Complying with PHMSA Mega Rule, Analyzing Residuals in Steels and L-grade Stainless
February 19, 2021
Measure carbon equivalents for weld analysis with a handheld analyzer
Handheld LIBS helps pipeline operators comply with the PHMSA "Mega Rule."
Downstream refiners can now verify carbon and residual metal content in steels for HF Alkylation units for API 751.
SciAps Z-902 Carbon measures carbon and carbon equivalents for in-field pipeline materials, steels and welds in seconds.
The next-generation handheld laser analyzer weighs < 4 lbs., battery included, that measures carbon content, silicon, and a range of metals in steels, stainless and other alloys in a few seconds. Specific to PHMSA and general pipeline requirements, the SciAps Z-902 Carbon provides carbon content, carbon equivalents (CE), and concentrations of alloying elements Si, Ti, V, Mn, Cr, Cu, Ni, Nb, Mo and other elements. Based on industry input, a dedicated Pipeline App automates the industry’s testing methodology to reduce operator error. It is used for carbon and CE work, especially for American Petroleum Institute (API) specification 5L.
SciAps Z Series is widely accepted by most major pipeline owner/operators or their NDT contractors as an alternative to spark OES testing or off-site laboratory results. There are hundreds of SciAps Z units in the field daily for pipeline analysis. Included with the analyzer is a recommended testing procedure that incorporates sample preparation and certified reference materials for quality assurance validation.
Further downstream, the Z delivers a handheld solution for various PMI applications that require carbon measurement. These include residuals testing, where carbon content can be verified above or below 0.18% and CE measured, and also for carbon content in stainless for L- or H-grade verification.
The available Pipeline App automates recommended testing procedures, including test averaging, quality assurance and calibration checks. A primary goal is to encourage uniform testing and data validation across a spectrum of analyzer users to improve overall data quality. Also included with the Pipeline App are specific type standardization materials. For example, the procedure adopted by most pipeline owner/operators requires the analyzer operator to switch to a type standardization if the CE is in the critical range of 0.4 – 0.5, because of hydrogen cracking concerns. The type standardization “dials in” the carbon and CE calibrations in this critical range to yield even greater accuracy. The Z operates on the Android platform making it easy to add new applications as they become available.
Likewise, the Residuals App includes quality-control check standards and tighter calibrations to “dial in” the carbon calibration for steels around the 0.18% level. It also automatically calculates the sum of Cr, Cu and Ni, or just Cu and Ni (if C > 0.18%) and Nb + V compared to the limits of 0.15 and 0.03, respectively.
How does it work?
SciAps Z-902 Carbon utilizes the technique of laser induced breakdown spectroscopy (LIBS). That's fancy language for "shoot a laser at the metal, vaporize it and measure the light emitted." The emitted light reveals elements present and how much of each.
LIBS is an optical emission technique like spark OES. But with LIBS, the high voltage spark source is replaced by a miniature, pulsed laser. Although battery powered, the pulsed laser is energetic enough to vaporize the metal being analyzed.
And because the SciAps Z laser is very focused (less than 100 um), the volume required for argon purge is much smaller—up to 1,000 times smaller—so argon consumption is much lower. In addition, the argon flow is automatically cycled off between tests. The Z delivers about 150 carbon, CE results in a single, user-replaceable argon canister located within the device. They cost about $7.50/canister, or about 5 cents/test.
Independent industry studies have shown that carbon and CE testing with the SciAps Z is up to 3x faster than traditional spark OES testing. That's largely due to the fact that operators can perform in-ditch testing without having to move large tanks of compressed argon gas, re-purge and/or recalibrate the analyzer.
Did you know?
SciAps also makes a leading handheld XRF analyzer for PMI. While it doesn’t measure carbon (only LIBS or spark OES can do that), it does provide fast, precise results for phosphorus (P), sulfur (S) and transition and heavy metals. Together, SciAps provides the industry-leading combination of XRF and LIBS: A compact, affordable package with shared accessories like batteries, charger and cables. Optimal performance for virtually every alloy and element for less money than a comparable spark OES system.