Seal selection is a system decision. Media, pressure, speed, temperature, motion pattern, allowable leakage, counterface condition, contamination and maintenance access must be considered together. A material name by itself is not enough to approve a rotary union.
Model-specific limits: Select within the pressure, speed, temperature and media limits on the current product page and approved drawing for the chosen configuration.
Three seal families, three different design roles
| Seal family | General construction | Typical strengths | Items that require confirmation |
|---|---|---|---|
| Elastomer O-ring | Elastomer ring installed in a machined groove | Compact construction and simple replacement | Compound, groove geometry, clearance, lubrication, pressure, motion and temperature |
| PTFE composite or lip seal | PTFE-based dynamic sealing element, sometimes combined with an elastomer backup seal | Low friction and broad media options when the exact compound is compatible | Filler, counterface finish, runout, pressure, speed, temperature, creep and wear |
| Spring-energized PTFE seal | PTFE-based sealing element preloaded by an energizer | Can help maintain contact force in demanding, application-specific designs | Spring design, installation space, counterface, leakage limit and validation of the complete assembly |
None of these families is universally better. The correct choice depends on the complete operating envelope and on the approved construction of the selected model.
Where PTFE-coated O-rings fit
An O-ring coating is different from the PTFE dynamic sealing element in the comparison above. In a composite slipper-seal assembly, the O-ring provides preload and elastic support. See our PTFE-coated O-ring guide for the optional coating configuration, process photographs, and supplier thickness report. Selection depends on the working medium and operating conditions; it is not a standard feature of every model.
If the immediate problem is leakage, start with the five-step rotary union troubleshooting guide before choosing replacement seals.
Current published Begapunk model examples
The table below summarizes values from the current public model pages. For order-specific selection, use the approved drawing or model-specific datasheet.
| Model | Maximum pressure | Maximum speed | Selection boundary |
|---|---|---|---|
| BP-2P-0001 | 1 MPa | 200 RPM | Two independent passages; confirm medium, temperature and duty |
| BP-2P-130-0001 | 5 MPa | 80 RPM | High-pressure, low-speed model; use only within its published limits |
| BP-2P-95-0005 | 1 MPa | 200 RPM | G1/8 clamp and release ports; use the published limits |
| BP-2P-50-0001 | 1 MPa | 100 RPM | Protective shroud and labyrinth for dusty environments |
These values describe the public standard configurations. For custom configurations, material, dimensions, seal arrangement and operating limits are confirmed in writing.
Information needed before seal selection
- Media: composition, concentration, contamination and required cleanliness.
- Pressure: normal pressure, peaks, vacuum conditions and whether passages operate independently.
- Motion: continuous rotation, indexing or oscillation; maximum and typical speed; duty cycle.
- Temperature: media, ambient and expected temperature rise at the sealing interface.
- Leakage criterion: an agreed limit, test medium, pressure, duration and measurement method.
- Mechanical interface: counterface material and finish, runout, alignment, mounting loads and available space.
- Maintenance: inspection access, acceptable downtime and replacement procedure.
How production leak testing fits
Begapunk's current standard production check is performed after final assembly. Each passage is checked separately with compressed air at 1.0 MPa while the other passages remain vented. The test uses approximately 1 second of pressurization and 4 seconds of hold time; a detector alarm identifies a nonconforming unit for segregation and investigation.
This production inspection verifies each finished unit under the documented conditions. Model operating limits, service-life expectations and application-specific leakage requirements are evaluated separately. See the documented process under 100% Leak Testing.
Selection note
Seal performance and maintenance intervals depend on the selected model, seal geometry and actual operating conditions. Any leakage requirement should be expressed as a measurable limit with an agreed test method. Confirm the final operating limits for the selected configuration before ordering.
Send Your Seal Requirements
Send the medium, pressure, motion, temperature, passage count, mounting drawing, and leakage criterion. We will reply with a suitable standard model or the custom configuration details still needed.