McMaster 7739K176 High Pressure Galvanized Steel Pipe Fitting Union Straight Connector, 1 NPT Female G6599673 Pressure 4000 psi Coupler Body Pressure 4000 psi Coupler Body Material Steel Coupler Finish Zinc Plated Series 6600 For Use With ISO 7241 1 Series A Coupler Body Material Steel Coupling Locking Type Sleeve Parker Interchange 6602 6 6 Bearing Material Stainless Steel Locking Mechanism Ball Operating Temp Use with Rotary or Automatic Floor Machines Standards Green Seal Certified Pad Aggresiveness 3 Union connectors separate into three pieces so you can access your line without unthreading pipe connections they have excellent strength to handle high pressure applications