4,500 PSI 6000 SCFH N2 Vaporizer

Is this sized for my peak demand or my average?

Ambient vaporizers are typically sized for peak demand with a safety factor, not average flow, because they have limited thermal mass and cannot handle sustained overcapacity without frost formation choking the coils. This unit is rated at 6,000 SCFH N2. If your peak instantaneous demand exceeds that, you'll see performance degradation; if your average is well below it, the unit will cycle as needed without issue.

What gases can it be put into service with, given what it ran before?

This is new equipment per the listing, so there is no previous service history to constrain gas compatibility. Vaporizers built for nitrogen service are generally suitable for argon, helium, and other inert cryogenic gases, but oxygen service requires units specifically cleaned and certified for oxygen (typically denoted in the model number or documentation). Confirm with the seller what oxygen cleaning or material certifications apply if you're considering anything beyond nitrogen or inert gas use.

What are the installation and utility requirements?

The unit measures 45" x 45" x 98", so plan for an 8-foot vertical clearance and a footprint just under 4 feet square. Ambient vaporizers require no electrical or fuel utilities but do need adequate airflow around the fins; restricted ventilation or recirculating warm exhaust air will reduce capacity, especially during high-demand periods. The listing does not specify inlet/outlet connection sizes beyond the model designation, so confirm flange or NPT fittings and orientation with the seller.

What should I inspect on a used vaporizer before buying?

This unit is listed as new, not used, so the typical used-equipment inspection concerns (fin corrosion, evidence of overpressure, weld integrity around headers, and hydro test currency) should not apply. For new equipment, verify that the hydro test documentation matches the serial numbers listed (99853, 99854, 99855, 99856, 99857) and that the test pressure of 6,750 PSI meets code requirements for the 4,500 PSIG design rating. Confirm which of the five serial numbers corresponds to which physical unit if you're purchasing fewer than all listed.