Technical Resources — Pillar Hub for Standards, Calculators, and Engineering References
Pillar collecting all standards explainers, physics references, calculation walkthroughs, and engineering tools for sample probe assembly design and selection.
Engineering References for Sample Probe Design
This pillar consolidates every standards explainer, physics reference, and calculation walkthrough on the site. It is the canonical hub for the first-principles entities behind sample probe engineering.
Standards Explainers
| Standard | Hub Article |
| ASME PTC 19.3 TW-2016 | Wake Frequency Analysis |
| NACE MR0175 / ISO 15156 | NACE Sour Service Compliance |
| API 14.1 | Custody Transfer Sampling |
| GPA 2166 | Pipeline Sampling Best Practices |
| ISO 10715 | Natural Gas Sampling per ISO 10715 |
Physics & First Principles
- Reynolds, Strouhal, and the Physics of Vortex Shedding
- Barlow's Formula and Hoop Stress for Probe Tube Design
- Wake Frequency Analysis per ASME PTC 19.3
- Stainless vs PEEK in Harsh Chemistry (with Weber Number)
- Understanding Pressure Ratings and Barlow's Formula
Methodology Guides
- Isokinetic Sampling Theory and Probe Design
- Probe Cycle Life & Preventative Cleaning
- Time Delay in Online Process Analyzer Sampling
- Thermowell vs Sample Probe — Geometry & Standards
Material References
- Sample Probe Material Selection Guide
- Hastelloy C276 vs Inconel 625
- Chloride Pitting in 316L: Limits
- Tantalum & Zirconium for Extreme Acid Service
- SilcoNert Coatings for Trace Gas Analysis
Failure Modes
- Sulfide Stress Cracking in Sour Crude
- Hydrogen Embrittlement at High Pressure
- Wake Frequency / Vortex-Induced Vibration
- Probe Cycle Life Failure Modes
Adjacent Pillars
The Configurator
Every reference here is encoded as a validation rule inside the SPA Configurator. When a configuration violates any of the standards above, the configurator surfaces the specific clause and recommends a remediation path.
In This Cluster
Barlow's Formula and Hoop Stress for Sample Probe Tube Design
First-principles derivation of Barlow's formula for hoop stress in thin-walled probe tubes. Worked examples for 316L, Hastelloy C276, and Inconel 625 across the standard OD and wall thickness range.
Custody Transfer Sampling per API 14.1 and GPA 2166
Engineering and regulatory guide to custody transfer sampling of natural gas. API 14.1 spot, composite, and online sampling methodologies, GPA 2166 quality requirements, and probe design implications for fiscal metering.
Hastelloy C276 vs Inconel 625: Sample Probe Material Selection for Aggressive Service
Direct head-to-head comparison of Hastelloy C276 and Inconel 625 for sample probe assemblies. Pitting resistance equivalent (PREN), chloride limits, sour service compliance, weldability, and cost tradeoffs.
ISO 10715 Natural Gas Sampling: International Practice for Pipeline and Custody Sampling
Explainer on ISO 10715 — the international standard for natural gas sampling. Comparison with API 14.1 and GPA 2166, sample line design rules, probe requirements, and the dew-point trap problem.
Isokinetic Sampling: Theory, Probe Design, and When You Need It
Engineering guide to isokinetic sampling for particulate-laden gas and liquid streams. Theory, probe nozzle sizing, velocity matching, EPA Method 5, ASME PTC 38, and design tradeoffs.
NACE MR0175 / ISO 15156 Compliance for Sample Probes in Sour Service
How to specify NACE MR0175 / ISO 15156-compliant sample probe assemblies for H2S service. Material restrictions, hardness limits, heat treatment requirements, and the difference between MR0175 and MR0103.
The Definitive Guide to Probe Cycle Life and Preventative Cleaning
A complete engineering guide to sample probe cycle life: contact resistance drift, flux buildup, oxidation, tip punch-through, and a preventative cleaning schedule that extends mean-time-between-failure for industrial and clinical sampling probes.
Reynolds, Strouhal, and the Physics of Vortex Shedding for Sample Probes
First-principles guide to the dimensionless numbers that govern vortex-induced vibration of sample probe assemblies. Reynolds number flow regimes, Strouhal correlations, lock-in resonance, and Scruton number damping criteria.
Stainless Steel vs PEEK in Harsh Chemistry: Material Selection with the Weber Number
When PEEK beats 316L for chemical sampling and when 316L beats PEEK. Mechanical strength vs chemical inertness, the Weber number for atomization and droplet impact, and the role of biocompatibility.
Sulfide Stress Cracking in Sour Crude Sampling: Mechanism and Mitigation
How sulfide stress cracking destroys sample probes in sour crude and sour gas service. Mechanism, susceptible alloys, NACE MR0175 mitigation, and probe design choices that extend life in H2S-bearing streams.
Oil and Gas Pipeline Sampling Best Practices: Ensuring Representative Samples
Best practices for pipeline sampling in oil and gas applications, covering the center-third rule, probe orientation, retaining chains, sample conditioning, dead legs, and API 14.1 compliance.
Sample Probe Material Selection Guide: Choosing the Right Alloy for Your Process Conditions
A comprehensive guide to material selection for sample probe assemblies, covering 304 SS, 316 SS, 316L NACE, Monel 400, Hastelloy C-276, and Inconel 600 with temperature limits and application guidance.