Midwest Delta Meter 142 User manual

BULLETIN NO. IM142/09
Instrument
Mid-West®
INSPECTION
Before installation check the nameplate on each
instrument against the receiving paperwork and the
intended application for correct part number, materials
of construction, working pressure, dial range, etc. If
equipped with switches, check electrical rating. Inspect
for shipping damage and, if damaged, report it
immediately.
NOTE - Before attempting repairs contact your
local Mid-West Representative or our factory.
Failure to do so will void any warranty.
PRODUCT DESCRIPTION
The Model 142 "Delta Meter"®is a medium range
differential pressure instrument available as a switch, a
gauge, or both. See the “Part Numbering System”,
(Fig. TBD) for available options.
A flexible elastomer diaphragm and calibrated range
spring are moved by differential pressure. A pair of
magnets, coupled with the diaphragm, transmit this
motion through the wall of the pressure housing to a
follower magnet attached to an indicating pointer. The
rotation of the follower magnet causes the pointer to
track the movement of the internal magnet and indicate
the differential on the dial scale.
INSTALLATION
The model 142 is calibrated and tested prior to
shipment and is ready for immediate installation. Use
of the following installation procedures should eliminate
potential damage and provide optimum trouble-free
operation.
1. PROCESS CONNECTIONS
1/4" FNPT are provided as standard however check
the paperwork for the connections ordered. There are
two connections on the housing identified as "hi" and
"lo" for high pressure and low pressure. Be sure these
get plumbed to the proper connections on your
system. Improper connection will not damage the
instrument, but it will not function properly. Flexible
tubing is recommended to minimize effect of possible
vibration.
2. INSTRUMENT LOCATION
On liquid service the instrument should be mounted
below the process connections to facilitate self-
bleeding. On gas service it should be located above
the process connections to promote self-draining. If
the process contains particulates, a "pigtail" loop or
drop leg (manometer "U-tube" configuration) in the
tubing will minimize the possibility of it migrating into
the instrument.
3. PANEL MOUNTING
Gauges with 2-½" dials can only be mounted through
the rear of the panel. Make the proper panel cutout as
indicated in (Fig .TBD). Remove the (4) bezel screws.
Insert the gauge front through the rear of the panel and
reinstall the bezel screws through the front of the panel
and into the gauge bezel. Tighten the screws securely,
alternating in a diagonal pattern.
Gauges with a 3 1/2 “ dial must be mounted from the
front of the panel. Contact the factory for mounting
information and dimensional data.
MODEL 142: “DELTA METER®”
Installation and O
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Instructions

Gauges with 4-½" dial should be mounted from the
front of the panel. Make the cutout as indicated in
(Fig. TBD). Insert the (4) panel mounting studs, finger
tight, into the metal inserts located in the rear of the
bezel. Insert the gauge through the panel, aligning the
panel mounting studs with the holes in the panel.
Install the (4) #8-32 nuts onto the studs and tighten
securely.
4. PIPE MOUNTING
An optional pipe mounting kit is available for mounting
the gauge to a 2” vertical or horizontal pipe.
DIMENSIONAL INFORMATION
TROUBLESHOOTING
1. Gauge does not indicate differential.
A. Check for proper hook up, high to "hi" low to "lo".
B. Make certain block valves are open and that the
equalizer (balance) valve is closed (if using a 3
valve manifold.
C. If A & B check out correctly, loosen high-
pressure line to determine if there is pressure to
the instrument.
D. Verify gauge is not in an electromagnetic /
magnetic environment. i.e.; close proximity to
high current power lines.
E. If there is pressure to the instrument, check to
determine that there is differential across the unit
being monitored. If so, contact the factory for
assistance and/or and “RGA” (Return Goods
Authorization) number to return the instrument
for repair or replacement.

Part Numbering System
1 BASIC MODEL NUMBER
2 BODY MATERIAL
A. Aluminum (3000 PSIG)
B. Brass (1500 PSIG)
S. 316 / 316L S.S. (3000 PSIG)
3 DIAL SIZE
A. 2-1/2" Round Uni-Directional Dial
C. 4-1/2” Round Uni-Directional Dial
E. 3 1/2” Round Uni-Directional Anod. Alum. Hous. Assy.
G. 4-1/2” Round Uni-Directional Anod. Alum. Hous. Assy.
T. Non-indicating Differential Pressure Switch Only
(Select Appropriate Electrical Options)
Z. Special
4 SEALS & DIAPHRAGM
0. Buna N
1. * Viton®
5. Ethylene Propylene
9. Special (Uncoded Options)
5 CONNECTIONS
0. 1/4" FNPT Back Connections
2. Dual1/4" FNPT Top & Bottom Connections (non electrical option
units only)
3. 1/4" FNPT Bottom Connections
4. 7/16”-20 Str. Thd. O-Ring (back Connections)
5. 1/2” FNPT S.S. Adaptors
8. 1/4" FNPT End Connections
9. Special (Uncoded Options)
(1)1375 PSIG SWP
(2)Complete assembly 3rd party Certified, Class I, Division 2,
Groups A, B, C & D; Class II, Division 2, Groups F & G
NOTE: Not all options are available in combination with other
options.
Mid-West®
Instrument
6500 Dobry Dr. Sterling Heights, MI 48314
TEL: [phone] FAX: [phone]
E-Mail:[email protected]m
Web Page: www.midwestinstrument.com
6 OPTIONS (Up to four options)
O. None
A. Reversed High/Low Process Connections
F. Pipe Mounting Kit (Not available with both Reversed Port & all
Electrical options)
L. Liquid Fill ( Not available w/follower pointer Option M or 3 ½” Dial)
M. Maximum Indicator Follower Pointer
T. Oxygen Cleaning
U. S.S. Tag w/S.S. Wire
V. S.S. Tag w/S.S. Screws (contact factory on switch options)
W. Wall Mounting Kit (Not available with Back Connections)
X. Chemical Seals (Contact Factory For Accuracy)
Z. Special Uncoded Options
7 ELECTRICAL CONFIGURATIONS
(Switch Adjustable Range 15-95%)
O. None
A. One (1) Reed Switch in NEMA 4X / IP66 Enclosure
B. Two (2) Switches in NEMA 4X / IP66 Enclosure
E. One (1) Reed Switch in NEMA 4X / IP66 Aluminum Enclosure
With CSA / UL Div II Listing. (1) (2)
F. Two (2) Reed Switches in NEMA 4X / IP66 Aluminum Enclosure
With CSA / UL Div II Listing. (1) (2)
T. 4-20 mA Transmitter in NEMA 4X/IP66
W. 4-20 mA Transmitter in NEMA 4X/IP66 aluminum enclosure,
Division 2 Hazardous Locations. (1) (2)
Z. Special
8 ELECTRICAL SPECIFICATIONS
A. SPDT 3W, 0.25 Amp, 125 VAC/VDC
B. SPST 25W, 0.5 Amp, 240 VAC/VDC Normally Open
T. 4-20 mA Transmitter (Loop Powered 8-28 VDC Input)
Z. Special
* Viton is a registered trademark of Dupont Dow Elastomers
1 4 2
PROOF PRESSURE: Two times the working pressure or 6000 PSI, whichever is lower at ambient temperature.
TEMPERATURE LIMITS: -40 ˚F (-40˚C) to 200˚F (93˚C). These limits are based on the entire instrument being saturated to
these temperatures. System (process) temperatures may exceed these limitations with proper installation. Contact our customer
service representative for details.
STANDARDS: All Model 142 Series differential pressure gauges either conform to and/or are designed to the requirements of
the following standards:
ASME B1.20.1 NACE MR0175
ASME B40.100 NEMA Sts. 250
EN-61010-1 UL Std. No. 50 & 508 CSA-C22.2 No. 14,& 25
CE Marking Statements:
This product shall not be placed in an Explosive atmosphere as defined by the ATEX Directive 94/9/EC Evaluation to the directive’s
requirements is in process.
The Pressure Equipment Directive has been determined to be non applicable for CE marking. These products are manufactured in
accordance with article 3, paragraph 3 of the directive, “sound engineering practice”. They fall below category I for non-hazardous gases,
hazardous liquids, & non-hazardous liquids. This product also falls below category I for hazardous gases at or below 200 bar.