The oil seals on a multistage centrifugal compressor in a natural gas pipeline were not meeting performance requirements and the user felt there should be options to improve overall compressor performance. The OEM service team did not respond effectively to customer needs. Consequently, they needed a better solution.
Client Challenge:-
The user was looking to improve compressor performance, and also reduce gas emissions while allowing for pressurised hold. Therefore, replacing the existing oil seals with dry gas seals was a clear option to achieve these objectives,
Furthermore, the entire upgrade needed to be completed without necessitating any modifications to either the compressor shaft or casing.
Our Response:
- Evaluate the condition and performance of the existing seals
- Review compressor operation and also the operating environment
- Provide an inspection report c/w photographic evidence and insight into performance issues
Recommendations/Work Scope:
- Design tandem K-DGS dry gas seal with integral K-CBS barrier seal such that compressor casing modifications would not be necessary
- Modify the existing bearing brackets to provide space for the K-CBS and associated porting
- Establish a method for adapting the shaft for dry gas seals
- Perform rotor dynamic analysis to determine suitable bearings for winter and summer rotor configurations
- Design a seal panel with flow and pressure transmitters to connect with the control room for remote operation
Benefits:
- Gas emissions reduced to levels better than those estimated
- Complex, high maintenance seal oil system eliminated
- Pressurised hold now possible
- K-DGS seal performance persuaded the client to commission retrofits of a further 9 identical units
- Responsive, high-quality seal support for current and future requirements
For more details on this case study, or to discuss how we can help with repair, maintenance and support for your high-dependency mechanical seals, contact us.