Transfer Pump Systems

Transfer pumps move chemical from the supply drums to the proportioner intake. They are a component that is sometimes overlooked in rig evaluation but is critical to reliable operation.

Function: Transfer pumps maintain a positive pressure feed to the proportioner intake, ensuring the machine receives a steady supply of material from the drums. Without proper feed pressure, the proportioner can experience cavitation or starvation — causing pressure variations and potentially off-ratio conditions.

Air-driven transfer pumps: Standard on most gas and diesel rig configurations. Use compressed air to drive chemical pumping. Require clean, regulated air at adequate pressure. Consume compressor CFM in addition to proportioner and gun demands.

Electric transfer pumps: Available on Elite-class proportioner platforms (Graco Core E1 and E2 systems). Use electric motors rather than compressed air. Reduce compressed air demand on the rig, which can improve proportioner performance on high-demand systems. The Graco Core E1 is standard on the E-30 Elite; Core E2 is standard on H-Elite platforms.

Pump maintenance: Transfer pumps require periodic packing inspection and replacement. Worn packing causes material leakage around the pump shaft. Pumps should be included in the regular rig maintenance schedule.

Logan Manifold systems: For rigs that switch between open-cell and closed-cell materials, a Logan Manifold provides controlled routing with air purge capability. This allows material changes without cross-contamination and purges transfer lines back to the drum at the end of a material run.