Series DA/DS Bourdon Tube Pressure Switch

Brand: Dwyer Instruments, LLC

Customers tell us that the Dwyer Series DA/DS Bourdon Tube Pressure Switches are the best pressure switches made.

The Mercoid DA/DS Series is one of the world's broadest lines of pressure switches.

The DA/DS Series has extremely high sensitivity and great repeatability. 

The DA Models are equipped with two external adjustments, one for setting high pressure operating point, the other for setting low pressure operating point. Deadband, the difference between high and low setpoints, is adjustable over the full-scale. 

The DS Models are equipped with a single external adjustment for setting operating point only.

For mercury-free switches, choose between the snap action switch or hermetically sealed snap action switch. Hermetically sealed mercury switch also available.
  • Visible calibrated dial provides an easy and fast check without having to open device causing dangerous conditions to operators
  • On/off indication (except hermetically sealed snap switch models) gives operator clear indication of state of switched equipment that could be located in another location
  • Adjustable or fixed deadband supports control applications by reducing equipment wear-out by unnecessary recycling
  • External switch set-point adjustment reduces set-up time
  • Pressure ranges of full vacuum to 8000 psig gives application designers the ability to specify standard equipment, simplifying install and training, and reducing servicing costs
  • UL listed, CSA approved, many models FM approved to support rigorous process applications and regulations
  • General purpose, weatherproof or explosion-proof enclosures for a variety of indoor or outdoor environments meeting the needs of multiple applications and uses


Adjustment Type

  • Thumbscrew

Approvals & Certifications

  • CE
  • CSA
  • FM
  • UL

Electrical Connectors

  • 1/2” Conduit
  • 3/4” NPT Female
  • Screw Terminal

Electrical Rating

  • Adjustable Deadband SPDT: 10 A at 120/240 Vac
  • Fixed Deadband 15 A at 120/240 Vac
  • Hermetically Sealed, Fixed Deadband SPDT: 5 A at 120/240 Vac Resistive
  • Hermetically Sealed, Fixed Deadband SPDT: 5 A at 30 Vdc

Environmental Protection

  • Explosion-proof
  • General-purpose
  • NEMA 7
  • NEMA 9
  • NEMA 9A
  • Weatherproof

NPT Connection

  • Explosion-proof: 1/4” NPT Female
  • Weatherproof: 1/2”Male NPT on Ranges 15S & 16S
  • Weatherproof: 1/4” NPT Male


  • ± 1 % of Full Operating Range
  • ± 1.5 % on DS-7300 Models

Sensor Orientation

  • Vertical

Set Point - Decreasing

  • bar: 0 to 552
  • Inches Hg: -30 to 0
  • kPa: 0 to 55,200
  • psi: 0 to 8,000

Set Point - Increasing

  • bar: 0 to 552
  • Inches Hg: -30 to 0
  • kPa: 0 to 55,200
  • psi: 0 to 8,000

Switch Type

  • SPDT (Mercury Switch, Snap Switch, SPDT Hermetically Sealed Snap Switch)
  • SPST Mercury Switch

System Pressure

  • bar: 550
  • kPa: 55,000
  • psig: up to 8,000 for Select Models

Temperature Range

  • 82° C to (180° F)

Wetted Materials

  • 316 Stainless Steel
  • 403 Stainless Steel
  • Brass

  • Compressors
  • Mechanical HVAC or Process Equipment
  • Pump Control
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