How to source a hydraulic power unit?

Here's a step-by-step guide to sourcing hydraulic power units, distilled from industry experience:

1. Define Exact Specifications
Pressure/Flow Needs: List max pressure (PSI/bar) and flow rate (GPM/LPM) for all actuators. Include peak vs. sustained demands.
Duty Cycle: Specify operating hours (e.g., 24/7 continuous vs. 30-min bursts).
Environmental Limits: Note temperature extremes, dust, water exposure, noise restrictions.

2. Identify Supplier Types
OEMs (Eaton, Parker, Bosch Rexroth): For custom-engineered units with warranties.
Distributors (Sun Hydraulics, Hydac): For modified standard units; faster delivery.
Local Fabricators: Cost-effective for simple designs; vet quality rigorously.

3. Request Quotes Strategically
Demand Detailed Breakdowns:
Component brands (e.g., "R Component brands (e.g., "Rexroth A10VO pump, not generic")
Test certificates (pressure/flow validation)
Compliance docs (CE, ISO 4413)
Avoid "Catalog Engineering": Reject vague descriptions like "10 GPM unit."

4. Evaluate Proposals
Scrutinize Lead Times: Custom units take 8–12 weeks; verify material availability.
Compare Service Terms:
On-site support vs. return-to-depot repairs
Warranty exclusions (e.g., contamination damage voiding coverage)
Demand Failure Data: Ask for MTBF (mean time between failures) for pumps/valves.

5. Negotiate Smartly
Leverage Competitor Quotes: "Supplier X offers cast-iron pump at this price."
Push for Value Adds:
Free startup supervision
Extended filter warranties
Spare valve coils included

6. Audit Manufacturing (For Custom Units)
Visit Unannounced: Check:
Cleanliness of assembly area
Calibration tags on test equipment
Weld quality on reservoirs
Review QC Records: Demand hydraulic test charts showing pressure ripple.

7. Finalize Logistics
Incoterms Matter: FOB factory (you arrange shipping) vs. DDP (door delivery).
Pre-Install Checks:
Verify fluid compatibility
Confirm voltage/fuel type matches site
Check flange/port standards (SAE, DIN)

8. Post-Purchase Actions
Inspect on Delivery:
Damage to skids/hoses
Missing documentation (IOM manuals)
Test Under Load: Reject units that deviate >5% from quoted performance.