Hydrodesulphurizer (HDS)


Customer had issues for many years with piping circuit including a small leakage resulting in an unplanned maintenance outage. Piping was eventually upgraded from carbon steel to stainless steel and various sections have been replaced multiple times. Large portion of line inaccessible requiring scaffolding or other access. Two units were installed at various points along piping circuit.


HDS – Temp ~160F (top), ~100F (bottom)

  • Four 3” elbows each w/ 2 duals (8 total)
  • One reducing tee w/ 2 duals
  • Four probes on “low spots” along circuit

Product Used

smartPIMS Cellular

  • smartPIMS LT Cellular (2) w/ 7 dual probes on each
  • Monitoring interval: 1 reading & transmission per day
  • Probes banded due to stainless steel piping
  • DSI bolted to walkway


  • Very low corrosion tolerance (Nom: .216”, Tmin: .154”) … ensured locations approaching minimum thickness would last until planned maintenance event