A Safematic SAB/140 pressurised double mechanical seal in a vertical pulper on the main production line at a paper mill in Scotland was failing after more than 5 years in service. The decision was quickly taken to replace it with the spare seal. However, it had been in their stores for over 5 years.
When the mechanical seal on a vertical pulper began to fail, the mill needed to act to ensure a complete seal failure didn’t lead to the forced shut down of their core process plant. The spare seal had been in the stores for over 5 years and there were concerns that it was not fit for purpose.
NASH was approached with the request for a comprehensive inspection and pressure test to ensure the spare seal did not pose a risk of premature failure. Given the condition of the installed seal, the spare seal needed to be installed as quickly as possible and the mill could not afford 4-6 weeks for it to be inspected and tested by the seal OEM.
Once the spare seal was installed, the company also wanted to explore the most cost-effective option for repairing the spare seal and returning it to their stores.
- Strip and inspect the spare seal within 24 hours of receipt.
- Determine the condition of all seal components.
- Repair/replace parts as necessary, assemble & pressure test.
- Quickly return the spare seal for immediate installation.
- Receive the failed seal after removal.
- Complete strip down and failure/condition analysis.
- Provide comprehensive inspection report.
- Repair/replace parts as required.
- Assemble, pressure test and pack for long term storage.
Developing the best aftermarket solution for this type of seal demonstrates key elements of the NASH approach. In the first instance, time was of the essence. There was a risk that the installed seal would fail completely necessitating the shutdown of a core production line. Once the installed seal was replaced, it needed to be inspected and assessed to determine if it could be refurbished effectively. The refurbishment option was likely to offer a more cost-effective solution than replacement with a new seal.
However, in both cases, the speed of turnaround and cost-effectiveness had to be balanced with engineering performance. It is vital the complex mechanical seals fitted to high dependency equipment must perform to specification. The NASH approach combines an uncompromised blend of seal experience, engineering expertise and independence, putting us in a unique position to deliver the most appropriate solution every time.
- Re-lap all seal faces.
- Replace all secondary seals.
- Static pressure test.
- Repair inboard & outboard seal assemblies.
- Replace all secondary seals and fasteners.
- Assemble & static pressure test.
- Pack for long term storage.
Both mechanical seals returned to ‘as new’ performance specification.
Here is the failed seal, as received by NASH and fully repaired, ready for dispatch….
- Spare seal returned for immediate installation within 1 week.
- Rapid response addressed concerns over the increasing risk of installed seal failure.
- Failed seal fully assessed and repaired including a comprehensive inspection report.
- Cost of refurbishment significantly lower than replacement.
- End-user confidence in seals fully assessed and restored by proven engineered mechanical specialists.
- Flexible, responsive and proven engineered mechanical seal support for all future requirements.
Overall, this is a great example of how NASH delivers world-class aftermarket support for the engineered mechanical seals used in your high-dependency pumps, mixers and turbomachinery.