Why Standard Flow Switches Fail at High Pressure
Standard paddle-type flow switches use a bellows or diaphragm to isolate the micro-switch from the process fluid. At pressures above 600 PSI, these flexible elements can fail, allowing process fluid to enter the switch housing — a potentially catastrophic failure in hazardous service.
The PEECO H Series uses a solid rod and flexure tube design that eliminates the bellows entirely. The flexure tube is a precision-machined solid stainless steel component that flexes slightly under paddle deflection — transmitting motion to the micro-switch without any dynamic seals exposed to full system pressure.
H Series Design Advantages
Up to 10,000 PSI
Field-tested at extreme pressures in oil & gas, hydraulic power units, and high-pressure water jet systems.
No Bellows to Fail
Solid rod and flexure tube design eliminates the most common failure mode of standard flow switches.
Explosion Proof
Class I, Division 1, Group D. Suitable for hazardous locations common in oil & gas facilities.
Custom Line Sizes
Available for line sizes from 1/4″ to 36″+. Contact PEECO engineering for large-bore applications.
Typical Specification
| Series | H Series (High Pressure Explosion Proof) |
| Max Pressure | Up to 10,000 PSI (field tested) |
| Line Size | 1/4″ – 36″+ |
| Max Temperature | 300°F standard / 1,500°F optional |
| Body Material | Carbon steel, 316SS, or Monel |
| Classification | Class I, Division 1, Group D |
| Micro-Switch | SPDT 15A 125-250 VAC (standard) |