Dwyer Instruments Magnehelic 2000 Series Operating Instructions Manual

BULLETIN NO.A-27

Magnehelic® Differential Pressure Gage

OPERATING INSTRUCTIONS

SPECIFICATIONS

Dimensions: 4-3/4 dia. x 2-3/16 deep.
Weight: 1 lb. 2 oz.
Finished: Baked dark gray enamel.
Connections: 1/8 NPThigh and low pressure

taps, duplicated, one pair side and one
pair back.

Accuracy: Plus or minus 2% of full scale, at

70°F. (Model 2000-0, 3%; 2000-00, 4%).

Pressure Rating: 15 PSI (0,35 bar)
Ambient Temperature Range: 20° to 140°F

(-7 to 60°C).

Standard gage accessories include two 1/8

NPT plugs for duplicate pressure taps,
two 1/8 NPTpipe thread to rubber tubing
adapters, and three flush mounting
adapters with screws.

Caution: For use with air or compatible

gases only.

For repeated over-ranging or high cycle rates,

contact factory.

Not for use with Hydrogen gas. Dangerous

reactions will occur.

DWYER INSTRUMENTS, INC.

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361 U.S.A.

Phone: [phone] www.dwyer-inst.com
Fax: [phone] e-mail: [e-mail]
Lit-by-Fax: [phone]

11/16

[17.46]

1/8 NPT LOW

PRESSURE

7/16

[11.11]

1-11/16

[42.86]

1/2

[12.70]

1/8 NPT LOW

PRESSURE

1/8 NPT HIGH

PRESSURE

1/2

[12.70]

1/8 NPT HIGH

PRESSURE

Ø4-1/8 [104.78] BOLT

CIRCLE FOR PANEL MOUNTING

120° APART

1-1/4

[31.75]

Ø4-3/4

[120.65]

1-3/4

[44.45]

1.Select a location free from excessive vi-

bration and where the ambient temperature
will not exceed 140°F. Also, avoid direct
sunlight which accelerates discoloration of
the clear plastic cover. Sensing lines my be
run any necessary distance. Long tubing
lengths will not affect accuracy but will in­crease response time slightly. Do not re­strict lines. If pulsating pressures or vibra­tion cause excessive pointer oscillation,
consult the factory for ways to provide ad­ditional damping.

2. All standard Magnehelic gages are cali-

brated with the diaphragm vertical and
should be used in that position for maxi­mum accuracy. If gages are to be used in
other than vertical position, this should be
specified on the order. Many higher range
gages will perform within tolerance in other
positions with only rezeroing. Low range
Model 2000-00 and metric equivalents
must be used in the vertical position only.

3. Surface Mounting

Locate mounting holes, 120° apart on a 4­1/8

⬙ dia. circle. Use No. 6-32 machine

screws of appropriate length.

4. Flush Mounting

Provide a 4-9/16⬙ dia. opening in panel.
Insert gage and secure in place with No. 6­32 machine screws of appropriate length,
with adapters, firmly secured in place. To
mount gage on 1-1/4

⬙-2⬙ pipe, order op-

tional A-610 pipe mounting kit.

MAGNEHELIC®INSTALLATION

5. To zero the gage after
installation

Set the indicating pointer exactly on the
zero mark, using the external zero adjust
screw on the cover at the bottom. Note that
the zero check or adjustment can only be
made with the high and low pressure taps
both open to atmosphere.

Operation

Positive Pressure:Connect tubing from
source of pressure to either of the two high
pressure ports. Plug the port not used. Vent
one or both low pressure ports to atmos­phere.

Negative Pressure: Connect tubing from
source of vacuum or negative pressure to
either of the two low pressure ports. Plug
the port not used. Vent one or both high
pressure ports to atmosphere.

Differential Pressure: Connect tubing
from the greater of two pressure sources to
either high pressure port and the lower to
either low pressure port. Plug both unused
ports.

When one side of the gage is vented in
dirty, dusty atmosphere, we suggest an A­331 Filter Vent Plug be installed in the open
port to keep inside of gage clean.

A. For portable use of temporary installa­tion use 1/8

⬙ pipe thread to rubber tubing

adapter and connect to source of pressure
with rubber or Tygon tubing.

B. For permanent installation, 1/4

⬙ O.D., or

larger, copper or aluminum tubing is rec­ommended. See accessory bulletin S-101
for fittings.

Ordering Instructions:

When corresponding with the factory re­garding Magnehelic

®

gage problems, be
sure to include model number, pressure
range, and any special options. Field repair
is not recommended; contact the factory
for repair service.