Many of the developed world's refinery and petrochemical processing plants were built over 30 years ago. The industry, through good maintenance practices, achieves high levels of reliability from pumps and sealing devices. The high cost of replacing pumps and the dependability of existing machines has restricted the wholesale replacement of these mature assets. Consequently, there are extremely large populations of pumps and seals operating today whose designs date back to the 1960's.
The mechanical seals fitted on these old generation machines will, in many instances, no longer meet current regulatory requirements in terms of emissions or best practice in terms of safety. Upgrading these machines to modern sealing devices is becoming an increasing requirement. Many engineers wish to incorporate the API 682 mechanical seal standard in the upgrade process. On paper this sounds relatively straightforward, however in practice, this is fraught with difficulties. The physical size requirement for modern mechanical seals does not lend itself to the installation on old machines. Pump modification or replacement to accommodate modern seals can be at considerable cost and/or interruption to production. The paper will explore some of the areas of difficulty and provide some ideas for potential economic and elegant solutions.