ASTM D5705 is the Standard Test Method for Measurement of Hydrogen Sulfide ( H2Scap H sub 2 cap S ) in the Vapor Phase Above Residual Fuel Oils . It is a field determination method used primarily for safety and quality control to identify hazardous H2Scap H sub 2 cap S levels in the headspace of storage tanks or containers. Core Method Details Purpose: Measures H2Scap H sub 2 cap S concentration in the equilibrium headspace (vapor phase) rather than the liquid phase. Applicability: Designed for residual fuel oils (ASTM D396 Grade Nos. 4, 5 Heavy, and 6) with viscosities between 5.5 at 40°C and 50 at 100°C. Typical Range: Measures vapor-phase concentrations from approximately 5 to 4000 ppm H2Scap H sub 2 cap S Procedural Overview The test, often called the "Can Test," involves specific steps to create an equilibrium between the liquid fuel and the vapor: Preparation: A 1-liter H2Scap H sub 2 cap S -inert glass test bottle is filled 50% with the fuel oil sample. Agitation & Heating: The sample is heated and shaken as described in the standard to generate a representative vapor headspace. Measurement: A lead acetate-filled gas detection tube (e.g., a Draeger tube) is used to measure the gas concentration in the vapor space. Limitations and Alternatives Precision: This method is effective for identifying the presence of H2Scap H sub 2 cap S but is considered less precise for exact quantification. Staining of the detection tubes can sometimes lead to misinterpretation. Related Standards: ASTM D7621 : Uses rapid liquid phase extraction for more precise liquid-phase H2Scap H sub 2 cap S determination. ASTM D6021 : Involves multiple headspace extraction and sulfur-specific detection. Official Resources The full standard is a copyrighted document and must be purchased for complete procedural steps, safety requirements, and precision data:
ASTM D5705, often called the "Can Test," is the industry standard for measuring hydrogen sulfide (H₂S) in the vapor phase above residual fuel oils. This method is utilized for field-portable, rapid assessments of H₂S levels ranging from 5 ppm to 4000 ppm, essential for safety in marine transport and terminal storage. Read the full technical standard details via the ASTM D5705-2015 PDF .
ASTM D5705 is a standard test method specifically designed for the field measurement of hydrogen sulfide ( cap H sub 2 cap S in the vapor phase above residual fuel oils. It is widely used by refiners and terminal operators to ensure safety and quality control during the handling of bunker fuels. ASTM International Report Overview: ASTM D5705 Standard This test method provides a rapid, cost-effective way to estimate the cap H sub 2 cap S hazard in a fuel tank's headspace without complex laboratory equipment. Scope & Application : Applicable to residual fuel oils (Grade Nos. 4, 5, and 6) with a viscosity range of 40 raised to the composed with power C 100 raised to the composed with power C Measurement Range : Typically covers cap H sub 2 cap S concentrations from 5 to 4000 ppm v/v (parts per million by volume). Testing Principle : The method involves agitating a fuel sample in a closed vessel and measuring the gas concentration in the headspace using a lead acetate-filled gas detection tube (often referred to as a Draeger tube). ASTM International Key Technical Specifications Standard Designation ASTM D5705-20 (Current Version) Target Analyte Hydrogen Sulfide ( cap H sub 2 cap S Phase Tested Vapor phase (equilibrium headspace) Primary Tool Length-of-stain gas detector tubes Volume Required Sample container is partially filled to create headspace Comparison with Related Methods While ASTM D5705 is a field-friendly vapor test, it is often used alongside other standards for more comprehensive analysis: ASTM D7621 : Measures cap H sub 2 cap S liquid phase using rapid extraction, offering higher precision for product quality. ASTM D6021 : A more detailed analytical method for liquid-phase cap H sub 2 cap S using headspace gas chromatography. Safety Warning cap H sub 2 cap S is highly toxic; testing should always be conducted in well-ventilated areas or under a when possible. ASTM International Where to Access The full standard and technical reports are available through official providers: Official Standard : Purchase the active ASTM D5705 PDF directly from ASTM International Redline Versions Redline PDF is available for comparing changes between the current and previous versions (e.g., 2015 vs. 2020). Historical Records : Earlier iterations like can be found in the ASTM digital library for legacy compliance. ASTM International
Title: An Overview of ASTM D5705: Standard Test Method for Measurement of Hydrogen Sulfide in the Headspace of Crude Oil Introduction ASTM D5705 is a standard test method developed by ASTM International. It is specifically designed to quantify the concentration of hydrogen sulfide (H₂S) in the vapor phase (headspace) of crude oil samples. As H₂S is a highly toxic and corrosive gas, accurate measurement is critical for refining, transportation safety, and regulatory compliance. While the full standard is available as a PDF purchase from ASTM, this informative text summarizes the scope, procedure, and significance of the method. 1. Scope and Application The primary purpose of ASTM D5705 is to determine the vapor phase concentration of hydrogen sulfide (H₂S) in crude oil. This is distinct from measuring total sulfur content; this test specifically looks at the dangerous gas that accumulates in the air space above the liquid oil. astm d5705 pdf
Typical Range: The method is generally applicable for measuring H₂S concentrations ranging from 0.01 mg/L to 100 mg/L in the headspace. Relevance: It is widely used in the petroleum industry to assess the "sourness" of crude oil. High H₂S levels require specific handling protocols, material selection (to prevent corrosion), and safety measures for personnel.
2. Significance and Use
Safety: H₂S is lethal at high concentrations. Knowing the headspace concentration helps facilities determine the Personal Protective Equipment (PPE) required for workers opening tanks or sampling. Corrosion Prevention: H₂S causes sulfide stress cracking and corrosion in pipelines and storage tanks. Refineries often set strict limits on H₂S content in crude oil received. Regulatory Compliance: The data helps companies comply with occupational safety regulations (such as OSHA) and environmental standards regarding emissions. ASTM D5705 is the Standard Test Method for
3. Summary of the Test Method The procedure involves creating a controlled equilibrium between the liquid crude oil and the gas above it, followed by chemical detection.
Sample Preparation: A representative sample of crude oil is placed in a specialized container. It is vital that the sample is not agitated excessively, as this can artificially inflate H₂S readings. Headspace Development: The container is typically shaken or rotated to allow the liquid and gas phases to reach equilibrium at a controlled temperature. Measurement (Detector Tube Method): The most common procedure described in earlier versions of the standard involves drawing a specific volume of the headspace gas through a glass detector tube. These tubes contain a chemical reagent that changes color in the presence of H₂S. The length of the color stain corresponds to the concentration. Alternative Instrumentation: Modern applications often utilize portable gas chromatography or electronic H₂S analyzers for higher precision, though the chemical tube method remains the standard reference for field operations.
4. Interferences and Limitations When reviewing the ASTM D5705 PDF, users will find specific sections on interferences. Applicability: Designed for residual fuel oils (ASTM D396
Other Sulfur Compounds: Other sulfur species (like mercaptans) may interfere with the chemical reaction in detector tubes, potentially leading to inaccurate readings. Temperature: H₂S solubility in crude oil is temperature-dependent. The standard specifies strict temperature controls because readings can fluctuate significantly if the oil is hot versus cold. Vapor Pressure: Crude oils with very high vapor pressures may present challenges during sampling, potentially forcing gas out of the cylinder before analysis.
5. The Importance of the ASTM D5705 PDF The official PDF document is essential for laboratory personnel because it provides: