ASTM D3154-14(2023)
(Test Method)Standard Test Method for Average Velocity in a Duct (Pitot Tube Method)
Standard Test Method for Average Velocity in a Duct (Pitot Tube Method)
SIGNIFICANCE AND USE
5.1 The procedures presented in this test method are available, in part, in Test Methods D3685/D3685M, as well as the ASME Methods (PTC 19.10-1968, PTC 19.10-1981, and PTC 38-1980) given in 2.3 and Footnote 5,5 the 40 CFR Part 60 given in 2.4, and the publication given in Footnote 6.6
SCOPE
1.1 This test method describes measurement of the average velocity of a gas stream for the purpose of determining gas flow in a stack, duct, or flue. Although technically complex, it is generally considered the most accurate and often the only practical test method for taking velocity measurements.
1.2 This test method is suitable for measuring gas velocities above 3 m/s (10 ft/s).
1.3 This test method provides procedures for determining stack gas composition and moisture content.
1.4 The values stated in SI units are to be regarded as standard. The inch-pound units given in parentheses are for information only.
1.5 This test method is applicable to conditions where steady-state flow occurs, and for constant fluid conditions, where the direction of flow is normal to the face tube opening of the pitot tube employed in the method. The method cannot be used for direct measurement when cyclonic or swirling flow conditions are present.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D3154 − 14 (Reapproved 2023)
Standard Test Method for
Average Velocity in a Duct (Pitot Tube Method)
This standard is issued under the fixed designation D3154; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method describes measurement of the average
D1071 Test Methods for Volumetric Measurement of Gas-
velocity of a gas stream for the purpose of determining gas
eous Fuel Samples
flow in a stack, duct, or flue. Although technically complex, it
D1193 Specification for Reagent Water
is generally considered the most accurate and often the only
D1356 Terminology Relating to Sampling and Analysis of
practical test method for taking velocity measurements.
Atmospheres
1.2 This test method is suitable for measuring gas velocities
D3195 Practice for Rotameter Calibration
above 3 m/s (10 ft/s).
D3631 Test Methods for Measuring Surface Atmospheric
Pressure
1.3 This test method provides procedures for determining
D3685/D3685M Test Methods for Sampling and Determina-
stack gas composition and moisture content.
tion of Particulate Matter in Stack Gases
1.4 The values stated in SI units are to be regarded as D3796 Practice for Calibration of Type S Pitot Tubes
standard. The inch-pound units given in parentheses are for D6522 Test Method for Determination of Nitrogen Oxides,
information only. Carbon Monoxide, and Oxygen Concentrations in Emis-
sions from Natural Gas-Fired Reciprocating Engines,
1.5 This test method is applicable to conditions where
Combustion Turbines, Boilers, and Process Heaters Using
steady-state flow occurs, and for constant fluid conditions,
Portable Analyzers
where the direction of flow is normal to the face tube opening
E337 Test Method for Measuring Humidity with a Psy-
of the pitot tube employed in the method. The method cannot
chrometer (the Measurement of Wet- and Dry-Bulb Tem-
be used for direct measurement when cyclonic or swirling flow
peratures)
conditions are present.
E2251 Specification for Liquid-in-Glass ASTM Thermom-
eters with Low-Hazard Precision Liquids
1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
2.2 EPA Standards:
responsibility of the user of this standard to establish appro-
EPA-600/9-76-005 Quality Assurance Handbook for Air
priate safety, health, and environmental practices and deter- Pollution Measurement Systems. Vol I. Principles
mine the applicability of regulatory limitations prior to use.
EPA-600/4-77-027b Quality Assurance Handbook for Air
Pollution Measurement Systems. Vol III. Stationary
1.7 This international standard was developed in accor-
Source Specific Methods
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
2.3 ASME Performance Test Code Standards:
Development of International Standards, Guides and Recom-
PTC 19.10-1968 Flue and Exhaust Gas Analysis
mendations issued by the World Trade Organization Technical
PTC 19.10-1981 Part 10, Flue and Exhaust Measurements:
Barriers to Trade (TBT) Committee.
Instruments and Apparatus
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
1 3
This test method is under the jurisdiction of ASTM Committee D22 on Air Available from U.S. Government Printing Office, Superintendent of
Quality and is the direct responsibility of Subcommittee D22.03 on Ambient Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://
Atmospheres and Source Emissions. www.access.gpo.gov.
Current edition approved Jan. 1, 2023. Published February 2023. Originally Available from American Society of Mechanical Engineers (ASME), ASME
approved in 1972. Last previous edition approved in 2014 as D3154 – 14. DOI: International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
10.1520/D3154-14R23. www.asme.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3154 − 14 (2023)
PTC 38-1980 Determining the Concentration of Particulate
T = stack gas temperature, K (°R).
s
Matter in a Gas Stream
T = standard absolute temperature, 298 K
std
(528°R).
2.4 Code of Federal Regulation:
V = initial volume of condenser water, mL.
i
40 CFR Part 60 Standards of Performance for Stationary
V = final volume of condenser water, mL.
f
Sources, Appendix A1, Test Methods 1 through 4
V = volume of gas sample measured by the dry
m
3 3
gas meter, dm (dft ).
3. Terminology
v = stack gas velocity, m/s (ft/s).
s
3.1 Definitions:
V = volume of gas sample measured by the dry
m(std)
3.1.1 For definitions of terms used in this test method, refer
gas meter, corrected to standard conditions,
3 3
to Terminology D1356.
dm (dft ).
3.2 Descriptions of Symbols Specific to This Standard: V = volume of water vapor condensed, corrected
wc(std)
3 3
to standard conditions, sm (sft ).
2 2
A = cross-sectional area of stack, m (ft ).
V = volume of water vapor collected in silica gel,
wsg(std)
3 3
B = water vapor in the gas stream, proportion by
ws
corrected to standard conditions, sm (sft ).
volume.
W = final mass of silica gel or silica gel plus
f
C = pitot tube coefficient, dimensionless.
p
impinger, g.
D = internal diameter of stack, cm, (in.).
s
W = initial mass of silica gel or silica gel plus
i
K = pitot tube constant:
p
impinger, g.
1/2
g/g2mol
~ !
=
Y = dry gas meter calibration factor.
128.9 m/s (SI),
F G
~K!
0.28 = molecular weight of nitrogen or carbon
=
1/2
lb/lb 2 mol
~ !
monoxide, divided by 100.
85.49 ft/s
F G
~R!
0.32 = molecular weight of oxygen, divided by 100.
(inch-pound).
0.44 = molecular weight of carbon dioxide, divided
m = mean velocity, m/s (ft/s).
by 100.
M = molecular weight of stack gas, dry basis,
d
3600 = conversion factor, s/h.
g/g − mol (lb/lb − mol).
M = molecular weight of stack gas, wet basis,
s
4. Summary of Test Method
g/g − mol (lb/lb − mol).
4.1 This test method describes the use of instrumentation,
M = molecular weight of water, 18.0 g/g − mol
w
equipment, and operational procedures necessary for the mea-
(18.0 lb/lb − mol).
surement and calculation of the average velocity of air or gas
N = number of sampling points across a diam-
flows in flues, ducts, or stacks utilizing the pitot tube principle,
eter.
with a manometer or draft gauge for pressure measurement.
n = nth sampling point from center of stack.
The stack gas composition is determined, using either an Orsat
Δp = velocity head of stack gas, kPa (in. water).
analyzer, a Fyrite analyzer, or automated O and CO analyzers
P = static pressure of stack gas, kPa (in. water).
static 2 2
P = barometric pressure, kPa (in. Hg).
for determining diluent gas (O and CO ) concentrations, and
bar 2 2
P = absolute pressure at the dry gas meter (for
condensation techniques for determining the moisture content.
m
this test method it equals P ), kPa (in. Hg).
bar
5. Significance and Use
P = absolute stack gas pressure, kPa (mm Hg).
s
P = standard ambient atmospheric pressure,
std
5.1 The procedures presented in this test method are
101.3 kPa (760 mm Hg).
available, in part, in Test Methods D3685/D3685M, as well as
% CO = percent CO in the stack gas, by volume, dry
2 2
the ASME Methods (PTC 19.10-1968, PTC 19.10-1981, and
basis. 5
PTC 38-1980) given in 2.3 and Footnote 5, the 40 CFR Part
%(N + CO) = sum of the percents of N and CO in the
2 2
60 given in 2.4, and the publication given in Footnote 6.
stack gas, by volume, dry basis.
%O = percent O in the stack gas, by volume, dry
2 2 6. Apparatus
basis.
6.1 Pitot Tube, used in conjunction with a suitable
Q = dry volumetric stack gas flow rate corrected
std
3 3 manometer, provides the method for determining the velocity
to standard conditions, dsm /h (dsft /h).
in a duct. The construction of a standard pitot tube and the
R = ideal gas constant, 0.08312 (kPa) (m )/g −
method of connecting it to a draft gauge are shown in Fig. 1.
mol) (K) − (SI system) or 21.85 (in. Hg)
Details are shown in Fig. 2.
(ft )/(lb − mole) (°R) − (inch-pound).
6.1.1 To minimize the stem effect when the physical dimen-
r = radial distance from center of stack to nth
n
sions of the pitot tube are too large with respect to the flow
sampling point, cm (in.).
ρ = density of water, 0.9971 g/mL (0.002194
w
lb/mL) at 25 °C (77 °F).
Colen, P., Corey, R. C., and Meyers, J. W., “Methods and Instrumentation for
S = between laboratory bias, m/s (ft/s).
T Furnace Heat Absorption Studies; Temperature and Composition of Gases at
S = among single laboratory bias, m/s (ft/s). Furnace Outlets,” Transaction of the American Society of Mechanical Engineers,
s
Vol 71, pp. 965–78, 1949.
T = absolute average dry gas meter temperature,
m
Bulletin WP-50, Western Precipitation Division, Joy Manufacturing Co.,
K (°R).
“Methods for Determination of Velocity, Dust, and Mist Content of Gases.”
D3154 − 14 (2023)
6.6.2 Condenser—A water-cooled condenser that will not
remove O , CO , CO, and N , to remove excess moisture if the
2 2 2
gas stream contains over 2 % moisture by volume. The main
consideration is that the condenser volume be kept to the
minimum size because it will be more difficult to purge the
sample train before collecting a sample if the condenser is too
large. A 63-mm (0.25-in.) stainless steel coil, or equivalent,
connected to a water collection chamber with a capacity of
about 40 mL is sufficient.
FIG. 1 Pitot Tube
6.6.3 Valve—A needle valve to adjust the sample gas flow
rate.
6.6.4 Pump—A leak-free diaphragm pump, to transport the
scale, the diameter of the pitot tube barrel shall not exceed ⁄30 sample gas to the flexible bag. A small surge tank shall be
the size of the duct diameter. installed between the pump and the rate meter to eliminate the
6.1.2 At locations where the standard pitot tube cannot be pulsation effect of the pump on the rate meter. Leak-test the
pump, surge tank and rate meter (see 6.6.5), as described in
used in accordance with the sampling plan (see 8.1), or where
dust or moisture or both are present that may clog the small 9.4.3.
holes in this instrument, a calibrated Staubscheibe pitot tube, 6.6.5 Rate Meter—A rotameter or equivalent rate meter,
commonly called a Type “S” pitot tube, shown in Fig. 3, shall capable of measuring flow rates to within 62 % of the selected
be used. flow rate.
6.1.3 The Type “S” pitot tube may be used in all
6.6.6 Flexible Bag—A leak-free inert plastic bag, having the
applications, provided that it has been calibrated. See Practice
capacity adequate for the selected flow rate and length of time
D3796. However, use of the standard pitot tube, where
of the test. A capacity of 90 L (3.2 ft ) is usually sufficient. The
feasible, will give additional accuracy.
bag shall be leak-tested before each test, as described in 9.4.4.
6.6.7 Vacuum Gauge—An electronic manometer, or equiva-
6.2 Differential Pressure Gauge—A liquid-filled inclined
lent of 101.3 kPa (760 mm Hg) capacity, to be used for the
manometer or an equivalent device used to measure the
sample train leak test. Test the gauge as described in 9.4.6.
velocity head. See Fig. 1. It is equipped with a 250 mm (10 in.)
6.6.8 Diluent Gas Analyzer(s)—Automated gas analyzers or
water column inclined manometer that has 0.25 mm (0.01 in.)
an Orsat gas analyzer or Fyrite analyzer are used to analyze the
divisions on the 0-to-25 mm (1 in.) inclined scale, and 2.5 mm
gas sample for CO , and O , stack gas concentrations. The
(0.1 in.) divisions on the 25 to 250-mm (1 to 10-in.) vertical 2 2
Orsat analyzer (see Fig. 5) is operated by successively passing
scale. This type manometer (or other gauge of equivalent
the gas through adsorbents that remove the specific gaseous
sensitivity) is satisfactory for measurements of Δp values as
components. The difference in gas volumes before and after the
low as 12.5 Pa (0.05 in. H O).
absorptions represents the amount of constituent gas in the
6.3 Manometer—An electronic manometer or a water filled
sample. Separate Fyrite analyzers for measurement of CO and
U-tube manometer capable of measuring the stack or duct
O concentrations may be used to determine diluent gas
static pressures to within 0.33 kPa (2.5 mm Hg).
concentrations for some sources. Each Fyrite analyzer deter-
6.4 Thermocouple—A bimetallic device for measuring tem-
mines the difference in sample volume resulting from the
perature utilizing the fact that a small voltage is generated
absorption of the respective constituent gas in an appropriate
whenever two junctions of two dissimilar metals in an electric
absorbing solution. Do not use CO Fyrite analyzers at sources
circuit are at different temperature levels.
where effluent CO concentrations exceed 20 % such as
6.4.1 Potentiometer—An instrument for measuring small
mineral calciners.
voltages, or for comparing small voltages with a known
6.6.8.1 The analyzer shown in Fig. 5 includes a glass buret
voltage, used in conjuncture with the thermocouple. Alterna-
to measure the gas volume of the sample, a water jacket to
tive thermocouple read-out devices capable of accurately
maintain constant temperature, a manifold to control the gas
measuring the effluent gas temperature to within 2 °C may be
flow, two or three absorption pipets (to remove CO , and O , as
2 2
used.
well as CO at the option of the user), rubber expansion bags,
6.4.2 Thermometer—A precision digital thermometer based
and a liquid-filled leveling bottle to move the gas sample
on resistance temperature detectors (RTDs), thermistors,
within the analyzer.
thermocouples, or organic liquid-in-glass thermometers (such
6.6.8.2 For CO values >4 %, a standard Orsat gas analyzer
as Thermometer S18C in Specification E2251) meeting the
with a buret with 0.2 mL divisions and spacings divisions of
requirements of this application may be used.
about 1 mm (0.14 in.) is satisfactory. For lower CO values or
for O values >15 %, a buret with 0.1 mL divisions with
6.5 Barometer—An instrument capable of measuring ambi- 2
spacings of >1 mm shall be used.
ent atmospheric pressure to 0.5 kPa. See Test Methods D3631.
6.6.8.3 The analyzer shall be leak-tested before and a
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