SELECCIÓN DE CAUDALIMETROS

Tablas de Fabricantes

KEY

Best for this application

OK with some exceptions

OK for some applications but check first

Do not use in this service

Magnetic

Thermal Mass

Ultrasonic - Transit Time

Ultrasonic - Doppler

Vortex Shedding

Turbine

Variable Area

Postive Displacement

Differential Pressure

Página 1 de 1Flow Meter Selection Table

17/09/2007http://www.instrumart.com/Content.aspx?ContentID=219

Flowmeter Selection Guide

Fluid TypeTechnology Clean Dirty Viscous Pressure Max Temp Max Press Pipe Diam's Typical Typical Sizes

Liquid Liquid Liquid Slurry Gas Steam Loss F psi Req'd Turndown Accuracy inches NotesMagnetic None 450 750 10 30 to 1 .5% Rate .1 to 96 Fluid must be

conductiveCoriolis Medium 500 1500 None 40 to 1 .25% Rate .1 to 8 Very accurate,

MV, MassUltrasonic None 350 500 or 5 to 30 25 to 1 .75% Rate 1 + Fastest growing

pipe rat'g technologyVortex Low 450 1500 10 to 20 20 to 1 1% Rate 2 to 12 Great steam

flowmeterTurbine Low 500 3000 10 to 20 10 to 1 .5% Rate .25 to 24 Largest # of

meters soldDiff. Pressure Medium 750 3000 10 to 30 5 to 1 2% FS Any Orifice, Venturi,

Pitot, Flow elmt'sPos Displacement High 450 1500 None 15 to 1 .5% Rate .25 to 16 Oval, Piston,

Rotary VaneVariable Area Low 600 1500 None 10 to 1 2% FS 1/8 to 4 No power req'd,

Metal TubeOpen Channel Low 200 N/A None to 20 10 to 1 2% FS 2 + Plant effluent,

Flumes/WeirsThermal Low 500 1500 None to 30 30 to 1 1% FS 1/8 + Small MFC's to

large ducts

Intended ServicePossibly Applicable

Not Applicable

This guide represents an overview of flowmeter selection and a thorough evaluation of each application should be done to ensure proper selection.

Applied Engineering Inc203 Wylderose CourtMidlothian, VA 23113

804-378-3550

Flowmeter Selection Table Material Phase

Flowmeter Clean Liquid

Viscous Liquid Slurry Gas Solid Turndown

Pressure Loss

Upstream Straight Pipe Dia (Guide)

Downstream Straight Pipe Dia (Guide)

Typical Accruacy (% FSC)

Relative Cost Notes

Coriolis Y Y ? Y ? 20:1 H None None 0.5 M U' Tube are better than 'S' tube models but are however more

expensive.

Dall Tube Y ? ? Y N 3:1 M-H 15 5 1 H Similar to venturi but cheaper to manufacture.

Magnetic Y Y Y N N 10:1 N 5 3 2 H Must be conductive

Orifice Plate Y ? ? Y N 3:1 H 20 5 1 to 2 L Limitation of accuracy is due to

differential pressure sensing element.

Pitot Tube Y N ? Y N 3:1 M 30 5 1 to 5 L Pitot tube only provides point measurement of fluid flow in pipe.

Positive Displacement Y Y N Y N 10:1 H None None 1 On dirty duty filter

required. Turndown may be higher on Gas service.

Solids Flowmeter N N N N Y 20:1 NA NA NA 2 H Target Meter Y Y ? Y N 4:1 H 20 5 1 to 5 L Thermal Mass Flow Y ? ? Y N 20:1 M-H 5 3 1 M On dirty duty filter required.

Turbine Y ? N ? N 10:1 H 15 5 0.25 Maitnenance costs high due to need to overhaul.

Ultrasonic Y ? Y ? ? 10:1 N 15 5 2 to 3 M Cost depends on size? Clamp on meters difficult to get good / clean

pipe connection.

Variable Area Y ? ? Y N 5:1 M None None 5 to 10 L Generally these instruments provide local indication only.

Venturi Y ? ? Y N 3:1 M 15 5 0.5 to 1 H Limitation of accuracy is due to

differential pressure sensing element.

Vortex Y N N Y N 10:1 H 20 5 1 M Wier / Flumes Y ? ? N N 100:1 M See Link See Link 2-5% H Y- Yes H- High N- No M- Medium ?- Sometimes L- Low N- None

of Reynolds numbers (Re or RD) with-in which the various flowmeterdesigns can operate. In selecting theright flowmeter, one of the first stepsis to determine both the minimumand the maximum Reynolds numbersfor the application. Maximum RD isobtained by making the calculation

when flow and density are at theirmaximum and viscosity at its mini-mum. Conversely, the minimum RD isobtained by using minimum flow anddensity and maximum viscosity.

If acceptable metering performancecan be obtained from two differentflowmeter categories and one has

no moving parts, select the onewithout moving parts. Moving partsare a potential source of problems,not only for the obvious reasons ofwear, lubrication, and sensitivity tocoating, but also because movingparts require clearance spaces thatsometimes introduce “slippage” into

1 A Flow Measurement Orientation

TRANSACTIONS Volume 4 13

Orifice Square-Edged Honed Meter Run Integrated Segmental Wedge Eccentric Segmental V-Cone Target*** Venturi Flow Nozzle Low Loss Venturi Pitot Averaging Pitot Elbow Laminar

cP = centi Poise cS = centi Stokes SD = Some designs

? = Normally applicable (worth consideration) √ = Designed for this application (generally suitable)

URV = Upper Range Value X = Not applicable

‡ According to other sources, the minimum Reynolds number should be much higher

* Liquid must be electrically conductive ** Range 10:1 for laminar, and 15:1 for target *** Newer designs linearize the signal

Magnetic* Positive Displacement Gas Liquid Turbine Gas Liquid Ultrasonic Time of Flight Doppler Variable-Area (Rotameter) Vortex Shedding Vortex Precession (Swirl) Fluidic Oscillation (Coanda) Mass Coriolis Thermal Probe Solids Flowmeter Correlation Capacitance Ultrasonic

>1.5 (40) 0.5-1.5 (12-40) <0.5 (12) <12 (300) >2 (50) >4 (100) 0.5-72 (12-1800) <0.5(12) >2 (50) >2 (50) >3 (75) >3 (75) >1 (25) >2 (50) 0.25-16.6 (6-400) 0.1-72 (2.5-1800) <12 (300) <12 (300) 0.25-24 (6-600) 0.25-24 (6-600) >0.5 (12) >0.5 (12) ≤3 (75) 1.5-16 (40-400) <16 (400) >1.5 (40) 0.25-6 (6-150) <72 (1800) <24 (600) <8 (200) >0.5 (12)

RD > 10,000

RD > 10,000 RD > 10,000 RD > 500 RD > 10,000 RD > 10,000 RD : 8,000-5,000,000 RD > 100 RD > 75,000ŁRD > 50,000ŁRD > 12,800ŁRD > 100,000ŁRD > 40,000ŁRD > 10,000ŁRD < 500

700 (370)

150 (66)

≤600 (4,100)

≤30 (225) RD > 4,500

- No RD limit ≤ 8,000 cS - Rp > 5,000, ≤15 cS RD > 10,000 RD > 4,000 No RD limit, < 100 cS RD > 10,000, < 30 cP RD > 10,000, < 5 cP RD > 2,000, < 80 cS No RD limit No RD limit - No data available No data available

360 (180) 250 (120) 600 (315) -450-500 (268-260) -450-500 (268-260) -300-500 (-180-260) -300-500 (-180-260) 400 (200) 536 (280) 350 (175) -400-800 (-224-427) 1,500 (816) 750 (400) 300 (149) -300-250 (-180-120)

≤ 1,500 (10,800) ≤ 1,400 (10,000) ≤ 1,400 (10,000) ≤ 3,000 (21,000) ≤ 3,000 (21,000) Pipe rating Pipe rating ≤ 1,500 (10,500) Pipe rating ≤ 720 (5,000) ≤ 5,700 (39,900) Pipe rating ≤ 580 (4,000) ≤ 580 (4,000) Pipe rating

Proc

ess t

empe

ratu

re

to 10

00°F

(540

°C):

Tran

smitt

er li

mite

d to

-30-

250°

F (-3

0-12

0°C)

To 4

,000

psig

(4

1,000

kPa

)

Proc

ess t

empe

ratu

re

to 10

00°F

(540

°C):

Tran

smitt

er li

mite

d to

-30-

250°

F (-3

0-12

0°C)

To 4

,000

psig

(4

1,000

kPa

)

Glass: 400 (200) Metal: 1,000 (540)

Glass: 350 (2,400) Metal: 720 (5,000)

X

X X

SD X

X X ? √ √ X ? X X

X X

X

√ X

√ X

SD X √ √ √ X ? √ X

X X

X

X X

X X

SD X X ? ? X ? ? X

X X

X ? X

√ X

SD X X √ √ X

√ √ X

X X

X

√ X

√ X

SD X √ √ √ X

√ √ X

X X

√

X √

X √

√ X √ √ √ √

√ √ X

X X

?

X √

X X ? ? X X X X

√ ?

SD

√ ?

√

X ?

X ? ? ? ? ? ? X

√ √ X

√ √

√

X X

X X

X √ X ? X ?

√ √ ?

√ √

√

X ?

X ?

√ √ ? ? ? ? ? ? X

√ √

√

X X

X X

√ √ ? X X X ? ? X

√ √

√

X X

X X ? √ X X X X ? ?

SD

√ √

?

X X

X X

X X X X X X

X X √ ? X

?

X X

X X

X ? X X X X

√ ? X ? ?

?

X X ? ? ? X X X X X

X X X

X X

√

X X

X SD

? √ X X X X

√ ?

SD

√ √

√

X X

SD SD

√ √ X X X X ? X X

X X

√

X X

SD SD

√ √ ? X X ? ? ?

SD ? ?

?

X ? ? ?

X X ? ? ? ? ? ?

SD ? X

X

X X ? ? ? X ? ? X ? ? X X

X X

√ √ ? √ ? ? √ ? √ ? √ X √ X ?

√ √ √ √ ? ? √ √ √ √ √ √ √ √ √

X X X √ √ √ ? √ ? ? X X

SD ? X

√ √ √ √ √ √ √ √ √ √ √ √ √ √ √

√ √ √ √ √ √ √ √ √ √ √ √ √ √ √

√ √ √ √ ? ? √ √ √ √ √ √ √ √ √

X ? X ? X X ? ? ? X X X X X √

? ? ? √ ? ? √ √ √ ? ? ? ? ? ?

X X X ? ? ? ? √ ? ? X X

SD ? X

? ? ? ? ? ? ? ? ? ? √ ? ? ? ?

X X ? X X X X X X X X X X X X

X X X ? ? ? ? X √ X X X X X X

X X X ? X X ? X ? X X X X X X

SD SD SD SD SD SD X ? X X X X

SD √ X

? ? ? ? ? ? ? X ? ? ? X X X √

√ √ ? √ √ √ ? ? ? ? ? ? ? ? X

√ √ X √ √ √ ? ? ? ? ? ? ? ? X

X X X X X X X X X X X X X X X

? ? ? ? ? ? ? ? ? ? ? X X ? X

X X X X X X X X X X X X X X X

±1-4% URV ±1% URV ±2-5% URV ±0.5% URV ±2-4% URV ±2-4% URV ±0.5-1% of rate ±0.5-5% URV ±0.5-2% URV ±1-2% URV ±1.25% URV ±3-5% URV ±1-2% URV ±5-10% URV ±1% of rate

±0.5% of rate ±1% of rate ±0.5% of rate ±0.5% of rate ±0.5% of rate ±1% of rate to ±5% URV ±1% of rate to ±5% URV ±1% of rate to ±10% URV ±0.75-1.5% of rate ±0.5% of rate ±2% of rate ±0.15-10% of rate ±1-2% URV ±0.5% of rate to ±4% URV No data available ±6% of ??

FLOWMETER PIPE SIZE, in. (mm)

TYPICAL Accuracy, uncalibrated (Including transmitter)

TYPICAL Reynolds number ‡ or viscosity

TEMPERATURE °F (°C)

PRESSURE psig (kPa)

GASES (VAPORS)

LIQUIDS

PRES

S SL

URRI

ES

VISC

OUS

STEA

M

CLEA

N DI

RTY

HIGH

LO

W

CLEA

N HI

GH

LOW

DI

RTY

CORR

OSI

VE

VERY

CO

RRO

SIVE

FI

BRO

US

ABRA

SIVE

RE

VERS

E FLO

W

PULS

ATIN

G FL

OW

HIGH

TEM

PERA

TURE

CR

YOGE

NIC

SEM

I-FIL

LED

PIPE

S NO

N-NE

WTO

NIAN

S O

PEN

CHAN

NEL

Table 1: Flowmeter Evaluation Table

SQUARE ROOT SCALE: MAXIMUM SINGLE RANGE 4:1 (Typical)**

LINEAR SCALE TYPICAL RANGE 10:1 (Or better)

the flow being measured. Evenwith well maintained and calibratedmeters, this unmeasured flow varieswith changes in fluid viscosity andtemperature. Changes in temperature

also change the internal dimensions ofthe meter and require compensation.

Furthermore, if one can obtain thesame performance from both a fullflowmeter and a point sensor, it is

generally advisable to use theflowmeter. Because point sensors donot look at the full flow, they readaccurately only if they are inserted toa depth where the flow velocity is

A Flow Measurement Orientation 1

14 Volume 4 TRANSACTIONS

Orifice (plate or integral cell)

Segmental Wedge

V-Cone Flowmeter

Target Meters

Venturi Tubes

Flow Nozzles

Pitot Tubes

Elbow Taps

Laminar Flowmeters

Magnetic Flowmeters

Positive Displacement Gas Meters

Positive Displacement Liquid Meters

Turbine Flowmeters

Ultrasonic Flowmeters Time of Flight Doppler

Variable Area (Rotamater)

Vortex Shedding

Fluidic Oscillation (Coanda)

Mass Flowmeters Coriolis

Mass Flowmeters Thermal Probe

Solids Flowmeters

Weirs, Flumes

0.1

1.0

10

102

103

104

Solids Flow Units

105

106

0.1

1.0

10

102

103

104kgm/hr

Sm3/hr or Am3/hr

√

√

√ √

√

√

SD

√

√

√

√ √

SD

√

√

SD

√

√

√

√

√

√

√

√

√

H

A

M

M

M

A

M

N

H

N

M

A

A

N N

M

A

H

M/H

M

-

M

20/5

20/5

2/5

20/5

15/5

20/5

30/5

25/10

15/5

5/3

N

N

15/5

20/5 20/5

N

20/5

20/5

N

20/5

5/3

4/1

3:1

3:1

3:1 to 15:1

15:1

3:1

3:1

3:1

3:1

10:1

30:1

10:1 to 200:1

10:1

10:1

20:1 10:1

10:1

10/1

12/1

20:1

20:1

5:1 to 80:1

100:1

SR

SR

SR

SR

SR

SR

SR

SR

√

√

√

√

√

√ √

√

√

√

√

√

√

SD

H

M

A

H

H

M

M

N

M

H

N N

A

A

A

N

N

M

= Non-standard Range L = Limited SD = Some Designs H = High A = Average M = Minimal N = None SR = Square Root

➀ = The data in this column is for general guidance only. ➁ = Inherent rangeability of primary device is substantially greater than shown. Value used reflects limitations of differential pressure sensing device when 1% of rate accuracy is desired. With multiple-range intelligent transmitters, rangeability can reach 10:1. ➂ = Pipe size establishes the upper limit. ➃ = Practically unlimited with probe type design.

TYPE OF DESIGN

FLOW RANGE

DIRE

CT M

ASS-

FLOW

SENS

OR

DIFF

EREN

TIAL

PRE

SSUR

E-FL

OW SE

NSO

R

VOLU

ME D

ISPL

ACEM

ENT-

FLOW

SENS

OR

VELO

CITY

-FLO

W SE

NSO

R

EXPE

CTED

ERRO

R FR

OM

VIS

COSI

TY C

HANG

E

TRAN

SMIT

TER

AVAI

LABL

E

LINE

AR O

UTPU

T

RANG

EABI

LITY

PRES

SURE

LOSS

THR

U SE

NSO

R

APPR

OX. S

TRAI

GHT

PIPE

-RUN

REQ

UIRE

MEN

T (U

PSTR

EAM

DIA

M./

DOW

NSTR

EAM

DIA

M.)

Table 2: Orientation Table For Flow Sensors

√

√

√

√

√

√

√

√

√

√

SD

SD

√

√ √

√

√

√

√

√

√

√

10-6

10-5

Gas Flow Units

10-6

10-4

10-5

10-3

10-4

10-2

10-3

0.1

10-2

1.0

0.1

10

1.0

102

10

103

102

104

103

105

104

0.05

0.3

2.8

28.3

cc/min

.004

0.04

0.4

3.8

38

379

cc/min

m3/hr

gpm—m3/hr

SCFM—Sm3/hr

10-6

Liquid Flow Units

10-6

10-5

10-5

10-4

10-4

10-3

10-3

10-2

10-2

0.1

0.1

1.0

1.0

10

10

102

102

103

103

104

104

105

106

gpm

gpm—m3/hr

gpm—m3/hr

gpm—m3/hr

gpm—m3/hr

ACFM—Sm3/hr

gpm—m3/hr

SCFM—Sm3/hr

gpm—m3/hr

SCFM—Sm3/hr

gpm—m3/hr

SCFM—Sm3/hr

gpm—m3/hr

SCFM—Sm3/hr

gpm—m3/hr

SCFM—Sm3/hr

gpm—m3/hr

SCFM—Sm3/hr

gpm—m3/hr

SCFM—Sm3/hr

gpm—m3/hr

SCFM—Sm3/hr

gpm—m3/hr

ACFM—Sm3/hr

gpm—m3/hr

SCFM—Sm3/hr

gpm—m3/hr

lbm—kgm/hr

SCFM—Sm3/hr

lbm—kgm/hr

SCFM—Sm3/hr

➀➄

➁

➁

➁

➁

➁

➁

➁

➁

➆

➆

➆

➇

➅

➅

➈

➂

➂

➂

➂

➂

➃

➃

➄ = Varies with upstream disturbance. ➅ = Can be more with high Reynolds number services. ➆ = Up to 100:1. ➇ = More for gas turbine meters. ➈ = Higher and lower flow ranges may be available. Check several manufacturers.

General Guidelines for Flow Meter Selection

Flow Meter

Recommended Service

Turndown TypicalPressure

Loss

TypicalAccuracy

FS = Full Scale

Required Upstream

pipe, diameters

Effects from

changing viscosity?

Turbine Clean, viscous liquids 20 to 1 High +/- 0.25%

of rate 5 to 10 High

Positive Displacement

Clean, viscous liquids 10 to 1 High +/- 0.5%

of rate None High

Electromagnetic (Mag-Meter)

Clean, dirty, viscous,

conductive liquids and

slurries

40 to 1 None +/- 0.5% of rate 5 None

Variable Area (VA, Rota-

meter)

Clean, dirty, viscous liquids 10 to 1 Medium +/- 1 to

10% FS None Medium

Thermal Mass Flow (TMF)

Clean dirty viscous liquids some slurries

10 to 1 Low +/- 1% FS None None

Coriolis Mass Meter

Clean, dirty. viscous liquids, some slurries

10 to 1 Low +/- 0.5% of rate None None

Orifice Plate Clean, dirty, liquids some

slurries 4 to 1 Some +/- 2 to

4% FS 10 to 20 High

Pitot tube Clean liquids 3 to 1 Very low +/- 3 to 5% FS 20 to 30 Low

Ultrasonic (Doppler)

Dirty, viscous, liquids and

slurries 10 to 1 None +/- 5% FS 5 to 30 None

Ultrasonic (Transit Time)

Clean, viscous, liquids some dirty liquids

(depending on brand)

40 to 1 None +/- 1 to 3% FS 10 None

Venturi

Some slurries but clean, dirty and liquids with high viscosity

4 to 1 A little +/- 1% FS 5 to 18 High

Vortex Clean, dirty liquids 10 to 1 Medium +/- 1% of

rate 10 to 20 Medium