Additive pump
A seal assembly, for an additive pump having a reciprocating piston, is provided. The seal assembly includes a seal carrier having first and second components each having a bore therein to receive the piston. Each component has an end face arranged to abut one another when arranged axially on the piston, and a face seal is interposed between the end faces to inhibit egress of fluid between the end faces. A pair of circumferential seals at axially spaced locations are provided along the seal carrier and operable to engage the piston during reciprocating thereof, and a drain port intersecting one of the bores intermediate the seals is provided to permit egress of fluid from between the seals.
1. A seal assembly for an additive pump having a reciprocating piston, said seal assembly including a seal carrier having first and second components each having a bore that receives said piston, each component having an end face arranged to abut one another when arranged axially on said piston, a face seal interposed between said end faces to provide a static seal between said first and second components and to inhibit egress of fluid between said end faces, a pair of circumferential seals at axially spaced locations along said seal carrier that engage said piston, and a drain port intersecting one of said bores intermediate said circumferential seals to permit egress of fluid from between said circumferential seals.
2. A seal assembly according to claim 1 wherein said face seal is located in an undercut of one of said components.
3. A seal assembly according to claim 1 wherein one of said circumferential seals is located in a recess formed between said end faces.
4. A seal assembly according to claim 3 wherein another of said circumferential seals is located in an oppositely directed end face on one of said components.
5. A seal assembly according to claim 4 wherein said other circumferential seal is located in a recess formed on said oppositely directed end face.
6. A seal assembly according to claim 1 wherein an additional circumferential seal is located on one of said components.
7. A seal assembly according to claim 6 wherein one of said circumferential seals is located in a recess formed between said end faces of said components and the other of said circumferential seals are located in a counter bore formed in an oppositely directed end face of one of said components.
8. A seal assembly according to claim 1 wherein a second face seal is located on an oppositely directed end face of one of said components.