PP904A AND B DIFFERENTIAL PRESSURE REGULATORS
C
A
STATIC
DIRECT ACTING SHOWN
HEAD
M18382
AIR FLOW
Fig. 6. Static pressure sensing.
CALIBRATION
See Pneumatic Airflow Control System 77-5031 for calibration
using the Airflow Test Panel or use the following procedure:
1.
To set the throttling range, loosen the throttling range
adjustment knob (TR) and slide the pointer to the
desired setting. See Fig. 3.
2.
Tighten the knob.
3.
Turn the coarse setpoint adjustment knob to position the
pointer to the desired setting on the setpoint scale.
4.
Connect a Magnehelic Gage between the A and C con-
nections, if not part of the system. If desired, a 0 to 30
psi gage can be teed into the PP904A branch line to
read the branch line pressure.
5.
With the system running and the PP904 in control, turn
the fine setpoint adjustment knob until the desired read-
ing is shown on the Magnehelic Gage.
NOTE:
Repeat Steps 2, 3 and 4 if the throttling range is
changed.
3
95-5519EF
