– why guessing is dangerous.
Many people base their selection of mechanical seals on the suction pressure.
It sounds logical—but in practice, it often leads to problems.
The actual sealing pressure frequently deviates significantly.
In single-stage centrifugal pumps, it is often around two-thirds of the final pressure.
The result:
• Wear
• Failures
• Unnecessary downtime
Benjamin Wessling, our ttv expert for mechanical seals, sums it up:
“What matters is the actual sealing pressure—not the assumed one.”
Our recommendation: Don’t rely on rule-of-thumb values.
Talk to the manufacturer or measure the actual pressure—e.g., with a pressure gauge.
Because:
The correct pressure rating determines service life, operational reliability, and costs.
Would you like to review your design or do you have questions about mechanical seals?
Write to us or contact us directly—we’re happy to assist you.