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Big Hermet Hermetically Sealed Pressure Switch (BA Series)

Name: Big Hermet Hermetically Sealed Pressure Switch (BA Series)
Brand: SOR

The SOR Big Hermet Hermetically Sealed Pressure Switch (BA Housing Series) is an industrial-grade pressure control switch engineered for panel and wall mounting in severe processing environments where easy access, corrosive atmospheric protection, and high reliability are critical. Featuring a snap-action switching element hermetically sealed inside an explosion-proof steel capsule with glass-to-metal seals, electrical contacts are completely isolated from ambient humidity, chemical fumes, salt spray, and corrosive gases. Utilizing SOR's Static O-Ring force-balance sensing mechanism with minimal mechanical travel (just thousandths of an inch), the switch delivers exceptional repeatability (±1% of span), negligible temperature effect, and high tolerance to cycle rates and mechanical vibration. Operating ranges span from 30 in Hg vacuum to 7,000 psi (480 bar) with an extensive selection of elastomeric and metal diaphragms (Buna-N, Viton, Kalrez, 316L SS, Monel, Hastelloy), SIL 2 functional safety certification, and backed by SOR's 3-year limited manufacturer warranty.

Hermetically sealed steel capsule snap switch isolates electrical contacts from corrosive atmospheres, H2S, moisture, and salt air

Set point adjustment is easily performed in the field without declassifying the hazardous area or opening sealed switch capsules

Static O-Ring force-balance piston mechanism provides high repeatability (±1% of span) with low friction and virtually zero mechanical wear

Broad adjustable ranges from 30 in Hg vacuum up to 7,000 psi (480 bar) across 15 piston/spring spans

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Adjustable Set Point Span30 in Hg Vac to 7,000 psi (1 bar Vac to 480 bar) across 15 piston/spring ranges

Repeatability±1% of full adjustable span

Enclosure ProtectionNEMA 4, 4X, IP65 Weatherproof (Copper-Free 356 Cast Aluminum BA Housing)

Switching CapsuleHermetically sealed steel capsule (KB SPDT 15A, EB DPDT 5A, JR/JB Gold contacts)

Switch ApprovalSwitching capsule is UL Listed, CSA Certified, SAA Approved as snap switch for hazardous areas

Process Connections1/4" NPT Female standard | 1/2" NPT Female optional (316SS, Aluminum, Brass, Monel)

Conduit Connection3/4" NPT Female with 18" 18 AWG color-coded wire leads

Ambient Temperature Limit-40 °F to 167 °F (-40 °C to 75 °C)

Proof Pressure RatingUp to 6,000 psi (410 bar); Overrange up to 5,000 psi (340 bar)

Safety & Quality ApprovalsIEC 61508 SIL 2 Certified, ISO 9001 Quality System Registered

Standard WarrantySOR 3-Year Limited Warranty

Engineering Specifications & Selection Matrix

SOR Big Hermet BA Series Hermetically Sealed Pressure Switch Technical Guide

Configure your SOR Big Hermet BA pressure switch by selecting piston/spring range, switching element, wetted diaphragm materials, process connection metallurgy, and accessories.

Operating Span30 in Hg Vac to 7,000 psi (480 bar)

Housing ProtectionNEMA 4, 4X, IP65 Cast Aluminum

Switching CapsuleHermetically Sealed Steel Capsule

Safety RatingSIL 2 Certified / 3-Year Warranty

Piston & Spring Range Selection

12-4Piston 12, Spring 4: 0.5 to 6 psi (35 to 415 mbar) [Proof 400 psi / 27 bar]

4-4Piston 4, Spring 4: 2 to 25 psi (0.14 to 1.7 bar) [Proof 1,000 psi / 70 bar]

6-3Piston 6, Spring 3: 12 to 100 psi (0.8 to 7 bar) [Proof 2,500 psi / 175 bar]

5-3Piston 5, Spring 3: 25 to 240 psi (1.7 to 16 bar) [Proof 6,000 psi / 410 bar]

9-5Piston 9, Spring 5: 200 to 1,000 psi (14 to 70 bar) [Proof 6,000 psi / 410 bar]

9-45Piston 9, Spring 45: 200 to 1,750 psi (14 to 120 bar) [Proof 6,000 psi / 410 bar]

1-45Piston 1, Spring 45: 500 to 4,000 psi (35 to 275 bar) [Proof 6,000 psi / 410 bar]

Housing & Service Style

BAWeathertight NEMA 4, 4X, IP65 Copper-Free Cast Aluminum with Hermetically Sealed Switch Capsule (3/4" NPT conduit)

Switching Element

KBSPDT Hermetically Sealed Capsule: 15A @ 125/250 VAC, 0.4A @ 125 VDC, 5A @ 30 VDC (Deadband x1.0)

EBDPDT Hermetically Sealed Capsule: 5A @ 125/250 VAC, 0.5A @ 125 VDC, 5A @ 30 VDC (Deadband x3.5)

JRSPDT Gold Contacts for low-power DCS/PLC circuits: 1A @ 125 VAC, 1A @ 28 VDC (Deadband x1.0)

JBDPDT Gold Contacts for low-power DCS/PLC circuits: 1A @ 125 VAC, 1A @ 30 VDC (Deadband x3.5)

Diaphragm & O-Ring Materials (Wetted)

N4TCP (Teflon-Coated Polyimide) Diaphragm + Buna-N O-Ring (-30 °F to 200 °F) [Standard]

N1TCP Diaphragm + Viton O-Ring (32 °F to 400 °F)

N6TCP Diaphragm + Kalrez FFKM O-Ring (5 °F to 400 °F)

M4316L Stainless Steel Diaphragm + Viton O-Ring (32 °F to 400 °F)

M2316L Stainless Steel Diaphragm + Buna-N O-Ring (-30 °F to 200 °F)

A4Monel Diaphragm + Viton O-Ring (32 °F to 400 °F)

H4Hastelloy C Diaphragm + Viton O-Ring (32 °F to 400 °F)

Pressure Port Connection & Material

C1A1/4" NPT Female, 316 Stainless Steel (CF-8M Casting)

C2A1/2" NPT Female, 316 Stainless Steel (CF-8M Casting)

B1A1/4" NPT Female, 356 Cast Aluminum Alloy

G1A1/4" NPT Female, 303 Stainless Steel

Accessories & Options

CVCanadian Registration Number (CRN) Documentation

HTUniversal Stainless Steel Terminal Junction Box (1/2" NPT)

MMVacuum Protector Plate (for intermittent vacuum > 10 inHg)

NCCompliance to NACE MR0175 / ISO 15156

PKPipe / Stanchion Mounting Kit (1-1/2" to 2" Pipe)

PY316 Stainless Steel Tag with 304SS Wire

YYExterior Polyimide Epoxy Coating with 316SS Pigment

SOR Model Architecture

6BA-KB3-N4-C1A-YY

6PistonPiston #6 (12 to 100 psi span)

BAHousingBA Weathertight Aluminum Housing

KBSwitchSPDT Hermetic Steel Capsule 15A

3SpringRange Spring #3

N4DiaphragmTCP Diaphragm / Buna-N O-Ring

C1APressure Port1/4" NPT Female 316SS

YYAccessoriesPolyimide Epoxy External Coating

Technical specifications

Adjustable Set Point Span30 in Hg Vac to 7,000 psi (1 bar Vac to 480 bar)

Repeatability±1% of full adjustable span

Housing ProtectionNEMA 4, 4X, IP65 (Copper-Free 356 Cast Aluminum)

Switching CapsuleHermetically sealed steel capsule SPDT or DPDT

Process Connection1/4" NPT(F) standard | 1/2" NPT(F) optional (316SS, Alum, 303SS)

Conduit Connection3/4" NPT Female with 18" wire leads

Ambient Temperature Limit-40 °F to 167 °F (-40 °C to 75 °C)

Proof Pressure RatingUp to 6,000 psi (410 bar); Overrange up to 5,000 psi

Safety Integrity LevelIEC 61508 SIL 2 Certified for SIS circuits

WarrantySOR 3-Year Limited Manufacturer Warranty

Application & Field Safety Guidelines

External self-locking adjusting nut allows set point adjustment without declassifying the surrounding area.

The hermetically sealed steel capsule isolates switching contacts completely from harsh atmospheric gases and humidity.

Breather drain plug provides continuous enclosure ventilation and drainage of internal moisture.

For high-temperature steam service up to 400 °F (204 °C), select the M9 wetted system and install a pigtail siphon.

Product Overview & Design Architecture

The SOR Big Hermet (BA Housing Series) pressure switch is specifically designed for wall or panel mounting where accessible set point adjustment and protection against corrosive ambient air are paramount. In offshore platforms, pulp and paper mills, wastewater plants, and chemical refineries, corrosive atmospheres penetrate conventional unsealed microswitches, causing contact oxidation, pitting, and intermittent trips. The Big Hermet resolves this by sealing the snap-action switch inside a heavy-duty steel capsule with glass-to-metal lead seals.

The pressure-sensing assembly utilizes SOR's time-tested Static O-Ring force-balance system. Media pressure on the piston directly counteracts the range spring, moving the piston shaft only a few thousandths of an inch to actuate the switch capsule lever. This microscopic travel virtually eliminates seal friction and mechanical hysteresis, providing superior repeatability and extended cycle life.

Hermetically sealed capsule eliminates contact corrosion and oxidation caused by atmospheric humidity, ammonia, chlorine, or sulfur gases

Field set points are adjusted externally with a self-locking nut and calibrated scale without declassifying the surrounding area

Force-balance piston architecture provides robust vibration resistance and long operating life under continuous pulsation

Generous wiring space with standard 18" 18 AWG color-coded flying leads or optional junction box with screw terminals

Suitable for liquid, gas, vapor, and vacuum applications across a broad range of operating temperatures and pressures

Adjustable Span & Piston/Spring Selection Guide

Range 12-4 (Low Pressure)0.5 to 6 psi (35 to 415 mbar) | Deadband: 0.2 psi | Overrange: 200 psi | Proof: 400 psi

Range 4-4 (Medium-Low)2 to 25 psi (0.14 to 1.7 bar) | Deadband: 0.5 psi | Overrange: 750 psi | Proof: 1,000 psi

Range 6-3 (Standard Plant)12 to 100 psi (0.8 to 7 bar) | Deadband: 1.3 psi | Overrange: 1,500 psi | Proof: 2,500 psi

Range 5-3 (High Process)25 to 240 psi (1.7 to 16 bar) | Deadband: 3.0 psi | Overrange: 2,500 psi | Proof: 6,000 psi

Range 9-5 (Hydraulic / High)200 to 1,000 psi (14 to 70 bar) | Deadband: 14 psi | Overrange: 2,500 psi | Proof: 6,000 psi

Range 9-45 (Very High)200 to 1,750 psi (14 to 120 bar) | Deadband: 23 psi | Overrange: 2,500 psi | Proof: 6,000 psi

Range 1-45 (Extreme High)500 to 4,000 psi (35 to 275 bar) | Deadband: 150 psi | Overrange: 5,000 psi | Proof: 6,000 psi

Vacuum Ranges (52, 54, 56)52-117: 40-0-40 in.wc | 54-118: 30-0 inHg Vac | 56-216: 30 inHg Vac to 20 psi | 56-316: 30 inHg Vac to 160 psi

Switching Elements & Contact Configurations

KB Switch (SPDT Standard)SPDT Hermetic Steel Capsule, 15A @ 125/250 VAC, 0.4A @ 125 VDC, 5A @ 30 VDC (Dead Band Multiplier: 1.0)

EB Switch (DPDT Dual Circuit)DPDT Hermetic Steel Capsule, 5A @ 125/250 VAC, 0.5A @ 125 VDC, 5A @ 30 VDC (Dead Band Multiplier: 3.5)

JR Switch (SPDT Gold Contacts)SPDT Gold Contacts for low-current PLC/DCS I/O signals: 1A @ 125 VAC, 1A @ 28 VDC (Multiplier: 1.0)

JB Switch (DPDT Gold Contacts)DPDT Gold Contacts for redundant low-current signals: 1A @ 125 VAC, 1A @ 30 VDC (Multiplier: 3.5)

Diaphragm & O-Ring Wetted Materials Selection

N4 System (Standard)TCP (Teflon-Coated Polyimide) Diaphragm + Buna-N O-Ring (-30 °F to 200 °F) for air, water, lube oil

N1 SystemTCP Diaphragm + Viton O-Ring (32 °F to 400 °F) for hot petroleum oils and hydrocarbons

N6 SystemTCP Diaphragm + Kalrez FFKM O-Ring (5 °F to 400 °F) for aromatic solvents and aggressive chemicals

M4 System316L Stainless Steel Diaphragm + Viton O-Ring (32 °F to 400 °F) for corrosive process fluids

M2 System316L Stainless Steel Diaphragm + Buna-N O-Ring (-30 °F to 200 °F) for standard hydraulic oils

M9 System316L Stainless Steel Diaphragm + EPR O-Ring (-30 °F to 200 °F, steam to 400 °F) for steam service

A4 / A6 SystemMonel Diaphragm + Viton or Kalrez O-Ring for seawater, marine atmospheres, and sour gas

H4 / H6 SystemHastelloy C Diaphragm + Viton or Kalrez O-Ring for aggressive acids and halogens

Model Number Structure & Ordering Tree

SOR Big Hermet BA switches follow the modular model format: [1. Piston] [2. Housing] - [3. Switching Element] [4. Spring] - [5. Diaphragm] - [6. Pressure Port] - [Accessories].

Example Model: 6BA-KB3-N4-C1A-YY represents Piston 6 (12-100 psi span), BA Weathertight Housing with Hermetic Switch, KB SPDT Snap Switch, Spring 3, N4 Standard TCP/Buna wetted seals, C1A 1/4" NPT(F) 316SS pressure port, and YY Polyimide Epoxy Coating.

Housing DesignatorBA: Copper-free 356 cast aluminum housing (NEMA 4, 4X, IP65) with 3/4" NPT conduit entry

Switching ElementKB (SPDT 15A), EB (DPDT 5A), JR (SPDT Gold 1A), JB (DPDT Gold 1A)

Diaphragm OptionsN4 (TCP/Buna), N1 (TCP/Viton), N6 (TCP/Kalrez), M4 (316SS/Viton), M2 (316SS/Buna), A4 (Monel), H4 (Hastelloy C)

Pressure PortC1A: 1/4" NPT(F) 316SS | C2A: 1/2" NPT(F) 316SS | B1A: 1/4" NPT(F) Aluminum | G1A: 1/4" NPT(F) 303SS

Popular AccessoriesCV (CRN), HT (SS Junction Box), MM (Vacuum Protector Plate), NC (NACE MR0175), PK (Pipe Kit), PY (316SS Tag), YY (Epoxy Coat)