ERVW® AOD Piping Calibration Blocks with Side-Drilled Holes

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PH Tool and Holloway NDT have jointly designed and produced a set of three Extended Range Variable Wall (ERVW)® Piping Calibration Blocks (US Patent No. US D881,728 S, dated April 21, 2020.)

Created for calibration in the axial direction for examination of circumferential butt welds, these blocks come in three sizes: small (3” to 5”), medium (6” to 10”) and large (12” to 20”). These blocks range from 3 to 20 pounds and 7 to 16 inches, making them lightweight and portable. 

The key to the Extended Range Variable Wall series is the "variable" aspect. Only three blocks are needed to cover a large range of pipe sizes, which would otherwise require dozens of calibration blocks. The small block covers 12 pipe sizes, while the medium block covers 29 sizes. The large size covers a massive 55 inspection sizes on the pipe schedule chart. See the chart above for more information about which ERVW Piping Calibration Block can be used with which pipe sizes. Each step is also engraved with the pipe sizes (OD/wall) covered.

(ERVW ™) Extended Range Variable Wall ™ Piping Calibration Blocks Size

The ERVW blocks feature side drilled holes in accordance with T-434.3-2 for testing circumferential pipe welds. The slanted end cut eliminates corner trap reflections and allows for full DAC/TCG calibrations with conventional ultrasonic testing or phased-array ultrasonic testing. Machine-engraved transducer positioning marks aid in functionality and maximize your signal from the SDHs. Each block is machine-engraved with a unique serial number and alloy. The surface finish is media-blasted to 125 Ra max to simulate inspection conditions.  The steps were placed on the ID rather than the OD to maximize usefulness of wedge curvature in accordance with the requirements of T-432.2 introduced in 2017. 


ERVW Sets containing EDM notches ARE NOW AVAILABLE.  Follow the link to learn more. 

The ERVW Piping Calibration Blocks are now being offered in steel and stainless steel. Sets of blocks for circumferential scanning on long seam welds ARE NOW AVAILABLE for purchase as well. 

Don't need the whole set of three blocks? No problem; we now offer the ERVW blocks as Singles. Simply specify if you need the Small, Medium, or Large block. 

If you have questions about our Extended Range Variable Wall (ERVW) Piping Calibration Blocks or would like to place an order, please contact us for a quote.