How to Extend the Service Life of Metal Bevel Self-Tightening Hard Seals

The service life can be increased by 30% to 50% by optimizing three aspects: installation, production maintenance, and routine inspection. The following are specific techniques:

1. Establishing a Sturdy Base During Installation: Clear the sensor mounting holes of any burrs or remaining contaminants prior to installation. To stop contaminants from harming the sealing surface and creating initial damage, the bevel and mounting contact surfaces need to be completely cleaned.

strictly regulate the installation torque in accordance with the specifications provided by the manufacturer. Avoid overtightening: Excessive torque might harm the bevel, while insufficient torque will result in insufficient pre-tightening force and easy leaking. In general, a torque of 8–10 N·m is enough for M8 standards.

Apply a uniform layer of high-temperature graphite grease on the bevel during installation. This enhances the sealing effect, minimizes installation damage, closes small gaps, and makes subsequent disassembly and replacement easier.

2. Minimize Production-Related Damage

Prevent Instantaneous Overpressure During Cold Start: To lessen the immediate effect of high pressure on the seal, gradually raise the injection pressure during preheating rather than applying the full pressure right away.

Control Melt Temperature Stability: Avoid operating at extremely high temperatures for extended periods of time as this causes metal oxidation, decreases seal hardness, and promotes aging.

Minimize Frequent Start-ups and Shutdowns: Frequent starts and shutdowns accelerate fatigue deformation of the sealing surface by subjecting the seal to alternate pressure. For longer service life, continuous production is more advantageous.

3. Consistent Upkeep to Postpone Aging

Every six months of production, disassemble and clean. To avoid crystals embedding into the sealing surface and creating irreversible damage, clear the melt crystals on the sealing bevel, look for any small indentations, reapply graphite grease, and then reinstall.

Retighten Torque Every 12 Months: The pre-tightening force will somewhat decrease during extended high-temperature production; retightening can avoid small leaks and restore the sealing pre-tightening force.

Proactive Replacement: To prevent unexpected leaks and shutdowns, it is advised to replace the seal under ultrahigh pressure (>250MPa) circumstances, even if there is no leakage after 18 months of usage.

The seal life can be increased from 18 months to 24–30 months under typical operating circumstances of 200–250 MPa by maintaining the seal using the following techniques. This greatly lowers the frequency of replacement and the risk of unexpected shutdowns.