Introduction to Flow Meters

INTRODUCTION TO FLOW METERS

What are Flow meters

A flow meter is an instrument used to measure linear, nonlinear, mass or volumetric flow rate of a liquid, steam or a gas.

Selecting a Flow meter

The basis of good flow meter selection is a clear understanding of the requirements of the particular application.

Evaluating the nature of the process fluid and of the overall installation.

Innovative Technologies, Creative Solutions

Quality & Simplicity in Flow Measurement

Key questions which need to be answered before selecting a flow meter:

What is the fluid being measured by the flow meter. Do you require rate measurement and/or totalisation from the flow

meter? What viscosity is the liquid? Characteristics of the fluid (Is the fluid clean, have particles?) Do you require a local display or do you need a signal output? What is the minimum and maximum flow rate ? What is the minimum and maximum pressure? What is the minimum and maximum temperature? Is the fluid chemically compatible with the flow meter ? If this is a process application, what is the size of the pipe?

SELECTING A FLOW METER

FLOW METER SELECTIONHow To Select a Flow meter Line Size – Do not choose meter on line size. Flow Range – Same size meters can have totally different flow

ranges. Fluid Compatibility – Check meter materials of manufacture

are compatible with fluid. Viscosity –Flow de-rating factors or limits may apply. Connections –Pressure rating of meter flanges. Protection – Choose correct mesh size for strainers. Accuracy & Repeatability – Repeatability is the more

important parameter

The turbine meter normally has an accuracy of 0.5% of the reading. It is a very accurate meter and can be used for clean liquids and viscous liquids up to 100 centistokes. A minimum of 10 pipe diameters of straight pipe on the inlet is required. The meters consists of a multi-bladed rotor mounted at right angles to the flow and suspended in the fluid stream on a free-running bearing.

TURBINE FLOW METERS

One of the most popular cost effective flowmeters for water or water like fluids. Many are offered with flow fittings or insertions styles. These meters like the turbine meter require a minimum of 10 pipe diameters of straight pipe on the inlet and 5 on the outlet. The rotor of the paddlewheel sensor is perpendicular to the flow and contact only a limited cross section of the flow.

PADDLEWHEEL SENSORS

Positive Displacement meters come in various configurations & are a very versatile flow meter, best suited for high viscosity & non–conductive liquids. They have high accuracy (linearity & repeatability) with low flow and precise batch capability.

Meter requires no flow conditioning for simple installation and are easy to understand & service.

Oval Gear

Rotary Piston

POSITIVE DISPLACEMENT FLOW METERS

OVAL GEAR FLOW METERS

Positive Displacement Oval Gear Flow Meters

Among the many Positive Displacement flow meter design principals available today, the oval gear wheel still holds a top place in simplicity & field proven performance.

GEAR WHEEL FLOWMETER


OPERATION OF OVAL GEAR FLOW METER


Trimec Flow Products Oval Gear Wheel meters provide high levels of accuracy & repeatability for a wide range of clean liquids irrespective of viscosity & conductivity either pumped or gravity fed.


Flow range: 0.5 litres / Hr ~ 2500 litres / min. Nominal sizes: 4mm ~ 100mm pipe size Linearity: +/- 0.5% of reading ( +/- 0.2% with

linearisation ) ( +/- 1% for Mechanical Displays ) Repeatability: +/- 0.03% Temperature: -20 ~ +120 Deg C - Standard Materials: aluminium or 316 stainless steel Pulse outputs: reed & NPN open collector Mechanical Displays: 3 ,4 & 5 digit

General Specifications Oval Gear Flow Meters


Optional Rotor Material - on all meter sizes

( excludes extended flow versions )

Rotor Stability ( On Metal Rotors )

120 Deg. Temp. Rating. ( High temp rotors not required )

Aluminium, Ryton & Stainless Steel materials.

Metal Roller, Carbon or Ceramic Bearings.

BENEFITSMeter Features


Modular Process Connections

Available on 25mm to 100mm meter sizes.

Simplifies Installation

Screwed or Flanged connections.

Stainless option on screwed versions.


Meter Features

Dual Outputs ( reed & Hall ) Standard.

Quadrature Pulse Output Option.

Pulse Interrogation connection

High Pulse Output option ( Hall only )

Pulse Output BoardsMeter Features


Low & High Flow Capabilities

Broad Range 1/8” to 4” 0.5 LPH to 2500 LPM

High Precision +/- 0.5% Optional +/- 0.2% with linearization

Unaffected by pulsations

No Flow Conditioning required


Meter Features

Available as pulse meter only or with integral or remote mount LCD or mechanical registers.

Dual Outputs ( reed & hall) as standard. Weatherproof IP66 / 67 LCD models Flameproof / Explosion proof construction Atex & IECeX Intrinsically Safe Integral Instruments. Modular connections for adaptability and ease of installation and service. Quadrature pulse output option for pulse verification or forward / reverse

measurement. High Flow Capabilities ( 2500 lpm ) NMI Certification ( Resale Purposes ) meter sizes 1” to 4” fitted with air

eliminator strainer and approved register.


Meter Features

High Precision / High resolution ( Pulses per Litre ) 120 Degree Temperature Rating as standard. High & Low viscosity applications. 3 , 4 or 5 digit Mechanical Registers with large number

displays. ( Metal Housings with or without accuracy adjustment )

Gearbox fitted with stainless steel gears as standard. Aluminium rotors fitted with high speed roller bearings. Stainless rotors fitted with ceramic or carbon bearings. Ryton Rotors Viton seals as standard.


Meter Features

Advantages Opposition Metal & Plastic Rotors Metal & Plastic Modular Connections Cast in meter body Higher Temperatures -120deg 80 deg. Higher Flows 25mm size – 150 lpm 120 lpm Larger Flow Range – 2500 lpm 1200 lpm More Models – Extended Capacity N/A Ductile Iron material N/A ATEX & IECex approvals N/A NMI approval Mechanical Meters N/A Accuracy Adjustment – Mechanical N/A Viton seal standard Nitrile Electronics – own manufacture Fluidwell / Flux Gearbox – stainless gears Plastic Gears Large size reset number display Small reset numbers


Meter Features

Low Pressure Drop standard feature. Extended Flow Models available in 2”, 3” & 4” sizes. Factory calibration & accuracy certificate supplied. Flexibility of Installation. ( vertical or horizontal lines )

Min. number of moving parts in LCD pulse meters ( 2 Rotors )

Continued product development commitment.

Standard Meter – Pulse Output Options ~ LCD Register ~ Mechanical Register ~ Batching Register


Meter Specifications:

2 RotorsReed Switch

Meter Specifications:


Minimum number of moving parts in pulse meters

Meter Selection


Meter max. flow rates are based on 1 bar pressure drop With Fluids above 1200 cps. Meter sizing and required flow rate

become important decisions. To achieve the lowest possible pressure drop, a range of special

cut “ Keishi” high viscosity optional rotors are available. The Dimak series oval gear meters are extremely suited to

measuring highly viscous materials with the pressure drop being the only limiting factor.

Special rotors applies to meters sizes TF-008 to TF-100 also refer to de-rating factor for reduced flow rates applicable

Flowmeters Depending on the fluid

viscosity the flow meters maximum flow rate may be de-rated according to the attached chart. Example:- TF25 meter measuring oil @ 6000 Cp Max Flow 150 lpm x 0.5 = 75 lpm new maximum flow rate to maintain 1 bar pressure drop.

VISCOSITY CORRECTION


Special Cut Rotors:

Above 1200 cps.

Every 3rd Tooth Removed

Oval Gear Rotor

VISCOSITY


Accuracy & Pressure Drop Curves


FBT11 Battery Powered Totaliser REMOTE OR INTEGRAL METER

MOUNT Simultaneously displays re-settable

(batch) total in engineering units as programmed by the user. When externally dc powered the instrument will produce an un-scaled or scaleable solid state output pulse which is NPN / PNP selectable.

FLOW INSTRUMENTATION PRODUCTS

FRT12 Flow Rate Totaliser

REMOTE or INTEGRAL METER MOUNTING

Simultaneously displays re-settable (batch) total & cumulative total in engineering units. When externally dc powered the instrument will produce an un-scaled or scaleable solid state output pulse which is NPN / PNP selectable.


FRT-40 Flow Rate Totaliser REMOTE or INTEGRAL METER

MOUNTING Battery or External powered, 6 digit large

LCD total & 8 digit cumulative totaliser, with 5 digit rate display.

IP66/67 ~ Nema 4X aluminium housing. LCD Backlighting as standard. Scaled Pulse Output. Optional facia protection shield Metal Housing as standard


FEB10 Batch Controller

REMOTE or INTEGRAL METER MOUNTING

Provides automatic batch control with one or two stage outputs. Display provides batch quantity as well as status at each stage of the batch process. Batch limiting & no flow detection plus automatic over run compensation. Other features include remote stop / start, system interlocks and multiple batch controller networking.


When fitted to flow meter, the cooling fin allows meters to be fitted with electronic display to be rated to 120 deg C

Compact design allows adequate heat dissipation in ambient temperatures

ANCILLARY PRODUCTS

Cooling Fin

FI-420 Frequency Converter

The Frequency converter is a programmable, non volatile PCB which is link selected to serve as either a frequency to current converter (F/I) or a single point flow rate alarm device for high or low rate detection - Board fits onto flow meter output PCB. FI-420 Programmed at factory

or in situ with hand held programmer

ANCILLARY PRODUCTS

RELAY OUTPUT BOARD

The relay output boards are an option for the Z3 & B1 Instruments. The relays will switch higher loads ( 5 Amp ) than the solid state switches provided as standard in these instruments

ANCILLARY PRODUCTS

PD2 Pulse Discriminator ModuleApplication is for discriminating bi-directional flows. Accepts two independent inputs from flow meters with quad pulse outputs. Discriminates flow direction from inputs and provides forward & reverse pulse outputs for each flow direction

ANCILLARY PRODUCTS

PR2 Pulse Repeater Module

The pulse repeater provides electronic protection to the flow meter output in situations where associated external circuitry may have heavy electronic loadings, non regulated power supplies or electrical surges or spikes

ANCILLARY PRODUCTS

Exd Explosion Proof Housing

Robust aluminium or stainless field mount housing.

Four Large external non- invasive operational switches.

IP66 ~ Nema 4X Rated. View, program & operate instruments

without cover removal. Certifications – FM, ATEX, SAA

Flow Instrumentation Products

ANCILLARY PRODUCTS

Mechanical Registers Standard - without accuracy adjustment

As an alternative to electronic totalisers, robust mechanical registers with metal housings offer 3 or 4 large resettable digits & 6 or 8 accumulative total displays clearly visible for loading & un-loading sites at petroleum depots, mining, construction & marine facilities

M1 Register

M3 Register


ANCILLARY PRODUCTS

Mechanical Registers V Style - with accuracy adjustment As an alternative to electronic totalisers,

robust mechanical registers with metal housings offer 5 large re settable digits & 8 digit accumulative total displays clearly visible for loading & un-loading sites at petroleum depots, mining, construction & marine facilities

V1 Register with accuracy adjuster

ANCILLARY PRODUCTS


Ticket Printers Meter Register and Ticket

Printer combine together to produce clean, detailed printed records of high speed fluid deliveries and transactions

ANCILLARY PRODUCTS


Mechanical Preset Batch Registers As an alternative to electronic

batch controllers or in Ex Proof applications, mechanical preset registers with shutoff valve are available in sizes from 2” to 4”

ANCILLARY PRODUCTS


STRAINERS

As the meters are only suitable for clean liquids it is important that any impurities are removed prior to the meter.

Typical Y Strainer

SIZEMesh Size

Micron Size1/4" 200 mesh 75 DN83/8" 200 mesh 75 DN101/2" 100 mesh 150 DN151" 50 mesh 250 DN25

1 1/2" 50 mesh 250 DN402" 25 mesh 500 DN503" 25 mesh 500 DN804" 25 mesh 500 DN100

Recommended Mesh Sizes

ANCILLARY PRODUCTS

HIGH PRESSURE METERS

High Pressure Models Sizes up to 50mm

Pressures to 400 Bar (6000 PSI ) Special end connections available Hall effect output Deep Sea applications Chemical Injection Hydraulic applications

HIGH PRESSURE MODELS

Every Flowmeter undergoes a

check before leaving the factory for correct operation & function of pulse outputs & ancillary electronics if fitted.

Meters are then compared against a master meter which is traceable to the Australian National Standards & issued with a calibration report.

FLOWMETER CALIBRATION

Company has 4 meter calibration test benches using certified master meters for validating meter accuracy.

Small meters to 750 l/hr. Medium meters to 500 l/min. Large meters to 1500 l/min.

METER CALIBRATION

Installation Points: PD Meters do not work well with silty or dirty fluids

( Use Strainers before meter ) Straight Pipe not necessary before meter. Teflon Tape can cause rotor stoppages. High Velocity flows can cause rotor destruction

( Slowly ramp up flow on start up ) Avoid Water Hammer caused by closing valves

quickly in batch applications Flush Pipe Lines prior to meter installation

POSITIVE DISPLACEMENT METERS

strainer

Flow meterisolation

valveisolation

valve

by-pass valve Open downstream

valve last

TROUBLE SHOOTING

Symptom Solution1. 1. Ground shield of signal cable

2. Re-route cable from high electrical energy sources

2. 1. Remove source of air or gas entrapment2. Install an upstream air eliminator

3. 1. Increase back pressure on pump2. Install a fast response one way check valve3. Install a surge arrestor between pump & meter4. Re-calibrate meter in situ to compensate for pulsations5. Change pump style to smooth delivery type pump

1. Damaged or 1. Inspect, repair, clean or replace rotorsworn rotors

2. 1. Inspect measuring chamber for damage - repair2. Check concentricity of rotor shafts within chamber

3. 1. Ground shield of signal cable2. Re-route cable from high electrical energy sources3. Check all electrical terminations & wires for continuity.

1. Rotors fouled 1. Check that rounded teeth are towards base of chamber2. Check for obstruction due to foreign particles3. Clean, repair or replace rotors

2. 1. See instructions for reassembly of meter withparticular emphisis on positioning of rotors & magnets

3. 1. Check terminal connections & solder joints2. Ensure dc voltage is available at Vdc & 0v and

receiving instrument is fitted with a pull up resistor3. Replace output board

1. 1. Check DIP switch settings & program data2. Check terminal connections & electrical continuity3. Repair / replace receiving instrument

Possible causeOutput signal interference

Pulsating flow from

reciprocating style pump

Damaged or worn

measuring chamber

No output from output board

Faulty receiving

instrument

Meter incorrectly

reassembled

Meter readings are high

Output signal interference

Meter readings are low

Entrained air or gas

No output from meter

Not reading

on readout

It is important when starting up the process that the downstream valve is slowly opened last

RECOMMENDED INSTALLATION

Specialised Fuel Meters

Low cost fuel flow meters designed for monitoring of fuel in Trucks, Buses & vehicles

EM008 Meter

EM025 Meter

Additional Products

ADDITIONAL PRODUCTS

Acids Alcohol Water Fuel Oils Diesel Liquid Propane Bitumen / Asphalt Tallow Paint Pharmaceuticals

METER APPLICATIONS

Pesticides Solvents Chemicals Foods Beverages Vegetable Oils Inks Adhesives Hydraulic Oil Resins

METER APPLICATIONS

INDUSTRY USAGE

Aviation Fuel Management, water & chemical loading / unloadingBeverages Alcoholic Spirts , Fruit Juices - MilkCement / Ceramic / Glass Additives , WaterChemical Ammonia, Caustic Soda, Methyl Chloride, Butane, AcetonesConstruction Fuel, OilsCosmetics Perfume, Foundation Creams, Alcohol, Shampoo, soapsEnergy Fuel, Water, Freon, LPG.Food Industry Sauces, Pastes, Glucose, Chocolate, Yeast, Mayonaise.Gas & Oil Mecapatans, LPG, Additives, OilsLubrication Oils, Coolants, Hydraulic fluidsMarine Fuel monitoring, Loading / Unloading

METER APPLICATIONS

INDUSTRY USAGE

Metal Manufacturing Release Agents, Acids, Water, OilsOils & Fats Vegetable Oils, Cooking Oils, Lards, Tallow.

Paints / Ink Paints, Solvents, Printing Inks

Petrochemical Ethylene Oxide, Propylene, Vinyl Chloride, Monomers. Petroleum Heavy Oil, Gasoline, Bitumen, Kerosene, Napthia.Pharmaceuticals Alcohol, Water, Syrups, Glycerine, Liquid Sugar

Pulp & Paper Dyes, Acids, Additives.

Semi- Conductor Acids, Solvents, Chemicals.

Textiles Dyes, Bleaches, Chemicals.

Toiletries Shampoo, Conditioner, Alcohol, Gels.

Transport Fuel Monitoring, Tanker Loading / Unloading

Water treatment Fluoride, Acid Addition, Chemicals, Flocculants.

METER APPLICATIONS

Documents

Introduction to Flow Meters