Hydro-Fluoric (HF) Alky Unit Monitoring


Customer was sending NDT technicians to inspect the top of the HF Alky unit daily to monitor specific low spots to ensure wall loss did not exceed minimum required rate before outage planned in 6 mo. Now using system to correlate corrosion data to integrity operating windows (IOWs).


HF Alky Unit (HF Isostripper OVHD elbow), ~150F

  • 24” Sch. 40 … most piping is < ½” nominal wall but measured at ~0.300” with pitting and general “low spots”

Product Used

smartPIMS Cellular

  • smartPIMS LT Cellular w/ 8 dual element probes temporarily attached, managed by refinery maintenance
  • Monitoring interval: 12 hours
  • Data is monitored & trended daily using webPIMS
  • Installation time: 4 hours


Objectives achieved:

  • Safety – kept personnel from climbing & cumbersome inspection positions on tower
  • Economic – saved >$365K in inspection cost
  • Easy to install/monitor, accurate & semi-permanent solution

Share this post

It’s All About the App

The UT transducer can enable and/or optimize the examination. This edition’s feature story includes solving an important application for an aerospace customer who wanted to

Read More »

3D CIVA Modeling

SNI combines two unique capabilities to help customers with difficult flaw detection and sizing inspections in heavy-wall forgings: CIVA 3D modeling + high-element-count 2D arrays.

Read More »
Sensor Networks, Inc.