The KOBOLD RCD differential pressure flow meter is suitable for monitoring water and water-like liquids, measuring flow using the orifice principle. The metering orifice within the flow body generates a differential pressure that varies with flow rate. This differential pressure is applied to a measuring bellows and linked to either a 270° mechanical indicator or a Hall-Effect transducer signal feeding electronic display and controller options .

The RCD operates on the Venturi nozzle principle, where a small pressure difference proportional to flow is produced by the flowing medium at a cross-sectional constriction (nozzle) in the device housing. The shape of the nozzle is based on the particular flow value, maintaining constant flow characteristic over the entire measuring range. Pressure sensing ports in the flow body measure the resulting differential pressure and send it to a differential-pressure measuring cell in the display case.

The unique single measuring bellows design makes accuracy unaffected by system pressure fluctuations. The meter movement is a single fulcrum lever design that is simple yet very reliable with minimal wear parts. The metal design has no moving parts to wear out, featuring an ultra-rugged design for high reliability and long service life.

Available with bronze or stainless steel bodies in sizes from 1/2" NPT to 3" NPT, the RCD offers various electronic display and control units including digital or bargraph displays, adjustable switches, and flow transmitters. Custom calibrations for density and viscosity are available. The RCD-Z mechanical indicator provides 270° indication with NEMA 4X enclosure. The RCD-C compact electronics feature 3-digit LED display and 4-20mA 3-wire transmitter in 304SS NEMA 4X housing. The RCD-K digital and bargraph display controller offers 3-1/2 digit LED and bargraph display with two SPDT programmable setpoint relays.