Setra System SRPM - Manual (Page 9)

9
3.2 PLUMBING (ATTACHING PRESSURE TUBING)
Warning: Always attach tubing to the SRPM header and then place
Header onto SRPM. This will prevent overpressure from crimped or
collapsed tubes.
Use the following procedure for all room types: positive, negative or
neutral:
Typically a Room Pressure Snubber (RPS) is installed in the monitored
room. Often stiff nylon ¼” tubing is used for running pressure signals
from the SRPM to the monitored spaces. To prevent buckling and
collapse of this stiff tubing inside the electrical box, use the supplied soft
silicone tubing and tubing adaptors to transition from the fi eld tubing to
the pressure fi ttings on the SRPM.
Attach pressure tubing as follows:
1. Connect the 1/4 inch O. D. tubing running from the RPS (or
other pressure connection from the monitored space) to the 4½ x 4½
electrical box for the SRPM. Install one of the supplied 1/4 inch male
to male barbed tube adaptors onto the end of the tube then push the
4” length silicone tube (supplied) onto the other end. Thread the tubes,
with installed adaptor, through the conduit opening at the bottom of the
electrical box.
2. Next push the open end of the silicone tubing onto the SRPM
pressure tube header (H1) port labeled “+”. Note: The header is an
Electro-Pneumatic (EP) assembly. “+” indicates (Positive) pressure, and
“-” indicates negative or reference pressure.
3. For the most pressure stable operation, an RPS installed in the
reference pressure area is also recommended. In this case, install the
RPS in a hallway or reference space. Attach the tube to the SRPM in the
same way as for the + port, except attach the tube to the “-” port on the
pressure tube header. Tighten swivel fi ttings on the SRPM Header H1
assembly if they become loose, 9 in lb. max. Verify that the tubes are not
buckled, which could close off pressure signal at end of installation.
1/4” O.D.
Tubing
Electrical Box
Silicone
Tubing
RPS Tubing
SRPM
Header H1
RPS Room Pressure Snubber Plumbing inside Electrical Box