
actuator using a hose.
→ Attach the exhaust airline or a silencer to the upper chamber.
Control function B (single-acting actuator):
→ Connect the working connection A1 or A2
4)
of the position con-
troller Type 8791 or Type 8792/8793 to the upper chamber of the
actuator using a hose.
→ Attach the exhaust airline or a silencer to the lower chamber.
Control function I (double-acting actuators):
→ Connect working connections A1 and A2 to the respective
chambers of the actuator.
4) in line with desired safety position (see operating instructions
Type 8791 or Type 8792/8793)
English
Type 8798