In the oil and gas industry, mechanical seal failure is the number one reason for pump downtime. For a reliability technician, seeing a leaking seal just weeks after installation is frustrating.
But seals rarely fail on their own. Usually, it is a symptom of a bad operating condition or installation error. In this guide, we will look at the real reasons why seals fail and how you can prevent them.
1. Dry Running (The Silent Killer)
Dry running happens when the pump operates without liquid between the seal faces. This causes immediate heat generation and thermal cracking.
Common Causes:
- Starting the pump without proper venting (priming).
- Closed suction valve.
- Vapor lock in the seal chamber.
Technician’s Tip: [Yahan aap likhein ke pump start karne se pehle aap venting kaise check karte hain aur operator ko kya advise karte hain?]
2. Misalignment (Shaft & Coupling)
Even the most expensive API 682 seal cannot survive if the shaft is vibrating. Misalignment puts excessive load on the seal faces and bearings.
Field Experience: [Yahan likhein ke laser alignment karte waqt aap kitni tolerance rakhte hain? 0.05mm ya us se kam?]
3. Improper Flush Plan (API Plans)
The flush plan is the life support system of a mechanical seal. Whether it is Plan 11, Plan 23, or Plan 53A, if the clean fluid isn't reaching the faces, the seal will fail.
What to Check: Check Pumping rings are properly engraved on retainer,flushing cooler,Strainer. All must be properly De-Chocked.
4. Vibration Issues
High vibration can open the seal faces, allowing particles to enter and damage the lapped surfaces.
Pro Tip: Always check the pump's "Soft Foot" before final alignment. A soft foot can twist the casing and distort the seal chamber.
Conclusion
Replacing a seal is easy, but finding the root cause requires skill. Next time you see a leak, don't just change the seal—investigate the system.