

Graco 164864 Plate, Diaphragm—zinc-alloy support plate used inside diaphragm-type regulators and back-pressure valve assemblies. Verify fit by matching the part number in your machine’s service manual.
This plate is used inside specific Graco diaphragm-type regulators and back-pressure valve assemblies. Add a machine to this list only if its service manual lists part 164864 in the regulator/valve assembly.
| Part Number | 164864 |
|---|---|
| Part Name | Plate, Diaphragm |
| Material | Zinc alloy |
| Typical Location | Inside diaphragm-type regulator or back-pressure valve assembly |
| Approx. Size (ref.) | Inner Ø ≈ 0.4″, Outer Ø ≈ 2.4″ (verify against your assembly) |
| Function | Provides rigid support to the elastomer diaphragm; maintains sealing and response characteristics |