LPG & LNG Testing Services & Quality Assurance

Accredited LPG and LNG Testing Services in Houston, TX — propane and butane composition, vapor pressure, sulfur and H₂S speciation, and custody transfer compliance for gas distributors, terminals, and import facilities nationwide.

LPG & LNG Testing for Composition, Purity & Regulatory Compliance

AGT Labs provides professional LPG and LNG Testing Services to verify the composition, purity, and specification conformance of liquefied petroleum and natural gases. Our Houston laboratory delivers accredited analysis supporting custody transfer, cargo release, and compliance for distributors, terminals, and import/export operations.

Use the tabs below to view the full analytical scope, parameters, and standards for each product. LPG testing covers propane and butane composition, vapor pressure, and residue. LNG testing covers sulfur and H₂S contaminant limits critical for grid injection compliance.

Technical Stakeholders: LPG distributors verifying propane and butane grade, LNG terminal operators managing regasification sulfur limits, Pipeline operators confirming gas quality for grid injection, and Petrochemical facilities receiving liquefied gas feedstocks.

LPG Testing Services — Propane & Butane

Accredited composition, vapor pressure, residue, and corrosion testing for HD-5 propane, commercial butane, and autogas LPG grades per ASTM D2163, D1267, D2158, and D1838.

Accredited LPG Testing for Propane, Butane & Autogas Compliance

Our LPG Testing Services verify the quality and specification conformance of propane, butane, and LPG blends for distributors, cylinder bottlers, autogas suppliers, and petrochemical feedstock operations. Testing covers full hydrocarbon composition by GC (ASTM D2163), vapor pressure compliance, residue content, and copper strip corrosion — the four core requirements for LPG specification acceptance.

Key LPG Grades Tested: HD-5 Propane (GPA 2140 / ASTM D1835), Commercial Propane, Commercial Butane, Propane-Butane Blends, and Autogas LPG for vehicle fuel applications.

LPG Testing Services Highlights

  • Hydrocarbon Composition by GC — Propylene & Butylene Quantification (ASTM D2163)
  • Vapor Pressure — Reid Method Compliance (ASTM D1267)
  • Residue on Evaporation — Non-Volatile Matter & Oil Content (ASTM D2158)
  • Corrosiveness to Copper — LP Gas Strip Test (ASTM D1838)

LPG Key Technical Parameters

Accredited ASTM methods covering the core LPG specification requirements for propane, butane, and blend grade verification.

HC Composition (GC)
ASTM D2163
Vapor Pressure
ASTM D1267
Residue on Evaporation
ASTM D2158
Copper Corrosion
ASTM D1838
Propylene Content
ASTM D2163
Butylene Content
ASTM D2163

LPG Laboratory Capabilities

Analytical Systems

Our LPG Testing Services utilize GCFID systems configured for ASTM D2163 detailed hydrocarbon composition of liquefied petroleum gases and propane/propene mixtures. Vapor pressure is measured per ASTM D1267 and residue on evaporation per ASTM D2158 gravimetrically. Copper corrosion testing per ASTM D1838 is specifically validated for pressurized LP gas streams.

Technical Support

  • ISO/IEC 17025:2017 Accredited — PJLA Certificate No. L25-276
  • HD-5 Propane Full Specification Testing (ASTM D1835 / GPA 2140)
  • Rush Turnaround for Cargo & Terminal Release
  • Propylene & Butylene Quantification for Petrochemical Feedstock
GCFID instrumentation for LPG hydrocarbon composition analysis at AGT Labs Houston

LPG Quality & Reporting

COA reports from our LPG Testing Services provide defensible documentation for HD-5 specification acceptance, custody transfer, and commercial grade verification.

  • COA issued under ISO/IEC 17025:2017 accreditation (PJLA Cert. L25-276) with full ASTM method references.
  • ASTM D2163 results reported as full component breakdown — propane, butane, propylene, butylene.
  • Measurement uncertainty provided for vapor pressure and composition for custody transfer.
  • Technical consultation for out-of-spec propylene content or vapor pressure non-conformance.

LPG Standards

All LPG Testing Services are performed under PJLA ISO/IEC 17025:2017 accreditation (Certificate No. L25-276), valid through April 07, 2027.

ASTM D2163 ★
ASTM D1267 ★
ASTM D2158 ★
ASTM D1838 ★
ASTM D1835
GPA 2140

★ ISO/IEC 17025 Accredited — www.pjlabs.com

LNG Testing Services — Liquefied Natural Gas

Sulfur and H₂S contaminant analysis for LNG streams — critical for grid injection compliance, regasification terminal acceptance, and marine cargo quality documentation per ASTM D5504.

LNG Contaminant Testing for Grid Injection & Terminal Compliance

Our LNG Testing Services verify sulfur and hydrogen sulfide contaminant levels in liquefied natural gas streams to ensure compliance with pipeline injection specifications and terminal acceptance criteria. H₂S and total sulfur are the primary quality gatekeepers for LNG entering regasification facilities — elevated levels can damage infrastructure, violate grid tariff conditions, and create safety hazards.

AGT Labs performs sulfur speciation by PFPD-equipped gas chromatography per ASTM D5504, providing the precise contaminant data needed for cargo acceptance, dispute resolution, and operational compliance at import terminals and pipeline injection points.

Key LNG Applications: Regasification terminal cargo acceptance, Pipeline grid injection sulfur compliance, Marine cargo bill of lading quality documentation, and LNG-to-power facility contaminant screening.

LNG Testing Services Highlights

  • Total Sulfur & H₂S Speciation by GC/PFPD (ASTM D5504)
  • Hydrogen Sulfide — Pipeline Injection Compliance Threshold Verification
  • Carbonyl Sulfide (COS) & Mercaptan Quantification (ASTM D5504)
  • Results Issued Under ISO/IEC 17025:2017 Accreditation — PJLA Cert. L25-276

LNG Key Technical Parameters

Targeted contaminant analysis for LNG sulfur compliance — PFPD-equipped GC providing sub-ppm sensitivity across all sulfur species.

Total Sulfur
ASTM D5504
H₂S Content
ASTM D5504
Carbonyl Sulfide (COS)
ASTM D5504
Mercaptan Sulfur
ASTM D5504
Dimethyl Sulfide
ASTM D5504
Thiophene Content
ASTM D5504

LNG Laboratory Capabilities

Analytical Systems

Our LNG Testing Services utilize PFPD-equipped gas chromatography per ASTM D5504, providing compound-specific sulfur speciation at sub-ppm sensitivity. ASTM D5504 covers H₂S, COS, mercaptans, sulfides, and thiophenes in a single analytical run — delivering the complete sulfur profile required for pipeline injection compliance and terminal cargo acceptance.

Technical Support

  • ISO/IEC 17025:2017 Accredited — PJLA Certificate No. L25-276
  • Sub-ppm H₂S Detection for Strict Pipeline Threshold Compliance
  • Rush Turnaround for Marine Cargo & Terminal Release
  • Full ASTM D5504 Compound-Specific Sulfur Speciation Report
PFPD gas chromatography for LNG sulfur and H2S analysis at AGT Labs Houston

LNG Quality & Reporting

COA reports from our LNG Testing Services provide complete sulfur documentation for pipeline injection compliance, terminal cargo acceptance, and commercial arbitration.

  • COA issued under ISO/IEC 17025:2017 accreditation (PJLA Cert. L25-276) with full ASTM D5504 method reference.
  • Full compound-class sulfur speciation — H₂S, COS, mercaptans, sulfides, and thiophenes individually quantified.
  • Measurement uncertainty provided for H₂S and total sulfur results critical to pipeline injection threshold decisions.
  • Technical consultation for H₂S exceedance or total sulfur non-conformance ahead of grid injection.

LNG Standards

LNG sulfur testing is performed under PJLA ISO/IEC 17025:2017 accreditation (Certificate No. L25-276), valid through April 07, 2027.

ASTM D5504 ★
ISO 19739
GPA 2145
GPA 2261

★ ISO/IEC 17025 Accredited — www.pjlabs.com


Industries We Serve

Delivering accredited LPG and LNG analysis across the full gas supply chain — from production and marine transport to distribution, petrochemical feedstock, and grid injection compliance.

LPG Distributors & Bottlers

HD-5 propane and commercial butane grade verification for cylinder filling, autogas supply, and industrial bulk distribution operations.

LNG Import & Regasification Terminals

H₂S and total sulfur analysis for incoming LNG cargoes to confirm pipeline injection specification compliance and terminal acceptance.

Marine & Cargo Operations

Independent LPG and LNG cargo analysis for bill of lading compliance, custody transfer documentation, and ship/shore quality matching.

Petrochemical Feedstock

Propylene and butylene content verification in LPG streams supplied as cracker feedstock to petrochemical and refining operations.

Gas Pipeline Operators

Sulfur and H₂S contaminant testing to confirm LNG and LPG compliance with gas grid injection quality tariff requirements.

Refineries & Gas Processing

Quality control for LPG production streams and NGL fractionation to meet commercial specification for downstream sale and distribution.

Sampling, Handling & Chain of Custody

Both LPG and LNG sampling require specialized pressure-rated cylinders and strict handling procedures to prevent compositional changes before analysis. All samples must be accompanied by a completed Chain of Custody form.

Download Chain of Custody Form

LPG — Containers & Handling

  • Use DOT-approved, pressure-rated sample cylinders — never glass for pressurized LPG streams.
  • Fill cylinders to no more than 80% capacity to allow for thermal expansion during transport.
  • Purge cylinders thoroughly with sample gas before final collection to avoid air contamination affecting GC composition results.

LNG — Containers & Handling

  • LNG samples for ASTM D5504 sulfur analysis are collected as vapor-phase or gaseous samples using clean, inert-lined cylinders.
  • Avoid sample contact with reactive metal surfaces that could adsorb H₂S and cause low-bias sulfur results.
  • Record sampling pressure, temperature, and origin on the Chain of Custody form; ship via approved hazmat carrier.

Quality & Accreditation

All LPG and LNG Testing Services are performed under our ISO/IEC 17025:2017 accreditation issued by Perry Johnson Laboratory Accreditation, Inc. (PJLA), Certificate No. L25-276, valid through April 07, 2027.

Reporting Standards

Every Certificate of Analysis issued by AGT Labs meets the documentation requirements for custody transfer, commercial arbitration, and regulatory compliance.

  • COA issued under ISO/IEC 17025:2017 accreditation — fully traceable and legally defensible.
  • Full ASTM method references, numerical results, and measurement uncertainty on all reports.
  • Authorized laboratory signatory on all COAs for regulatory and commercial acceptance.
  • Split samples retained for re-test verification in custody transfer dispute scenarios.

Accredited Methods

Accreditation verified at www.pjlabs.com — Accreditation No. 118590.

ASTM D2163 ★ LPG
ASTM D1267 ★ LPG
ASTM D2158 ★ LPG
ASTM D1838 ★ LPG
ASTM D5504 ★ LNG

★ Confirmed on PJLA ISO/IEC 17025:2017 accreditation scope

Frequently Asked Questions

What is the difference between LPG and LNG testing?
LPG (propane and butane) is tested for hydrocarbon composition (ASTM D2163), vapor pressure (ASTM D1267), residue content (ASTM D2158), and corrosion (ASTM D1838) to verify grade specification. LNG testing focuses on sulfur and H₂S contaminant speciation by ASTM D5504 — the critical parameter for pipeline grid injection compliance and terminal acceptance.
What does HD-5 propane specification testing involve?
HD-5 is the highest commercial grade of propane per ASTM D1835 and GPA 2140. Testing requires minimum 90% propane content, propylene limited to 5% maximum, vapor pressure compliance (ASTM D1267), residue on evaporation (ASTM D2158), and a copper strip corrosion pass (ASTM D1838). All four core methods are accredited under our PJLA ISO/IEC 17025:2017 scope, Certificate No. L25-276.
Why is H₂S testing critical for LNG grid injection?
Hydrogen sulfide in LNG is toxic and corrosive to pipeline infrastructure, subject to strict tariff limits for gas grid injection. Exceedance can result in cargo rejection or pipeline damage claims. Our LNG Testing Services use ASTM D5504 PFPD gas chromatography to measure H₂S and all sulfur species at sub-ppm sensitivity, providing the precise contaminant data needed for terminal acceptance decisions.
How are LPG samples safely collected and shipped?
LPG samples must be collected into DOT-approved, pressure-rated sample cylinders, purged of air before filling, and filled to no more than 80% capacity. Shipping requires approved hazmat carrier documentation. Contact our Houston laboratory before shipping for specific cylinder and carrier requirements to ensure the sample arrives safely for accurate ASTM D2163 GC analysis.
Can AGT Labs provide testing for LPG or LNG custody transfer disputes?
Yes. As an ISO/IEC 17025 accredited laboratory (PJLA Certificate No. L25-276), our LPG and LNG Testing Services produce legally defensible Certificates of Analysis suitable for custody transfer disputes, contract compliance verification, and commercial arbitration. All results include full ASTM method references, measurement uncertainty, and authorized signatory. Split samples are retained for re-test verification when required.

Certify Your LPG & LNG with Accredited Testing Services

Need accredited LPG testing services for propane or butane grade verification, or LNG sulfur compliance analysis for your Houston terminal? Contact our technical team today for a custom quote.

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