LEFOO LF727 Diaphragm Pressure Switch

LEFOO LF727 original product photo — LEFOO LF727 · Manufacturer image and specification

LEFOO LF727 is a diaphragm pressure switch. Correct selection depends on the actual switching range, process medium, terminal construction and the intended control/safety function.

LF727OEM-approved process media by wetted materialsManufacturer model family

Model Identification & Specifications

ManufacturerLEFOO

ModelLF727

Device technologyDiaphragm pressure switch

Process mediumOEM-approved process media by wetted materials

Manufacturer switching envelopeSetpoint bands 1–5 to 20–50 bar by ordered type

Operating / proof limitsBrass body 40 bar operating / 80 bar burst; stainless/steel 150 / 300 bar

Electrical signalSPDT switch; model termination and load class to confirm

Order-code scopeManufacturer configuration sheet determines final claims

Important: Operating, proof and burst are not interchangeable limits. A published pressure class does not give every connector, material and switchpoint variant the same rating.

Verified Manufacturer Technical Notes

SPDT diaphragm model: plated or stainless steel maximum operating pressure 150bar versus brass 40bar; 300bar and 80bar are BURST limits, not valid operating or switching setpoints. Factory selectable 1–5 through 20–50bar ranges, with 20–50bar option excluding brass; electrical and ingress rating vary by connector.

Choose the pressure switchpoint and reset differential for the actual operating cycle; confirm compatible wetted materials, connection, pressure direction, electrical contact topology, working ambient and ingress protection with the exact order code. Check actual connection, contact rating and available manufacturer conformity documents for the selected model.

Engineering Selection — AirAlign Analysis

The 20–50 bar adjustment band is not a brass-body option. A stainless housing’s pressure rating cannot be inherited by a brass variant, and burst pressure is never a permissible working setpoint.

For a control loop, choose the actual trip and reset behavior first. A mechanical contact can provide alarm, protection or run/stop control but does not output a continuously calibrated measurement. Check any fail-safe state, wiring to the final load, switching cycle frequency, differential setting and the process connection before replacing a physically similar part.

Installation, Wiring and Media Compatibility

Electrical interface

Check normally-open/closed wiring, the contact’s inductive versus resistive load, switching duty and whether the output is a low-current signal or suitable for direct equipment control.

Pressure boundaries

Choose the manufacturer-defined switchpoint and reset hysteresis, and verify the maximum admissible steady-state pressure separately from any short-duration proof or burst figure.

Wetted materials and fittings

Confirm gas/liquid approval, diaphragm compatibility, port size, connection thread and physical mounting orientation against the exact order code. Some products are intended only for non-hazardous gases.

Environmental and certification scope

IP grade and electrical approvals vary with connector and enclosure. Check the actual model suffix and connector or enclosure variant against the applicable manufacturer certificates.

Official Manufacturer Resources

LEFOO LF727 manufacturer source / document

LF727 — diaphragm versus plunger mechanism

LF727 uses a diaphragm switching element and should be selected by process-medium compatibility and the needed make/break differential. In a pump or compressor circuit, validate overload peaks and contact duty, not only the nominal threshold. The LF727A and LF727B high-pressure alternatives use different construction/pressure selection and must not be assumed mechanical drop-in equivalents.