Graco piston 390-495

A piston in a Graco airless paint sprayer or pump is a precision-made mechanical component inside the pump assembly that moves back and forth to:

• Draw fluid (paint/coating) into the pump chamber on the upstroke, and
• Force that fluid out under high pressure on the downstroke, which then travels to the hose and spray gun.
  This piston action creates the pressure that makes airless spraying possible.  

Graco pistons are engineered to work with tight seals and durable materials so they hold pressure well and resist wear — critical for consistent spray performance and long life.