ASTM D4810-88(1999)
(Test Method)Standard Test Method for Hydrogen Sulfide in Natural Gas Using Length-of-Stain Detector Tubes
Standard Test Method for Hydrogen Sulfide in Natural Gas Using Length-of-Stain Detector Tubes
SCOPE
1.1 This test method covers a procedure for a rapid and simple field determination of hydrogen sulfide in natural gas pipelines. Available detector tubes provide a total measuring range of 0.5 ppm by volume up to 40% by volume, although the majority of applications will be on the lower end of this range (that is, under 120 ppm).
1.2 Typically, sulfur dioxide and mercaptans may cause positive interferences. In some cases, nitrogen dioxide can cause a negative interference. Most detector tubes will have a "precleanse" layer designed to remove certain interferences up to some maximum interferent level. Consult manufacturers' instructions for specific interference information.
1.3 The values stated in SI units are to be regarded as the standard.
1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 4810 – 88 (Reapproved 1999)
Standard Test Method for
Hydrogen Sulfide in Natural Gas Using Length-of-Stain
Detector Tubes
This standard is issued under the fixed designation D 4810; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope converted to ppm (by volume) hydrogen sulfide (H S), by
comparison to a calibration scale supplied by the manufacturer
1.1 This test method covers a procedure for a rapid and
for each box of detection tubes (higher range tubes have units
simple field determination of hydrogen sulfide in natural gas
of percent by volume). The system is direct reading, easily
pipelines. Available detector tubes provide a total measuring
portable,andcompletelysuitedtomakingrapidspotchecksfor
range of 0.5 ppm by volume up to 40 % by volume, although
hydrogen sulfide under field conditions.
the majority of applications will be on the lower end of this
range (that is, under 120 ppm).
4. Significance and Use
1.2 Typically, sulfur dioxide and mercaptans may cause
4.1 The measurement of hydrogen sulfide in natural gas is
positive interferences. In some cases, nitrogen dioxide can
important because of the gas quality specifications, the corro-
cause a negative interference. Most detector tubes will have a
sive nature of H S on pipeline materials, and the effects of H S
2 2
“precleanse” layer designed to remove certain interferences up
on utilization equipment.
to some maximum interferent level. Consult manufacturers’
4.2 This test method provides inexpensive field screening of
instructions for specific interference information.
hydrogensulfide.Thesystemdesignissuchthatitmaybeused
1.3 The values stated in SI units are to be regarded as the
by nontechnical personnel with a minimum of proper training.
standard.
1.4 This standard does not purport to address all of the
5. Apparatus
safety concerns, if any, associated with its use. It is the
5.1 Length-of-Stain Detector Tube and Calibration
responsibility of the user of this standard to establish appro-
Scale—A sealed glass tube with breakoff tips sized to fit the
priate safety and health practices and determine the applica-
tube holder of the pump. The reagent layer inside the tube,
bility of regulatory limitations prior to use.
typically a silica gel substrate coated with the active chemicals,
must be specific for hydrogen sulfide and must produce a
2. Referenced Documents
distinct color change when exposed to a sample of gas
2.1 Gas Processors Association Standard:
containing hydrogen sulfide. Any substances known to inter-
No. 2377-86 Test for Hydrogen Sulfide in Natural Gas
2 fere must be listed in the instructions accompanying the tubes.
Using Length of Stain Tubes
A calibration scale should be marked directly on the tube or
3. Summary of Test Method other markings which provide for easy interpretation of hydro-
gen sulfide content from a separate calibration scale supplied
3.1 The sample is drawn through a detector tube filled with
with the tubes. The calibration scale shall correlate hydrogen
a specially prepared chemical.Any hydrogen sulfide present in
sulfide concentration to the length of the color stain. Shelf life
the sampling reacts with the chemical to produce a color
of the detector tubes must be a minimum of two years from
changeorstain.Thelengthofthestainproducedinthedetector
date of manufacture when stored according to manufacturers’
tube, when exposed to a measured volume of sample, is
recommendations.
directly proportional to the amount of hydrogen sulfide present
5.2 Detector Tube Pump—A hand-operated pump of a
in the sample.Ahand-operated piston or bellows-type pump is
piston or bellows type. It must be capable of drawing 100 cm
used to draw a measured volume of sample through the tube at
per stroke of sample through the detector tube with a volume
a controlled rate of flow. The length of stain produced is
3 3
tolerance of 65cm . It must be specifically designed for use
with detector tubes.
NOTE 1—A detector tube and pump together form a unit and must be
This test method is under the jurisdiction ofASTM Committee D-3 on Gaseous
Fuels and is the direct responsibility of Subcommittee D03.05 on Determination of
Special Constituents of Gaseous Fuels.
Current edition approved April 29, 1988. Published June 1988.
2 3
Available from Gas Processors Association, 1812 First National Bank Bldg., Direct Reading Colorimetric Indicator Tubes Manual, 1st ed., American
Tulsa, OK 74103. Industrial Hygiene Association, Akron, OH 44311, 1976.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 4810
used as such. Each manufacturer calibrates detector tubes to match the
6. Procedure
flow characteristics of their specific pump. Crossing brands of pumps and
6.1 Select a sampling point that will provide access to a
tubes is not permitted, as considerable loss of system accuracy is likely to
representative sample of the gas to be tested (for example,
occur. (Note that at least one manufacturer allows extended samples up
to 100 pumpstrokes to obtain lower detection levels. This may be source valve on the main line). The sample point should be on
automated for screening purposes by drawing the sample from an inert
top of the pipeline and equipped with a stainless steel sample
collapsable container by vacuum displacement. The sample flow rate
probe extending into the middle third of the pipeline. Open the
should be maintained within 65 % of the manufacturer’s specified flow
source valve momentarily to clear the valve and connecting
rate. Accuracy losses are apt to occur in such special applications, and
nipple of foreign materials.
such a system is recommended only for screening purposes. Consult
6.2 Install needle valve (or pressure regulator) at the source
manufacturers regarding limitations.)
valve outlet. Connect sampling chamber using the shortest
5.3 Gas Sampling Chamber—Any container that provides
length of flexible tubing possible (Fig. 1). Avoid using tubing
for access of the detector tube into a uniform flow of sample
that reacts with or absorbs H S, such as copper or natural
gas at atmospheric pressure and isolates the sample from the
rubber. Use materials such as TFE-fluorocarbon, vinyl, poly-
surrounding atmosphere. A stainless steel needle valve (or
ethylene, or stainless steel.
pressure regulator) is placed between the source valve and the
6.3 Open source valve. Open needle valve enough to obtain
sampling chamber for the purpose of throttling the sample
positive flow of gas through chamber, in accordance with 5.3.
flow.Flowrateshouldapproximateonetotwovolumechanges
Purge the container for at least 3 min (Fig. 1).
per minute or, at minimum, provide positive exit gas flow
throughout the detector tube sampling period.
NOTE 4—If a collection bag is used instead of a sampling chamber,
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.