If the packing gland of a centrifugal water pump is leaking too much, you should
a) tighten up the gland until all leakage has been stopped
b) tighten up the gland but permit a slight amount of leakage
c) tighten up the gland as far as is possible
d) throttle the suction valve a little
e) tighten up the gland until there is 10% leakage
Answer: B
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Power Engineering Chapter 74
- You discover that your feed water pump is not delivering sufficient water. A possible cause is
- If a pump is running and has no discharge pressure, what will you do?
- If pump speed is too high
- A plugged impeller symptom or result will be
- Shaft misalignment during operation of a pump can be caused by bearing wear, thermal expansion, and
- The component of a mechanical seal which prevents axial leakage is
- Any leakage occurring through the surfaces of a mechanical seal will
- Lantern rings: 1. prevent liquid leakage from the pump 2. are fed by a liquid 3. provide a seal to prevent air from entering the pump 4. are mostly used on high lift pumps
- Compression type packing: 1. prevents air from entering the pump 2. reduces the maintenance cost on pumps 3. protects the shaft from scoring and corrosion 4. is used with all mechanical seals
- Mechanical seals: 1. are used where leakage is objectionable 2. replace stuffing boxes 3. provide a better seal than packing 4. are less costly than stuffing boxes
- A stuffing box: 1. stops air leaking into the casing when the pressure is below atmospheric 2. decreases leakage out of the casing when the pressure is above atmospheric 3. is always supplied with a lantern ring 4. is filled with packing
- Wearing rings: 1. are used on impellers 2. are used on the casing 3. give protection to the shaft 4. reduce the maintenance cost of the pump
- Wear rings are usually constructed of
- Pump wear rings are installed on an impeller by set screws, threading or
- Mechanical seals:
- Most pump troubles occur:
- A slight leakage is desired between the pump shaft and the packing in order to:
- The area around a pump shaft, where packing material is placed to reduce leakage past the shaft, is known as a:
- While a pump is operating, your inspection should include the following:
- Another name for a lantern ring, used in a pump is:
- Compression type packing:
- Before starting a pump, check
- The seal cage on the shaft of a centrifugal pump:
- The main advantage of a pump using a mechanical seal is: