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Mercoid Series DA / DS

Bourdon Tube Pressure Switch — Pressure Ranges to 8000 psig

Mercoid Series DA Pressure Switch

Series DA/DS Bourdon Tube Pressure Switch

Customers tell us this is the best pressure switch made. The Mercoid Series DA/DS is one of the world's broadest lines of pressure switches — whatever your application, it can most likely be fully satisfied with a D Series switch.

The D Series has extremely high sensitivity and great repeatability. Series DA models feature two external adjustments — one for the high pressure operating point, one for the low — with deadband adjustable over the full scale. Series DS models have a single external adjustment with factory-fixed deadband.

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Series DA Features

  • Visible calibrated dial
  • On/off indication (except hermetically sealed snap switch models)
  • Adjustable or fixed deadband
  • SPDT snap-action, hermetically sealed snap action or hermetically sealed mercury switch
  • External switch setpoint adjustments
  • Minimum deadband obtainable at any point in the range
  • Pressure ranges from full vacuum to 8000 psig
  • UL listed, CSA approved — many models FM approved
  • General purpose, weatherproof, or explosion-proof enclosures

Specifications

Wetted MaterialsBrass, 403 SS, or 316 SS
Temperature Limit180°F (82°C)
Pressure LimitMaximum pressure of the operating range
Enclosure OptionsGeneral purpose, weatherproof, or explosion-proof
Repeatability±1% of full operating range; ±1.5% on DS-7300 models
Switch TypeSPST mercury, SPDT mercury, SPDT snap, or SPDT hermetically sealed snap switch. Other circuit types available.
Electrical ConnectionsScrew terminal
Conduit ConnectionGeneral purpose: ½" hole for conduit hub. Weatherproof: ½" conduit hub. Explosion-proof: ¾" female NPT.
Process ConnectionGeneral purpose / weatherproof: ¼" male NPT (½" male NPT on range 15S and 16S). Explosion-proof: ½" male NPT and ¼" female NPT.
Mounting OrientationVertical
Set Point AdjustmentThumbscrew
WeightGeneral purpose: 4 lb (1.8 kg). Weatherproof: 6 lb (2.7 kg). Explosion-proof: 8 lb (3.5 kg).
Agency ApprovalsCE, CSA, FM, UL (mercury switch units are not CE approved; consult factory for FM approval models)

Series DA Options & Ordering

Mercoid Series DAH Explosion-Proof Enclosure

Explosion-Proof Enclosure (Series DAH)

Suitable for Class I, Groups C and D; NEMA 7; Class II, Groups E, F, G; Class III NEMA 9 and 9A, Division 1. Add "H" to model number after DA or DS. Example: DAH-31-153-7

Weatherproof Enclosure (Series DAW)

Add "W" to model number after DA or DS and change 1 to 3. Example: DAW-33-153-7

FM Approved

For general purpose and explosion-proof models. Add "F" to model number after DA, DS, DAH, or DSH. Examples: DAF-31-153-7 or DAHF-31-153-7

Other Options (Consult Factory)

DPDT switches, fixed deadband mercury switch units, manual reset, two-stage operation, acetal bushed movement (high vibration/pulsation), fungus proofing, siphon, diaphragm seals, mounting flange, and remote connection.

How To Order

Operating Requirements

A general purpose NEMA 1 enclosure is standard on all Series D switches. Weatherproof and explosion-proof housings are optional — add a third character to the model number (e.g., DAW = DA with weatherproof enclosure).

Wetted Material

Bourdon tubes are available in brass, Type 403 SS, and Type 316 SS. Material is part of the series type number: 3 = brass, 2 = 403 SS, 4 = 316 SS. Example: DA-31, DA-7031, DS-7231, and DA-531 all have brass tubes.

Switch Type and Action

Snap-action switch models always start with series type number 7 (e.g., DA-7031, DS-7231). Mercury switch models do not (e.g., DA-31-153). Snap switches are available in SPDT and DPDT; mercury switches in SPST, SPDT, DPDT, and DPST.

Operating Range

The last part of the model number is the range number. Operation is adjustable within the shown range limits. The upper limit is also the maximum pressure — do not exceed. Example: DAW-33-3-2 has range 2 = 0 to 30" Hg vacuum.

Available Series D Models

SPDT Mercury Switch

4A @ 120V, 2A @ 240V

ModelRangeDeadbandTube
DA-21-153-5S2–60 psigAdjust. 4 psig min403SS
DA-21-153-6S5–100 psigAdjust. 6 psig min403SS
DA-21-153-8S10–200 psigAdjust. 8 psig min403SS
DA-21-153-9S10–300 psigAdjust. 10 psig min403SS
DA-21-153-10S25–600 psigAdjust. 25 psig min403SS
DA-21-153-11S50–1000 psigAdjust. 60 psig min403SS
DA-21-153-12S100–1500 psigAdjust. 90 psig min403SS
DA-21-153-13S300–2500 psigAdjust. 150 psig min403SS
DA-21-153-15S500–5000 psigAdjust. 450 psig min403SS
DA-21-153-16S800–8000 psigAdjust. 750 psig min403SS

SPST Normally Closed Mercury Switch

10A @ 120V, 5A @ 240V — Opens on increase

ModelRangeDeadbandTube
DA-21-2-5S2–60 psig4 psig min, Adjust403SS
DA-21-2-6S5–100 psig6 psig min, Adjust403SS
DA-21-2-8S10–200 psig8 psig min, Adjust403SS
DA-21-2-9S10–300 psig10 psig min, Adjust403SS
DA-21-2-10S25–600 psig25 psig min, Adjust403SS
DA-21-2-11S50–1000 psig60 psig min, Adjust403SS
DA-21-2-12S100–1500 psig90 psig min, Adjust403SS
DA-21-2-13S300–2500 psig150 psig min, Adjust403SS
DA-21-2-15S500–5000 psig450 psig min, Adjust403SS
DA-21-2-25S30" Hg Vac–60 psig6 psig min, Adjust403SS

SPST Normally Open Mercury Switch

10A @ 120V, 5A @ 240V — Closes on increase

ModelRangeDeadbandTube
DA-21-3-5S2–60 psig4 psig min, Adjust403SS
DA-21-3-6S5–100 psig6 psig min, Adjust403SS
DA-21-3-8S10–200 psig8 psig min, Adjust403SS
DA-21-3-9S10–300 psig10 psig min, Adjust403SS
DA-21-3-10S25–600 psig25 psig min, Adjust403SS
DA-21-3-11S50–1000 psig60 psig min, Adjust403SS
DA-21-3-12S100–1500 psig90 psig min, Adjust403SS
DA-21-3-13S300–2500 psig150 psig min, Adjust403SS
DA-21-3-15S500–5000 psig450 psig min, Adjust403SS
DA-21-3-25S30" Hg Vac–60 psig6 psig min, Adjust403SS

SPDT Snap Switch — Adjustable Deadband

Series DA — dual external adjustments

ModelRangeDeadbandTube
DA-7021-153-5S2–60 psig13.5 psig min, Adjust403SS
DA-7021-153-6S5–100 psig19.5 psig min, Adjust403SS
DA-7021-153-8S10–200 psig30 psig min, Adjust403SS
DA-7021-153-9S10–300 psig45 psig min, Adjust403SS
DA-7021-153-10S25–600 psig67.5 psig min, Adjust403SS
DA-7021-153-11S50–1000 psig142.5 psig min, Adjust403SS
DA-7021-153-12S100–1500 psig195 psig min, Adjust403SS
DA-7021-153-13S300–2500 psig390 psig min, Adjust403SS
DA-7021-153-15S500–5000 psig1350 psig min, Adjust403SS
DA-7021-153-16S800–8000 psig2250 psig min, Adjust403SS

SPDT Snap Switch — Fixed Deadband

Series DS — single external adjustment, factory-set deadband

ModelRangeDeadbandTube
DS-7231-153-11/8–15 psig1.5 psig fixedBrass
DS-7231-153-20–30" Hg Vac3" Hg fixedBrass
DS-7231-153-310" Hg Vac–12 psig1.5 psig fixedBrass
DS-7231-153-3A1/8–20 psig1.5 psig fixedBrass
DS-7231-153-41–35 psig1.5 psig fixedBrass
DS-7231-153-52–60 psig2 psig fixedBrass
DS-7231-153-65–100 psig2.5 psig fixedBrass
DS-7231-153-75–150 psig3 psig fixedBrass
DS-7231-153-810–200 psig4 psig fixedBrass
DS-7231-153-910–300 psig5 psig fixedBrass

SPDT Hermetically Sealed Snap Switch

Series DS — fixed deadband, hermetically sealed

ModelRangeDeadbandTube
DS-7331-153-11/8–15 psig3 psig fixedBrass
DS-7331-153-20–30" Hg Vac5" Hg fixedBrass
DS-7331-153-52–60 psig3 psig fixedBrass
DS-7331-153-65–100 psig3.75 psig fixedBrass
DS-7331-153-75–150 psig5.25 psig fixedBrass
DS-7331-153-810–200 psig6.75 psig fixedBrass
DS-7331-153-910–300 psig9 psig fixedBrass

Additional models and custom configurations available. Contact us for 316 SS tube variants, DPDT circuits, and special options.

Series D Enclosures

General Purpose, Watertight, and Explosion-Proof enclosure options with NEMA ratings and weights.

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Operating Options

Type DA, DS, DR, and DL operating modes — adjustable or fixed deadband, manual reset.

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Switch Circuits & Ratings

Switch circuit suffix codes and full electrical ratings for snap and mercury switch contacts.

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Contact Us

Tel: 1+201.419.6120

[email protected]

9:00am – 4:30pm EST
Monday – Friday

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Series DA Sub-Pages

Related Products

Downloads

Series DA/DS Datasheet (PDF)