5.
If replacing a PTFE diaphragm, re-invert the diaphragm.
6.
If the actuator mode of operation is fail open or fail close, select one of these steps.
If the actuator
mode of opera-
tion is ...
Then ...
Fail open
Reduce the air pressure until the back of the diaphragm is flat against the bonnet.
Fail close
1.
Connect the air line to the bonnet’s cylinder.
2.
Load the chamber with sufficient air to move the diaphragm upward until
the back of diaphragm is flat against the bonnet. Do not apply excessive
air pressure that results in inversion of the diaphragm.
7.
For more information, see
3.3 Tighten the bonnet fasteners on page 7
.
8.
If the actuator mode of operation is fail open, then release the air, allowing the valve to open.
3.6 Adjust the travel (closing) stop
The travel stop is designed to prevent overloading of the diaphragm, thus prolonging diaphragm life.
Travel stops are factory set and do not require routine adjustment. However, travel stop adjustment is
recommended when replacing a valve diaphragm.
A travel stop is optional on series 3, 5, 8, and 16 actuators.
1.
Release the air pressure in the actuator covers.
2.
Loosen the jam nuts and back off one turn.
3.
If the actuator is a double acting or fail open actuator, then apply enough pressure in the upper cov-
er to close the valve.
4.
For all modes of operation, turn the lower nut clockwise while preventing the adjusting bushing from
rotating until the valve begins to leak.
3.6 Adjust the travel (closing) stop
10
Advantage® 2.1 Actuator Maintenance Manual
