

Graco 164891 Packing O-Ring — PTFE seal for selected Graco heater modules (e.g., Viscon HF). Use this when servicing high-pressure fluid paths; verify in your parts manual before ordering.
The Graco 164891 Packing O-Ring is a PTFE (Teflon) sealing ring used in high-pressure fluid paths on certain Graco heaters and related modules to maintain leak-free operation and long service life.
| Part Number | 164891 (may appear as 164-891) |
|---|---|
| Type | Packing O-Ring (seal) |
| Material | PTFE (Teflon) for chemical resistance and low friction |
| Typical Use | Heater core kits and high-pressure fluid heater assemblies (e.g., Viscon HF) |
| Fitment Tip | Always confirm against your specific machine’s parts manual before ordering |
| Question | Answer |
|---|---|
| Does this O-ring fit airless sprayers like Ultra Max II or Mark series? | It is primarily used in heater systems (e.g., Viscon HF) and related modules. Check your sprayer’s parts list to confirm 164891 is specified. |
| What’s the advantage of PTFE for this seal? | PTFE offers excellent chemical resistance, low friction, and durability under high pressure and temperature variations. |
| How do I confirm compatibility? | Open your machine’s parts manual or schematic and verify the exact part number for the sealing location you’re servicing. |
| Any installation tips? | Inspect sealing surfaces, use appropriate lubricant if specified, and avoid twisting or overstretching the ring during installation. |