Description

 The fluid end expendables mainly include valve&valve seat, plunger, spacer, oil ring, spring seat, discharge cover, retainer nut, spring, inserts and seals etc, of which valve&valve seat and plungers and packing box are the most frequently required expandables.
 As an important sealing part, the packing box is also among the most expandable spare parts of fluid end.
The packing box is used to seal and secure the high pressure in fluid chamber while the plunger is making reciprocating motion.