PSW-12

Supported Applications

The Omega PSW-12 series consists of compact, vibration-resistant pressure switches designed for Class I Hazardous Locations. These explosion-proof units utilize a diaphragm sensor to detect pressure changes and actuate snap-action SPDT or DPDT switches. The series is certified for use in:

• Class I, Divisions 1 & 2, Groups A, B, C & D
• Class II, Divisions 1 & 2, Groups E, F & G
• Class III locations
• Non-hazardous locations

The switches feature an internal slotted adjustment screw for set point control and are suitable for rack mounting with accessible adjustments when installed.

Operating Conditions & Performance

The PSW-12 series operates within a broad ambient temperature range of -50 to 80°C (-58 to 176°F). Setpoint typically shifts less than 1% of the adjustable range for an ambient temperature change of 28°C (50°F). Process temperature limits depend on the diaphragm material selected:

• Polyimide Diaphragm: -28 to 93°C (-20 to 200°F)
• Stainless Steel Diaphragm: -17 to 160°C (0 to 320°F)

The series offers a measurement range from 8 to 6000 psi (0.6 to 414 bar) with setpoint repeatability of ±1% of the adjustable range. Mechanical contact life is rated at 10 million cycles. The switches maintain stability under shock and vibration, repeating setpoints after exposure to 75 g for a 10 ms duration or 15 g across 10 to 2000 Hz.

Pressure Ratings

Maximum working pressure varies by model range from 600 to 8000 psi (41 to 551 bar). Proof pressure limits, representing the maximum occasional pressure without permanent damage, range from 1000 to 10,000 psi (69 to 689 bar) depending on the specific model configuration.

Configuration Options

The PSW-12 series is configurable across diaphragm types, switch outputs, and pressure ranges. The housing is constructed from 300 stainless steel with an enclosure rating of NEMA 4X, 7, 9, and IP66.

Diaphragm & Wetted Materials

Selectable diaphragm options define the process temperature capability and media compatibility:

• PFA-coated Polyimide Diaphragm with Buna N O-ring (Model prefix T)
• FKM O-ring configuration (Model prefix V)

Switch Outputs & Electrical Ratings

The series offers Single or Dual SPDT switch configurations. Silver contacts are rated for 5 A @ 250 Vac, and 5 A resistive / 3 A inductive @ 28 Vdc. The electrical connection is provided via a ½ MNPT conduit with factory-sealed lead wires measuring 1.8 m (72").

Process Connection & Dimensions

The pressure connection is ¼ FNPT. Overall dimensions are approximately 31.8 mm (1.25 in) diameter by 72.9 mm (2.88 in) length, with a weight of approximately 0.34 kg (12 oz).

Options & Accessories

The following options are available to modify the standard configuration:

• PSW12-CL: Cover lock for security
• PSW12-MB: Mounting bracket for easy retrofit
• GND: External grounding screw (required for non-metallic conduit systems)

Key Product Differences

The PSW-12 series distinguishes models by diaphragm type and switch configuration. Models with the "T" prefix utilize a PFA-coated Polyimide Diaphragm, while those with the "V" prefix feature an FKM O-ring design. Switch types are designated as Single (S) or Dual (D), corresponding to SPDT or DPDT outputs respectively.

Adjustable ranges and deadbands vary by model suffix (AS through HS). For example, PSW12T-AS covers a fall/low range of 8 psi (0.6 bar) to a rise/high of 30 psi (2.1 bar), whereas the high-range PSW12T-HS spans from 2000 psi (137.9 bar) up to 6000 psi (414.0 bar). Maximum working pressure and proof pressure limits increase with higher range models, reaching 8000 psi (551 bar) maximum working pressure for the HS variants.