Nikkiso - ACD 1 SGV Cryogenic Pump (New/ Never Used), 7000 psi, 3.1 GPM Flow, 40HP Liquid Hydrogen LH2, LIN, LAR

What flow and head is this rated for, and at what NPSH?

This unit is rated for 3 GPM average flow at a maximum working pressure of 7,000 psi, with an NPSH requirement (listed as NPSPR) of 10 psi. The listing notes that actual flow can be higher depending on discharge pressure, and refers to the attached manual for detailed performance curves. Reciprocating cryogenic pumps typically show significant flow variation with stroke speed and discharge pressure, so consult the manufacturer's curve for your specific operating point.

What service has it been in, and what were the running hours?

This pump is new and has never been used. It was originally built for liquid hydrogen service and has been stored in its original packaging in a warehouse for several years. Zero running hours.

What seals, materials and drive does it have?

The listing specifies a 40 HP explosion-proof motor driving at 1,760 RPM through what is typically a gearbox or belt reduction to achieve the 499 RPM pump speed, with a 1.25" bore and 1.38" stroke single-piston design. Specific seal materials and wetted metallurgy are not stated in the listing—ask the seller for the material certification and seal package details, as these are critical for hydrogen compatibility and differ significantly from nitrogen or argon configurations.

What should I inspect on a used pump before buying?

Since this unit is new and unused, the primary concerns are storage-related rather than wear: verify seals and gaskets haven't degraded during the multi-year warehouse period, confirm the motor windings test correctly for insulation resistance, and check that no moisture has entered the pump or cold end. On any reciprocating cryogenic pump, whether new or used, inspect piston/cylinder wear surfaces, check valve seats, seal condition, and verify the crankcase oil is clean—though with zero hours, this unit should show factory-fresh surfaces throughout.