When sourcing a multistage jockey pump, the most critical factors are Pressure Rating (Head) and Flow Rate. Since these pumps maintain pressure in fire protection systems, ensure the shut-off head is higher than the main fire pump's pressure switch setting. Material construction is equally vital; prioritize Stainless Steel (AISI 304 or 316) impellers and chambers to prevent corrosion during long periods of inactivity. Additionally, verify the Mechanical Seal quality (e.g., Carbon/Ceramic/EPDM) to ensure leak-free operation under high-pressure cycles.