2 million SCFH / 720PSI Steam Sparged / Water Ballast Cryogenic Vaporizer LOX, LIN, LAR, LNG

What condition are the coil and shell in, and how would I verify that?

The listing does not describe current condition of the coil bundle (NB# 2643) or shell (NB# 1469). For a unit in mixed cryogenic service since 1999, you should request internal inspection reports or arrange hydrostatic testing, ultrasonic thickness mapping of the shell, and visual or eddy current examination of the coil tubes to assess remaining wall thickness, corrosion, and thermal cycling fatigue.

What should I check before putting a used steam vaporizer into service?

Verify current hydrostatic test certification and Code compliance for your jurisdiction, inspect coil integrity and shell thickness, confirm steam trap and pressure relief valve function, and check all instrumentation. Because this unit saw LOX service, ensure thorough cleaning and oxygen compatibility protocols if continuing oxygen use, or verify decontamination if switching services; mixed prior service (LOX, LIN, LAR, LNG) requires documenting the last fluid handled and cleaning history.