Pressure Systems, Inc. Model 9116 User’s Manual
Page 113
www.PressureSystems.com
5.1.6.2
Tubing Plate O-Ring Replacement
The following is a step-by-step procedure to replace Tubing Plate O-rings in a
Model 9116
Intelligent Pressure Scanner.
(1) Disassemble the module as described in
Section 5.1.2
.
(2) Place the scanner with the tubing plate on a clean, lint free surface.
(3) Hold the top plate/calibration valve assembly with one hand, supporting the bottom
assembly to prevent dropping when all screws are removed. Remove the six (6) Allen-
head screws on the top plate that secure the valve assembly to the top plate.
(4) Carefully rotate or slide the tubing plate back and forth, pivoting on the guiding pin about
1/8" several times. This is done to loosen the O-rings from the calibration manifold. Lift the
tubing plate straight up. Do not touch the calibration manifold.
(5) Inspect for the presence of shim washers around each of the six (6) screws. If washers are
present, retain for use during reassembly.
(6) Remove and replace the O-rings needing maintenance, using the procedure described in
Section
5.1.6.1
. Note that the O-ring seals use an additional Teflon cup seal placed on top
of the O-ring. These seals should be replaced as necessary. Note that these Teflon seals
do
not
require the use of Krytox
®
grease.
(7) Examine the tubing plate and calibration manifold to verify that no contaminants are on
either surface. This generally requires microscopic examination. Replace the tubing plate
by slowly placing the plate on the calibration manifold. Make sure that the O-ring/cup seal
side is down toward the pneumatic sliding manifold and the guiding pin on the calibration
valve housing fits into the mating hole of the tubing plate. Also, ensure that shim washers,
if used, are installed between the tubing plate and the calibration manifold assembly, in all
six (6) locations.
(8) Replace the six (6) Allen-head screws that pass through the top plate to secure the
calibration valve assembly. Tighten evenly, making sure that the screws are only finger
tight plus 1/8 turn. It is important not to over tighten the screws since the pneumatic seal is
made using dynamic O-rings.
(9) Reassemble the module.
(10) Test your scanner to ensure proper operation.
