Overview
The Honeywell C437 Series gas pressure switch is a pressure-actuated control device engineered for industrial gas system applications, including combustion control, safety shutoff, pressure control, and differential-pressure control. The C437D,E Series 2000 Gas Pressure Switches are pressure-actuated switching devices used in industrial gas system applications for safety shutoff, pressure control, and differential-pressure control, with MicroSwitch snap switches to open or close a circuit on pressure rise or drop.
Key Features
- Direct- and reverse-acting SPST (non-mercury) switching
- Dust-resistant operation with enclosed setting
- Fiber-reinforced Buna-N control diaphragm and dual seal-off diaphragms for added reliability
- Clear glass cover for observation of interior mechanism to aid in setting and checkout
- Manual reset lever — models intended for lockout applications must be manually reset before resuming operation
- Models with low pressure ranges compensate for momentary surges in gas pressure with a restrictive orifice in inlet pressure channel
Technical Specifications
The C437 Series is available in multiple pressure range variants to suit different applications. Common specifications include:
- Pressure ranges available: 1/2 to 5-1/2 in. of water (0.1 to 1.4 kPa); 1 to 26 in. of water (0.5 to 7 kPa); 1/2 to 5 psi (3 kPa)
- Vent or Low Pressure connection: 1/8 in. NPT, female
- Main or High Pressure connection: 1/2 in. NPT; Vent or Low Pressure: 1/8 in. NPT, female
- Electrical Wiring: Hole tapped for 1/2 in. conduit
- Switching Action: Snap-acting MicroSwitch mechanism
- Reset Type: Manual reset
Typical Applications
C437 gas pressure switches are used in industrial gas system applications for safety shutoff, pressure control, and differential-pressure control. Common uses include:
- Natural gas furnace and boiler control
- Combustion air pressure monitoring
- Liquid petroleum gas (LPG) system regulation
- Differential pressure control for fan or blower interlocks
- Safety interlock circuits in gas appliances
Compatibility & Replacements
Compatible With
- Industrial gas control systems and safety interlocks
- Burner management and combustion control systems
- Pressure monitoring circuits requiring manual reset capability
- Standard NPT gas pressure piping (1/2″ and 1/8″ connections)
- Conduit wiring installations (1/2″ tapped hole)
Replaces / Drop-In Replacement For
The C437 Series includes multiple sub-variants (C437D and C437E families with different pressure ranges). Common model replacements include C437D and C437E series switches with matching pressure range specifications. Verify the specific pressure range (in inches of water column or psi) and reset type before ordering as a replacement.
Works With
- Gas pressure piping systems (natural gas, propane, compressed air)
- Standard 120 Vac and 240 Vac control circuits
- Boiler and furnace burner management systems
- HVAC interlocks and safety controls
- Field-installable pressure orifice accessories for surge compensation
