One of your guys found a leak. Whether it was a whiff in the air or a puddle on the ground, this is not good news—especially in the highly-regulated Northern California Bay Area. If you’re lucky, the leakage is small, though noticeable, and you can remedy it before it brings a critical pumping process to a halt. In the worst case, it’s catastrophic, with ramifications of sanctions from Cal/OSHA or the BAAQMD. What can you do to prevent these situations? After all, aren’t seal support systems supposed to enhance pump reliability?
I’ve worked to prevent mechanical seal support failure causes with process and reliability engineers for many years and it usually comes down to one of two major factors: changes in process conditions and the inability to maintain the required seal chamber temperature. Let’s look at each of these, acknowledging that there’s often interplay among the variety of seal support systems, mechanical seals, and pumping processes involved.
It’s not unusual for pumping process conditions to change during the course of a pump’s life. Pumps installed years ago were likely designed for a specific purpose. In the ensuing years, with changes to accommodate a demand for product variations or attempts to boost process productivity or efficiency, mechanical seals and seal support systems may no longer be able to adequately support the pump. I’ve listed key factors to consider in the table below.
| Factor | Remedy |
| Change to process fluid running at higher temperatures |
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| Increased particulates in process fluid abrade seal faces |
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| Increased or decreased pumping pressure |
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As you might expect, pumps, mechanical seals, and seal support systems need to be carefully matched to avoid mechanical seal support failure. Changes in process conditions can quickly upset the balance required to ensure pump reliability.
Excessive seal chamber temperatures are virtually guaranteed to result in mechanical seal failures that lead to leakage. I’ve addressed temperature factors associated with changes to process conditions above. Now let’s focus on problems tied to a mechanical seal support system’s failure to maintain the proper seal chamber temperature. In these scenarios, there have been no changes to the process fluid. The problem lies within the seal support system. Here are the most common problems to consider:
| Factor | Remedy |
| Current cooling capacity of the process fluid is inadequate |
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| Inadequate barrier or buffer fluid flow rate |
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| Coking, icing, or oxidation on the atmospheric side of seal faces |
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For any of these systems, pinched, crimped, or leaking tubing that conveys cooling fluid can also be the culprit. Temperature and flow are closely related. It can be difficult to determine if a mechanical seal support failure cause is one or both of these factors. Begin by identifying or ruling out the simplest problems to fix. In the simplest case, it’s merely a control adjustment to an external source to restore the proper flow of cooling fluid. In more complicated cases, a design improvement may be the only way to eliminate a continually recurring problem.
Although a few of these mechanical seal support failure causes can be quickly diagnosed and resolved, solving the more complex problems requires the expertise and experience of a seal support system vendor with deep industry knowledge.
A local partner like Swagelok will help you diagnose your mechanical seal support failure causes, on-site. Whether the recommendation is as simple as a heat exchanger upgrade or a redesign and replacement of an outdated seal support system, you’ll benefit from the expertise of a team of field engineers and technicians certified in ISO 9001. There’s no better partner in Northern California to provide you with a full range of services, including consulting, design, fabrication, testing, training, and on-going technical support.
To find out more about how Swagelok Northern California can help you diagnose and solve the most common mechanical seal support failure causes by providing expert consultation and Assembly Services, contact our team today by calling 510-933-6200.
Paul holds a B.S. in Mechanical Engineering from North Dakota State University. Before joining Swagelok Northern California, he was the West Coast Regional Sales Manager for an organization focused within the pneumatic and hydraulic industry where he supervised product distribution throughout the western United States, Canada, and Mexico. While in this role, he was able to help provide technical and application-specific expertise to customers and distribution to drive specifications.