METAL VAREA-METER® STRAIGHT

THROUGH TYPE ROTAMETER

U.S. Filter/Wallace & Tiernan Products straight through metal tube Varea-Meters are

available in a variety of tube sizes and flange faces and ratings. These are suitable for

harsh process conditions and are designed for the measurement of high volume flows

of aggressive fluids and gases. They have high pressure and temperature limits and

give reliable flow measurements over a 10:1 range. As a standard feature, a rugged,

magnetically coupled flow indicator is provided. An optional flow transmitter

is available to provide local indication as well as a mA output.

TECHNICAL INFORMATION

INTRODUCING THE METAL TUBE VAREA-METER

FEATURES Anti-Magnetic-Particle FloatThe extra long float magnet has a reduced flux density and is located above the

metering disk. This discourages accumulation of magnetic particles, specially on

the disk edge where they can cause errors in indication. Meter design directs the

flow into a pattern, which scrubs the float and guides clean. The Varea-Meter is

ideal for suspensions and slurries.

Electronic Transmitter

FEATURES

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No Float ExtensionsWhen the float is at rest, nothing

projects beyond the flanges. Spool

pieces are not required for installation

and a frequent cause of damage when

removing meters from a line is gone.

In and out piping is vertical.

Reliable Magnetic CouplingFor reliable indication a powerful

magnetic linkage exists between the

float magnet and the indicator or

transmitter magnets. Transmission

and indication are reliable even under

sudden flow surges.

Easy Change-Out, Easy CouplingThe indication unit and the

transmitters are interchangeable.

A mounting clamp attaches them to

the meter tube. The same clamp

attaches a flow switch 180 degrees

from the indicator or transmitter.

Clearance between any of these units

and the tube leaves room for steam

or electric tracing.

Size for Size, Varea-MetersGive Greater Capacity, Cost LessViscosity immune Varea-Meter floats

have short lower bodies below the

metering disc. This permits greater

pressure recovery and restricts flow

less than other designs. These floats

permit tube-and-float combinations

which yield higher capacities for a given

tube size. A smaller size Varea-Meter

can be specified for a given capacity

at a cost saving.

Easy Field CalibrationStraight Through Varea-Meters can

be bench calibrated. After mounting

in process piping, a minor zero

adjustment is made with a screwdriver.

There is no need to break piping to

get at the top of the meter when

making this adjustment.

Reliable Gas MeasurementDown to 0 PSIGA unique dry snubber is standard on

Varea-Meters used for gas service.

It stabilizes the float, gives reliable

indication down to atmospheric

pressure for all meters 3/4 inch and

larger. (Smaller meters operate down

to 15 psig.) The dry snubber

eliminates dashpots, preserves the

straight through flow pattern.

Offset piping is not necessary.

GENERAL TECHNICAL DATAAccuracy2% of full scale with standard

calibration. Special calibration to

1% of full scale.

Range 10 to 1.

Dial Length 6 inches.

Dial UnitsPercent of maximum flow is standard.

Gpm water, scfm air, or special

graduations are optional.

Flange FacingsRaised face in ANSI 150°, 300° and

600 lb. flat face in ANSI 150° and

300 lb. Standard rating for large-

female face, tongue-and-groove face,

and ring-joint face is ANSI 600 lb.

These ANSI 600 lb. flanges are also

furnished to meet ANSI 300 lb. flange

requirements since all mating

dimensions, except flange thickness,

are identical for both.

Tongue-and-Grove FlangesMeters have groove (female) facings.

Either small or large grooves are

available.

Tube and Float MaterialsTube material 316 stainless steel. Float

316 stainless steel or Hastelloy C.

Write for CG 500.001, which is a

detailed listing of meter compatibility

with a wide range of fluids.

Flange MaterialsRaised face 150 lb. and 300 lb. in

carbon steel, 316 stainless steel.

All other facings available in 316

stainless steel only. (Extra low carbon

stainless steel available on meters with

150 lb. flanges only.)

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SELECTION PROCEDURE FOR LIQUID SERVICEDetermine the capacity range, temperature and pressure

capability, materials of construction, and options required

for each meter.

From chemical supplier determine float material. If the

liquid is other than water, the desired units are other than

GPM, its flow rate must be converted to GPM water

(equivalent Flow Rate).

How to Determine Water EquivalentFor liquids with viscosities greater than the viscosity ceiling,

Consult Distributor. For liquids with specific gravity other

than 1.0 follow the Formula to determine Equivalent Flow Rate

in GPM (QE).

Equivalent Desired CorrectionFlow Rate Flow Rate Factors

QE GPM QD FE X FU

1. From Table A determine FE from Specific

Gravity Correction factors.

2. From Table B determine FU from

Unit Conversation factors.

3. Work Formula to obtain Equivalent

Flow Rate (QE).

4. Use Equivalent Flow Rate to select tube

and float code from Table C on page 5.

=

=

X

X

SELECTION PROCEDURE

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SELECTION PROCEDURE FOR GAS SERVICEDetermine the capacity range, temperature and

pressure capability, materials of construction, and

options required for each meter.

From chemical supplier determine float material.

Table C capacities, are air SCFM at 14.7 PSIA & 70ºF.

If the gas is other than the above, its flow rate must

be converted to SCFM air (Equivalent Flow Rate)

How to Determine Air Equivalent1. From Table A select appropriate Formula to

determine Equivalent Flow Rate (QE).

2. From Table B determine FG from Specific

Gravity Correction factors.

3. From Table D determine FP from

Pressure Correction factors.

4. From Table E determine FT from

Temperature Correction factors.

5. From Table F determine FU from

Unit Conversion factors.

6. Work Formula to obtain Equivalent Flow Rate (QE)

7. Use Equivalent Flow Rate to select tube and float

code from Table C on page 5.

SELECTION PROCEDURE

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ORDERING PROCEDURE

METAL TUBE STRAIGHT-THROUGH VAREA-METERS

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TECHNICAL DATA

TEMPERATURE-PRESSURERATINGSWith 150 lb. ANSI flanges, all tube sizes:

230 psi at 0°F to 140 psi at 600°F

With 300 lb. ANSI flanges, all tube sizes:

600 psi at 0°F to 360 psi at 600°F

With 600 lb. ANSI flanges, 2-inch tube:

960 psi at 0°F to 620 psi at 600°F

With 600 lb. ANSI flanges, 11/2 inch

tube:

1200 psi at 0°F to 720 psi at 600°F

With 600 lb. ANSI flanges, 1/2, 3/4,

or 1 in. tube:

1200 psi at 0°F to 720 psi at 600°F

ELECTRONIC TRANSMITTERFEATURES Factory Mutual ApprovedOne transmitter model is Factory

Mutual approved as intrinsically safe for

hazardous loca-

tions. Another

model, in a haz-

ardous-service

arrangement, is

FM approved as

explosion proof. Both models are dust-

ignition proof.

Reliable Magnetic CouplingA powerful magnetic coupling exists

between the vertically moving float mag-

net and the rotation transmitter magnet.

There is only one possible position of the

transmitting mechanism for any float

position. Transmission and indication

are reliable, even under sudden flow

surges.

600ºF Operating TemperatureWhen used with an appropriate

Varea-Meter flow tube, these U.S.

Filter/Wallace & Tiernan Electronic

Transmitters handle process fluids to

600° F with no loss of accuracy.

Mounting on the meter tube leaves an

air space to impede heat transfer; heat

shields are not required. Careful selec-

tion of materials and non-lubricated

bearing throughout improve high-

temperature performance.

Separate Flow IndicationThe scale and pointer readout is

independent of the transmitting

mechanism. The pointer indicates

flow rate even if the transmitting

element is removed or if power fails.

Easy Addition in FieldAny model can be ordered mounted on a

new meter or can be easily added to an

already-installed meter. Field installation

does not require modification. removal,

or even recalibration of the meter. A

sliding internal bracket simplifies final

zero adjustment.

Design and OperationThe transmitter is a low energy, high

output load device. When used with an

approved energy-limiting barrier, it is

Factory Mutual approved as intrinsically

safe in hazardous locations*. Position of

the pointer and cam is achieved by a

powerful magnetic linkage to the float.

The cam has a captive follower which

positions the mechanical arm of a differ-

ential capacitance bridge sensor. Any

change in the bridge causes a proportion-

al change in the transmitter’s 4-20 mA

output and in the bridge feedback volt-

age. The change in feedback voltage is

used to rebalance the bridge. Zero and

span adjustment are included.

• For stand-by operation, the transmitter

is easily connected to operate from a

battery system.

• A gasketed NEMA 4 enclosure

protects the mechanism outdoors or

in dusty or corrosive atmosphere.

• The transmitter is easily wired to an

external stand-by battery.

Choice of ArrangementsThe transmitter is available in a

two-wire/four-wire general purpose

housing which when used with an

approved energy-limiting barrier, is

Factory Mutual approved as intrinsically

safe* for hazardous locations. It is also

available in an explosion proof* and

dust-ignition proof* arrangement. The

transmitter gives reliable linear flow-

proportional milliampere signals, but

other characterizations are available.

The transmitter is interchangeable with

any other readout and may be used with

a flow switch. Local readout is on a

6-inch scale; standard calibration is

percent of maximum flow. Calibration

in custom units is optional.

*As defined in Article 500, NEC.

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TECHNICAL DATA

AccuracyCombined meter and transmitter accura-

cy is 2% of full scale (1% with custom

calibration).

Sensitivity 0.2% of full scale.

Linearity 0.4% of full scale.

Repeatability 0.3% of full scale.

Operating Range 10 to 1.

Speed of ResponseComplete response to a flow-rate change

from 10% to 90% of full scale in 0.5

seconds.

Output Signals4-20 mA dc flow proportional.

Electrical RequirementsAvailable from U.S. Filter/Wallace &

Tiernan are: a 24 VDC supply for

general purpose, intrinsically safe (with

the appropriate electronic barriers), and

explosion proof arrangements. Current

Consumption: 5 mA signal current.

Allowable Loop Resistance0 ohms for 12 VDC supply, 500 ohms

for a 22 VDC supply (maximum allow-

able for intrinsically safe operation); 600

ohms for a 24 VDC supply; 900 ohms

for a 33 VDC supply.

Output Load EffectOutput independent of load.

Temperature RangeMaximum fluid temperature is 600°F;

ambient range is –13 to 140°F.

Temperature EffectOutput changes less than 0.036%

of full scale per degree F change

from – 13°F to 140°F.

Electrical ClassificationGeneral Purpose Enclosure: In NEMA 4

general purpose enclosure the transmitter

is Factory Mutual approved as intrinsi-

cally safe for Class I, Division 1, Group

A, B, C, and D hazardous locations

when installed according to instruction

book drawing 520.209.110.011.

FM entity parameters: Vmax = 30V;

Imax = 160 mA; Ci < 10 nF; Li =

50u H.

Examples of electronic barriers acceptable

under the entity system are:

Pepperl & Fuchs transmitter converter

KMD 2-cr-1.P.30300 or Zener barrier

#Z728 or Z828; MTL #706 + 20 and

FM approved as dust-ignition proof for

Class II, Division 1 and 2, Group E and

G and suitable for Class III, Division 1.

Optional Explosion proof Arrangement:

As an explosion proof arrangement, the

transmitter is FM approved as explosion

proof for Class I, Division 1, Group A,

B, C, and D hazardous locations; and

FM approved as dust-ignition proof for

Class II, Division 1, Group E, F and G

hazardous locations; suitable for Class

III, Division 1.

ConnectionsEnclosed 1/2" conduit connection.

Transmitter to receiver, unshielded wires.

FLOW SWITCHChoice of Two External AlarmsThis compact option gives reliable high

and /or low flow switching. The U.S.

Filter/Wallace & Tiernan Flow Switch

contains a powerful

rotating magnet

which responds lin-

early to float posi-

tion. Its switches

are long life, her-

metically sealed reed types. Almost

frictionless rotation of the switch magnet

and its powerful bond with the float

magnet give a dependable magnetic cou-

pling. Even under sudden flow surges

switching remains reliable. The switch is

available in a UL listed, hazardous loca-

tion* arrangement (Series 5500) and a

general purpose arrangement (Series

5600) in NEMA 4 enclosure.

Easily added in the field with the meter

in the line. No extension rod, on inter-

ference with vertical piping. Can set

switches to open or close on increasing

or decreasing flow. In the general pur-

pose model, this is done without remov-

ing the cover. A screwdriver adjustment

sets each switch independently over 0 to

100% of the flow range.

*As defined in Article 500, NEC.