Hobbs 4006‑4 Pressure Switch (NOS)

Hobbs 4006‑4 Low‑Pressure Switch — New Old Stock Industrial‑grade diaphragm‑type pressure switch used across generator sets, industrial engines, hydraulic systems, and legacy aviation/ground‑support equipment.

Specifications

• Manufacturer: Hobbs (Honeywell legacy line)

• Model: 4006‑4

• Type: Diaphragm pressure switch

• Function: Low‑pressure safety / indicator switch

• Electrical: SPST or SPDT depending on sub‑variant (most 4006‑4 units are N.O. to close on pressure rise)

• Thread: 1/8" NPT male (typical for 4000‑series)

• Setpoint: Variant‑dependent (commonly 3–7 PSI range)

• Terminals: Screw or blade terminals depending on production run

• Condition: NOS — unused surplus stock

Applications

• Industrial engines (Onan, Kohler, Wisconsin, Continental, Hercules)

• Generator sets (military, commercial, standby)

• Hydraulic systems

• Fuel pressure safety circuits

• Oil pressure warning circuits

• Legacy aviation ground‑support equipment