Install Instructions

Mercoid
®
Series “D” Pressure Controls feature hermetically
sealed mercury switches, Bourdon tube power elements, visible
setpoint, adjustable deadband or fixed deadband and pressure
ranges from 0-30” Hg. Vac to 800-8000 psig (345 bar).
FEATURES
• Visible calibrated dial
• On/off indication
• Adjustable, fixed deadband, or manual reset
• External switch setpoint adjustments
• Minimum deadband is obtainable at any point in the range
• Pressure Ranges of full vacuum to 8000 psig.
• UL listed, CSA approved. Many models FM approved.
• General purpose, weatherproof or explosion-proof
enclosures
• Single or two stage operation
SPECIFICATIONS
Wetted Materials: Brass, 403 SS, or 316 SS.
Temperature Limit: 180°F (82°C).
Pressure Limit: Maximum pressure of the operating range.
Enclosure Rating: General purpose, weatherproof or explosion-
proof.
Repeatability: ±1% of full operating range.
Switch Type: See circuit chart.
Electrical Rating: See electrical ratings chart.
Electrical Connections: Screw terminal.
Conduit Connection: General purpose: 1/2˝ hole for conduit
hub. Weatherproof: 1/2˝ conduit hub. Explosion-proof: 3/4˝ female
NPT.
Process Connection: General purpose and weatherproof: 1/4˝
male NPT, 1/2˝ male NPT on ranges 15S and 16S. Explosion-
proof: 1/2˝ male NPT and 1/4˝ female NPT.
Mounting Orientation: Vertical.
Set Point Adjustment: Thumbscrew.
Weight: General Purpose: 4 lb (1.8 kg), weatherproof: 6 lb
(2.7kg), explosion-proof: 8 lb (3.5 kg).
Deadband: See Ranges and Differentials Chart.
INSTALLATION
Location and Mounting
Select a location that is recommended by equipment manufacter
and reasonably free from vibration caused by reciprocating or
rotating machinery. Where excessive vibration occurs, use a
remote connection and mount by means of a mounting bracket or
separable flange (available on order). When in doubt about exces-
sive vibration, use a remote connection. Where pulsations, pres-
sure surges, or water hammer are present, protect the control with
a surge tank or scrubber. Mount all controls vertically and
level.
General Purpose Controls: Install controls prefixed by the let-
ters DA, DAF, DRF, DL, DS, DSF, firmly in a level position. Do not
mount the control by twisting the case; use a wrench on the
square part of the 1/4″ bottom pipe connection. To level, sight
across the two cover screws or check the lower end of the glass
opening in the cover to see that the control is lined up horizontal-
ly. On general purpose controls provided with a flange, mount by
means of the three holes in the flange.
Series “D” Pressure Controls with Mercury Switches
Specifications - Installation and Operating Instructions
Bulletin IN-0118
1/4 N.P.T.
6-1/64
[152.8]
DIA.
7/8 [22.23]
ADJUSTMENT SCREWS
2-1/4
[57.15]
1-5/8
[41.28]
1/2 [12.7]
CONDUIT HOLE
5/8 [15.88]
MERCOID
CONTROL
MERCOID DIVISION
DWYER INSTRUMENTS, INC.
P.O. BOX 258 • MICHIGAN CITY, INDIANA 46361 U.S.A.
Phone: [phone] www.dwyer-inst.com
Fax: [phone] e-mail: [e-mail]
Remote Connection
No. 49-62 (300 psi)
No. 49-62HP (to 2500 psi)
Mounting Bracket
No. 33-25
Pigtail Siphon
No. 42-52 (300 psi)
No. 42-58 (2,000 psi)
ACCESSORIES
6-1/2⬙ DIA.
13/64⬙
DIA.
BACK
CONNECTION
BOTTOM CONNECTION
DA-24
DA-34
DA-44
DA-23
DA-33
DA-43
HOLES FOR
FLANGE SCREWS
1/2⬙ CONDUIT
CONNECTION
5-3/4⬙ DIA.
1/4⬙ NPT
1-1/2⬙
1/4⬙ NPT
1-1/8⬙
DA-21
DA-31
DA-41
DA-22
DA-32
DA-42
General Purpose with
Flange for Surface Mounting
General Purpose
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