SMC PF3W720-03-A-M Digital Water Flow Switch

Overview

SMC PF3W720-03-A-M is an integrated digital flow switch for water and aqueous glycol solutions, belonging to the SMC PF3W7 series. SMC PF3W720-03-A-M adopts Karman vortex detection principle, measures instantaneous flow and accumulated flow, and provides two independent NPN switch outputs for flow monitoring, alarm and interlock control. This SMC PF3W720-03-A-M is widely stocked as spare liquid flow monitoring unit for cooling water and industrial fluid automation assemblies.

Features

SMC PF3W720-03-A-M Flow Switch supports 3-color local display for flow value and status indication. Two NPN switching outputs can be independently configured as upper limit, lower limit, window comparison or hysteresis alarm. PF3W720-03-A-M has built-in accumulated flow counting function, supports flow reset and batch monitoring. It is equipped with overcurrent and short-circuit protection for output circuits. The wetted parts are stainless steel 304 and FKM seal, compatible with clean water and low viscosity ethylene glycol aqueous solution. This unit is IP65 rated, suitable for machine side installation. It supports simple calibration and parameter setup via front push buttons, and provides fault self-diagnosis for abnormal flow or sensor error. It is CE, UL and RoHS compliant, designed for 24/7 continuous operation on machine tool cooling circuits, laser chiller lines and packaging equipment water loops.

Specifications

SMC PF3W720-03-A-M Digital Water Flow Switch Brand: SMC Model: PF3W720-03-A-M Series: PF3W7 Type: Karman vortex flow switch for water Port size: Rc 3/8 Rated flow range: 2 ~ 16 L/min Output type: OUT1 NPN, OUT2 NPN Unit setting: M (L/min, L, ℃) Power supply: 12 ~ 24 VDC ±10% Max load current: 50 mA per output Fluid temperature: 0 ~ 90 ℃, no freezing or condensation Ambient temperature: 0 ~ 50 ℃ Wetted material: SUS304, FKM Protection class: IP65 Display: 3-color digital display Mounting: bracket mounting Status: active SMC liquid flow spare

Principle

SMC PF3W720-03-A-M generates Karman vortex when liquid flows through the internal bluff body. This Digital Water Flow Switch detects vortex frequency and converts it into flow rate value. It compares the measured flow with preset threshold and triggers NPN output signal. The module also records accumulated flow and continuously monitors sensor working status. When flow exceeds or falls below the set range, it sends switch signal to PLC for alarm or equipment interlock.

Applications

SMC PF3W720-03-A-M is deployed in CNC machine cooling circuits, laser chillers, injection molding machine water circuits, packaging equipment and industrial water circulation systems. It monitors cooling water flow, protects spindle and laser source from insufficient flow. SMC PF3W720-03-A-M is stocked as spare digital flow switch for liquid flow monitoring automation assemblies.