Magnehelic Gage Maintenance - Carrier AERO 39MN Installation, Start-Up And Service Instructions Manual

Fig. 128 — Puro-Frame Holding Frame and
Filter Retaining Clips
AIRFLOW
2" PRE-FILTER
Fig. 129 — Track for Draw-Thru Bag Cartridge
Filter Section
IN-TRACK BAFFLES — Filter sections are shipped with
adjustable in-track baffles. When installed properly as shown
in Fig. 130, the baffles close off empty space in the track pre-
venting air from bypassing the filters. Remove the baffles to
install filter elements, and replace the adjustable baffles after
the filters are in place. The adjustable baffles should be
spread far enough apart to ensure slight compression in the
foam gasket when closing the section door.
FLAT AND ANGLE FILTERS — Flat filter and angle filter
sections accommodate 2-in. or 4-in. thick filters. The section
as shipped accepts 2-in. filters. Remove angle spacer in each
track to provide the space required to accommodate 4-in. fil-
ters.
HEPA FILTERS — The Puro-Frame (available in sizes 03-61
only), HEPA holding frame will accommodate 12-in. deep
filters. HEPA filter sections used in blow-thru applications
are loaded from the front, through the access door or remov-
able panel. The HEPA filters are retained in the frame with
retaining brackets. RTV sealant should be used to seal be-
tween the filter frame and the filter media's neoprene gasket
to ensure a leaktight installation. Refer to Fig. 131 for details.
Downstream edge of frame to frame and frame to baffle shall
be sealed with RTV sealant.
Filter arrangements are shown in Fig. 132-136.
a39-2266
a39-2268
BAG
CARTRIDGE
Magnehelic Gage Maintenance —
7/8" HEADER
periodic servicing is required. Keep case exterior and cover
clean. Occasionally disconnect pressure lines to vent both
sides of gage to atmosphere and re-zero.
CALIBRATION CHECK — Select
a39-2267
manometer of known accuracy and in an appropriate range.
Using short lengths of rubber or vinyl tubing, connect the
high pressure side of the Magnehelic gage and the test gage
to two legs of a tee. Very slowly apply pressure through the
third leg. Allow a few seconds for pressure to equalize, fluid
to drain, etc., and compare readings. If accuracy is unaccept-
able, the gage may be returned to factory for recalibration.
For best results, return gage to the factory. Ship prepaid to:
Dwyer Instruments, Inc.
Attn: Repair Dept.
102 Indiana Highway 212
Michigan City, IN 46360
To calibrate in the field, use the following procedure:
Calibration:
137
3/4" x 3/4"
FOAM GASKET
FILTER
FILTER
Fig. 130 — In-Track Baffle for Flat, Angle and
Sideloading Bag/Cartridge Filter Sections
IMPORTANT: If bezel binds when installing, lubricate
threads sparingly with light oil or molybdenum disulphide
compound.
CAUTION
Attempted field repair may void your warranty. Recalibra-
tion or repair by the user is not recommended.
1. With gage case, held firmly, loosen bezel, by turning
counterclockwise. To avoid damage, canvas strap
wrench or similar tool should be used.
2. Lift out plastic cover and "O" ring.
3. Remove scale screws and scale assembly. Be careful not
to damage pointer.
ADJUSTABLE IN-TRACK
BAFFLE
No lubrication or
a second gage or