Viscous fluid metering device with quick change nozzle

A method for retaining a nozzle in a fouling resistant nozzle holder, comprising the steps of:

• coaxially inserting a nozzle having a cylindrical portion into a cylindrical cavity;
• rotationally positioning the nozzle relative to the nozzle holder to rotationally align a nondiametrical chordwise passage through the nozzle holder with a complementary chordwise passage of the nozzle;
• and
• inserting a retaining member through the aligned holder passage and nozzle passage such that the retaining member secures the nozzle in the holder.

A fouling resistant changeable nozzle assembly comprising:

• a metering device;
• means for holding a cylindrical nozzle;
• a nozzle having a cylindrical portion proportioned for close fitting coaxial insertion into the holding means;
• the holding means further comprising means for retaining the nozzle being pierced by a passage oriented substantially perpendicular to the bore axis and passing through the cylindrical bore on a non-diametrical chord;
• the nozzle having a complementary passage alignable with the nozzle holder passage;
• and
• a retaining member proportioned to pass through the nozzle holder passage and the nozzle passage whereby the nozzle is retained in the cylindrical bore.