APTech AZ4657 - Manual (Page 3)

Operation Manual Manual Diaphragm Valves
Manual 15000004 Revision 7 Page 3 of 4
E. Operation
1. Perform the following to close the valve.
a. Rotate the valve handle clockwise as viewed from the top until a sudden, large increase in
torque indicates that the internal hard stop in the actuator or in the valve body is reached.
Caution: Torque to operate a valve may noticeably increase as the valve is closed due to
load from the internal pressure. Higher internal pressure will require higher operation
torque. Do not mistake an actuation torque increase due to the internal pressure with that
due to contacting the valve internal stop. This could result in the valve being left in the
open position when the intention was to close the valve.
b. For valves with OPEN/CLOSED status indication, verify that handle indicator shows the
valve is in the CLOSED position.
c. For AP3157, AK/AP/AZ3657, and AK/AP/AZ4657 valves, turn the handle fully
clockwise until the handle drops down. AP3157, AK/AP/AZ3657, and AK/AP/AZ4657
valves have a small detent in the open position, which requires a slightly higher torque at
the initial portion of the valve travel to exit the detent.
d. For AP3900 valves, turn the handle fully clockwise until the handle drops all the way
down. The top edge of the flange on the lock stem (the part at the center of the handle)
should be flush with the top surface of the handle when the valve is in the closed position.
e. If an ISH switch option was installed, verify that the output signal changed states.
2. Perform the following to open the valve.
a. Rotate the valve handle counterclockwise until an increase in torque indicates that the
internal stop in the actuator is reached.
b. For AP3157, AK/AP/AZ3657, AK/AP/AZ4657, and AP3900 valves, pull the handle up
and turn counterclockwise to open the valve. This feature prevents the valve from being
accidentally opened.
c. For valves with OPEN/CLOSED status indication, verify that handle rotation has reached
the OPEN indication. On AP3800 and AP3900 valves, only solid dots of increasing size
will be visible through the handle window when the valve is fully open.
d. If an ISH switch option was installed, verify that the output signal changed states.
Caution: Do not use a tool to apply excessive opening or closing torque to the valve handle as
damage may result.
3. When a valve is in the closed position, the inlet ports are isolated from the outlet ports. When
a valve is in the open position, all ports are common.