Flowmeters

Flowmeters measure how much liquid, gas or steam passes through a pipe, as a volume or a mass. Seven Star LLC, the agency for pFlow in Oman and the GCC, supplies flow meters for water, chilled water, compressed air, steam, oil and gas, with items from pFlow, ABB, Endress+Hauser, KROHNE and Yokogawa, among others.

The category covers inline, insertion, clamp-on and portable instruments across the main measuring principles.

Flowmeter types in the category

Ultrasonic meters form the largest group. pFlow supplies inline and multipath meters, chilled water and HVAC versions, portable units and small sensors for micro flow. Katronic, Micronics and Dynasonics add clamp-on ultrasonic flow meters, fixed and portable, some with heat metering for energy measurement, and Panametrics covers ultrasonic flow transmitters. Electromagnetic meters, from makers such as ABB and Endress+Hauser, measure conductive liquids such as water, wastewater and slurries. ABB differential pressure meters include integral orifice and averaging pitot designs, and the Rosemount 3051CF combines a DP transmitter with a primary element. Yokogawa vortex meters suit steam and gases. Variable area meters, KRACHT gear meters for oils and low-flow meters from Titan Enterprises complete the list.

How to choose a flow meter

Each principle has conditions. Electromagnetic meters need a conductive liquid and a full pipe, and have no moving parts. Transit-time ultrasonic meters need a fairly clean fluid; clamp-on versions measure from outside the pipe, which avoids cutting the line. Coriolis meters measure mass flow directly. Vortex meters need a minimum velocity to produce a signal. Orifice plates and similar differential pressure elements are standardized in ISO 5167 and work on almost any fluid, with a permanent pressure loss. Most principles also need straight pipe upstream and downstream, as stated in the manufacturer’s manual. Meters for classified areas need ATEX or IECEx certification, and meters used for billing may need a pattern approval such as MID or OIML.

What to send for a flowmeter quotation

• Fluid, and for liquids the conductivity and solids content
• Line size, pipe material and wall thickness
• Minimum, normal and maximum flow
• Operating pressure and temperature
• Outputs, power supply and area classification

For a replacement, the full order code from the nameplate lets us check the configuration against the manufacturer documentation and propose the manufacturer’s successor if the model is obsolete.