Which pump installation would require an...

Which pump installation would require an external source of sealing water?

🔍 Key Concepts

• Mechanical seals vs. stuffing boxes on pumps and why they need sealing water • Which systems normally already have clean, pressurized water available in their own line, and which may handle air/dirty mixtures • How pump suction conditions (vacuum, entrained air, dirty water) affect the need for an external sealing water source

💭 Think About

• Think about which pump is MOST likely to operate with suction conditions that are poor (lots of air, high vacuum, dirty liquid) so that its own pumped liquid is not reliable or clean enough to cool/lubricate the seal. • Ask yourself: on which system would you LEAST want to depend on the system’s own liquid to protect the shaft seal, because that system might be empty or full of debris when you need it most? • Consider which of these pumps is most commonly fitted with a mechanical seal that specifically calls for a separate, reliable source of clean water for sealing.

✅ Before You Answer

• Verify which pump is most likely to see intermittent service, sometimes pumping air or very little liquid. • Check which system is most prone to abrasive contaminants (mud, sand, sludge) that would damage a seal if used as sealing water. • Confirm which pump’s normal operating liquid supply is NOT guaranteed to be present and clean at the moment you start the pump.

🔍 Key Concepts

💭 Think About

✅ Before You Answer