Many two component coatings use isocyanate in the hardener component. When changing drums, isocyanate forms sharp crystals on pump surfaces, damaging packings, and shortening pump life. IPM's OP-232C pump limits crystal formation to non-critical areas, allowing rods and packings to remain free of crystals, improving packing life. Quick release bung adapter provides fast drum changes, and hoses can remain attached, further limiting crystal formation. Improved construction features allow periodic cleaning of critical pump passages to provide virtually unlimited service life.