Mid-West Instrument 142 User manual

Mid-West
®
Instrument
Installation and Operating Instructions
-
Model
1
42
B
ulletin No: IM
1
42
/
18
Supersedes IM142/02
6 5 0 0 d o b r y
d r s t e r l i n g h e i g h t s , m i 4 8 3 1 4
Wednesday, October 24, 2018
1. Safety
Before installing verify compatibility to the process
media and temperature in contact with the wetted
parts. Incompatible media and / or operation at
temperature extremes can cause premature
degradation of materials which could result in
safety risk to personnel.
Verify the selected pressure range (differential
pressure and working pressure) and the switch
ratings are within specification for your application.
arning! Remaining media may result in a
risk to personnel, environment etc.
Use sufficient precautionary
measures when removing and
transporting the product.
1.1 Intended use: The indicating / non-indicating
differential pressure s itches are used for
monitoring differential pressures in industrial
applications. The manufacturer shall not be liable for
any claims if the product is used in applications
contrary to the intended use.
1.2 Personnel: Personnel installing and putting this
instrumentation into service shall be suitably trained
and qualified in accordance ith local codes,
practices and regulations.
PRODUCT DESCRIPTION
The Model 142 “Delta Meter”® is a differential pressure
instrument available as a s itch, gauge, or both. A
flexible elastomer diaphragm and calibrated range spring
are moved by differential pressure. A magnet, coupled
ith the diaphragm, transmits motion through the all
of the pressure housing to a follo er magnet attached to
an indicating pointer. The rotation of the follo er
magnet causes the pointer to track movement of internal
driver magnet and indicate differential on the dial scale.
When equipped ith s itches, a contact is made or
broken by the magnetic field of the internal magnet. See
Bulletin ELECIM_142 Series/latest for gauges ith
s itches.
The diaphragm is totally supported upon reaching full
travel in either direction, providing full over-range
protection to rated orking pressure.
INSPECTION
Before installation check the product label on each
instrument against the receiving paper ork and the
intended application for correct part number, materials
of construction, orking pressure, dial range, etc. If
equipped ith s itches, check electrical rating, type of
enclosure, etc. Inspect for shipping damage and, if
damaged, report it immediately.
NOTE - Before attem ting re airs contact your local
Mid-West Re resentative or our factory. Failure to do
so will void any warranty.
DRIVER
MAGNET
FOLLOWER
MAGNET
DIAPHRAGM RANGE
SPRING
HIGH LOW

Installation and Operating Instructions
-
Model
1
42
INSTALLATION
Model 142 is calibrated and tested prior to shipment and
is ready for immediate installation. Use of the follo ing
installation procedures should eliminate potential
damage and provide optimum trouble-free operation.
1. CONNECTIONS
¼” FNPT connections are provided as standard ho ever
check the paper ork for the connections ordered. There
are t o connections on the housing identified as “HI”
and “LO” for high and lo pressure. Be sure to plumb to
proper connections on your system. Improper
connection ill not damage instrument, but it ill not
function properly. Flexible tubing is recommended to
minimize effect of possible vibration.
2. INSTRUMENT LOCATION
It is recommended that installation is no closer than one
inch of a steel surface other ise accuracy ill be
affected. 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 fluid. If the process contains particulates, a
“pigtail” loop or drop leg (manometer “U-tube”
configuration) in the tubing ill minimize the possibility
of it migrating into the instrument.
NOTE – On liquid a lications, unequal liquid heads on
high or low side will result in an inaccurate differential
ressure indication.
3. PANEL MOUNTING
Refer to Model 140 and 142 panel cut outs.pdf for panel
mount diagrams, dimensions, and options.
4. PIPE MOUNTING
An optional pipe mounting kit is available for mounting
the gauge to a 2” vertical or horizontal pipe. Refer to
dra ing belo pipe mount diagrams and dimensions
TROUBLE SHOOTING
1. Gauge does not indicate differential
A. Check for proper hook up, high to “HI” and lo
to “LO”
B. Make certain block valves are open and, if using
a 3-valve manifold, that the equalizer (balance)
valve is closed.
C. If A & B check out correctly, loosen or
disconnect the 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 po er 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 an “RGA” (return goods
authorization) number to return the instrument
for repair or replacement.
2 INCH PIPE MOUNT FOR VERTICAL OR
HORIZONTAL PIPE)
BACK CONNECTED PROCESS
PORTS
2-1/2 in. DIAL
SHOWN
MODEL 142
3.85 (97.8) 2.80 (71.1)
MODEL NUMBER
DIMENSION P
Inch (mm)
MODEL 140
DIMENSION B
Inch (mm)
4.70 (119.4) 3.80 (96.5)