Piston Rod Pressure Packing Assemblies
RONDER supplies piston rod pressure packing assemblies for reciprocating compressors. Packing ring sets sit inside a packing case and seal around the reciprocating piston rod to control gas leakage along the rod. Material formulations, ring arrangements and auxiliary connections are selected for the gas, operating conditions and compressor configuration.
Functions in the Compressor
| Component | Location and function |
|---|---|
| Piston rod pressure packing | Between the cylinder and the distance piece; restricts gas leakage from the cylinder along the piston rod. |
| Intermediate partition packing | Used in applicable divided distance-piece arrangements to provide a seal between compartments. |
| Oil-wiper packing (oil wiper rings) | On the frame side; remove lubricating oil from the rod to limit crankcase oil entering the distance piece or cylinder. |
| Piston rings and rider bands | On the piston inside the cylinder; provide cylinder sealing and piston support respectively. Their location and function differ from piston rod packing. |
Each component has a separate role. Selection starts with gas sealing, oil control and piston support requirements, then the compressor interfaces and arrangement.
Packing Case and Ring Arrangement
Packing cups house the ring sets, while the flange and fasteners secure the packing case in position. The rings, rod and packing-cup sealing faces together form the sealing path. Ring design, arrangement and material formulation affect sealing and wear.
Cooling arrangements follow the frictional heat and available cooling supply. For a buffer gas system, provide the gas supply, vent path and distance-piece arrangement. For purging, state the connection purpose and gas-supply requirements.
Material Formulations and Operating Ranges
RONDER packing is available in 8 nonmetallic material formulations, selected for the gas and operating conditions.
| Item | Product information |
|---|---|
| Nonmetallic material formulations | 8 |
| Operating temperature | <300°C |
| Operating pressure | <400 bar |
| Continuous operation without failure | ≥8,000 h |
The temperature and pressure ranges can apply simultaneously. The material and ring arrangement are selected for the compressor duty; continuous operating time depends on the gas, lubrication, rod condition, installation and operating conditions.
Information Needed for Selection
Provide the compressor manufacturer and model, cylinder or stage, piston rod diameter, stroke and speed, together with:
- Gas composition, including particulates, condensate and other contaminants;
- Pressure and temperature at the packing, including normal and variable-load operating ranges;
- Lubricated or nonlubricated operation, lubrication method and oil supply;
- Existing packing case, mounting interfaces and piston rod surface condition;
- Cooling, auxiliary-gas and vent conditions, plus available leakage, wear or maintenance records.
When replacing packing rings, inspect the rod and packing-cup sealing faces, cooling passages and static seals as well. Other parts of the assembly can affect sealing even after new rings are fitted.
Discuss a Packing Requirement
For packing selection or replacement, send equipment and operating information, drawings and operating records to sales@ronder-valve.com.
Related products: Reciprocating Compressor Valve Catalogue.
Related technical case: Piston ring redesign for uneven wear and short service intervals.
Packing localization case
Coal Liquefaction Compressor Parts and Valve Refurbishment | RONDER