Dispensing, matched to the ratio — not the catalog page

Metered dispensing systems (like Graco's sealant/adhesive lines) control the exact ratio and volume dispensed per cycle, which matters for two-part adhesives/sealants where an incorrect mix ratio compromises cure and bond strength — a distinction that matters more as batch consistency requirements tighten.

Yes — the pump, seals, and fluid path materials need to be confirmed compatible with the specific adhesive/sealant chemistry (solvent-based, moisture-cure, two-part epoxy, etc.), the same Material Specification discipline applied to any wetted chemical equipment, not assumed from general-purpose dispensing equipment marketing.

Common causes include worn metering components, incorrect pressure setting for the fluid's viscosity, or air entrainment in the fluid path — flow verification instrumentation on a dispensing system can catch a dosing drift before it produces out-of-spec product, rather than discovering it after the fact.

No — real selection also depends on the fluid's cure mechanism (time-sensitive pot life for two-part systems), required dispense volume accuracy, and duty cycle, in addition to viscosity. Two adhesives with identical viscosity can need different equipment based on cure chemistry alone.