FLOMEC® DP Series Insertion Meters

A Little Bit About FLOMEC® Insertion Meters

FLOMEC Insertion Flowmeters provide a cost effective and simple means to measure flow rate of water and a wide range of low viscosity liquids. A robust solution with 316SS body, and a durable PVDF or peek rotor with a graphite -PTFE impregnated peek bearing, rotates around a precision ground stainless steel rotor shaft to promote longevity.

Operating Principle

Flow passes through a causing the rotor to spin. There are magnets installed in the rotor that pass by pulse sensors within the meter body, and this produces outputs that are proportional to flow rate.

What Are Some Insertion Flowmeter Features?

A decidedly advantageous feature is quick and inexpensive installations for pipe diameters ranging from 40mm to 900mm and up to 2500 nominal bore for the Hot Tap capable model DP525.

Two independent pulse outputs are standard and can directly input to a wide range of ancillary instruments, PLC’s and computers. Both pulse outputs have a high level of immunity to electrical interference. The FLOMEC Insertion Flowmeter is capable of accurately measuring flow in both directions without any modification. Some other features include minimal pressure loss and high-pressure submersible design.

Options are available for:

• High-temperature applications
• Reed switch for intrinsically safe areas
• Integral or remote high speed pre-set batch controller
• Optional Quadrature Hall (QP) pulse with bi-directional discriminator output
• Non-magnetic rotor option for liquids containing ferrous suspensions

A Little Bit On Reed Switches

The Reed switch output is classed as a “simple apparatus” as defined in the CENELEC standard EN50020 and recognized IEC and ATEX directive. It can be connected to an approved I.S secondary instrument with both being located in the hazardous area. The reed switch may also be connected through an approved I.S barrier. Note: The reed switch produces 1/3rd the normal pulse output value (1/3 the standard K-factor).

Innovative Design

The metering head of the FLOMEC Insertion Meter is shaped to encourage a conditioned flow profile at the aerofoil shaped rotor. The combination of these unique features extends the linear measuring range to cover flow velocities from 0.3 – 10 meters/sec, (1.0 – 33 feet/sec) without creating flow cavitation.

High-Level Voltage Pulse?

High-Level Voltage Pulse: A self-generating output requiring no power source and produces a strong 1.5-volt output spike of approximately 10 microseconds duration with no dependence on rotor speed. You would use this option to connect to self-powered instruments such as FRT12 which is battery powered. Square Wave Output: An open collector pulse output produced by a solid state Hall Effect device. This three wire device requires 5-24VDC excitation voltage and produces a high-resolution NPN square wave conditioned output.
You would use the square wave output option to connect primarily to PLC’s which require external or loop power.


Choose an appropriate section of horizontal or vertical pipe (more details in flowmeter manual). For vertical installations, the fluid should be pumped up through the pipe past the flow sensor so that any entrained air will pass freely. The FLOMEC Insertion Flowmeter sensor requires a fully developed turbulent flow profile to ensure maximum measurement accuracy and repeatability. Two typical installation arrangements are illustrated in the diagrams below.

Some Guidelines on How to Assure Uniform Flow:

Ideally, flow must be uniform at the joint where the flowmeter is installed. To assure uniform flow, avoid the common causes of obstructions such as partially closed valves, pipe bends, check valves, tee junctions, sharp increases in line size, Y- junctions and restrictive valves or fittings. Allowing adequate length of straight pipe for flow to stabilize and return to a uniform state before entering the metering device.

What Is Hot Tapping? 

Definition of Hot Tapping: Hot tapping
or pressure tapping, is the method of making a connection to existing piping or pressure vessels without the interruption of emptying that section of pipe or vessel. This means that a pipe or tank can continue to be in operation whilst maintenance or modifications are being done to it.
One of the many advantages of hot tapping is that you don’t have time lost on the production line.
Hot tap installation should only be performed by qualified personnel. Installation procedures should be in accordance with the safety requirements and regulations relevant to the territory in which the meter is being installed.