CS & P Duplex — 7 GPM Hydraulic Engine-Driven LN2 Pump

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

This unit is rated for 7 GPM output. Head and NPSH requirements are not specified in the listing; ask the seller for the performance curve and minimum required NPSH at rated flow. Cryogenic pumps typically require 5-15 psi NPSH depending on flow rate and impeller design, and duplex configurations like this often serve applications requiring either redundancy or staged pressure.

What seals, materials and drive does it have?

The unit has engine-driven hydraulic operation with dual 1.25-inch capacity, but specific seal type and wetted materials are not listed. CS & P cryogenic pumps typically use stainless steel construction with elastomer or mechanical seals rated for LN2 service; confirm seal configuration, whether the hydraulic drive includes its own power unit, and materials of construction with the seller.

What should I inspect on a used pump before buying?

Check the pump heads for freeze damage, inspect seals for cracking or compression set, and verify hydraulic system operation including valve function and cylinder condition. On duplex systems, test both pumps independently, check for cross-contamination in the hydraulic fluid, examine all cryogenic piping and fittings for damage, and verify the engine or hydraulic power unit starts and holds pressure. If condition is unknown as stated here, budget for seal replacement and a full hydraulic service at minimum.