What happened when Delivery valve closed and Suction valve open in centrifugal pump.(in running conditions)
Answer Posted / phani
After some period, churning effect will takes place, which means dry run. This is due to continuous water circulation within the casing. After some period, due to friction between pump casing and flowing water, heat will be generated, slowly water getting heated up and further evaporation takes place, then pump will be under dry run condition.
Internal circulation means, discharged water can't escape from casing, so only the way to escape is passes through wear ring clearance and came to suction, again from suction to discharge water will flow.
Due to this dry run, shaft and casing will be over heated and thermal expansion takes place, shaft may brake at time.
If bluish or burning marks are found on shaft/impeller, it means that "pump runs on shut off head or Churning effect", it is confirm.
| Is This Answer Correct ? | 6 Yes | 0 No |
Post New Answer View All Answers
what is air intake system
When looking at a flanged extension pipe and it is labeled DN20, just what does that mean or intel?
What type welding electrode is used to weld chrome?
In some engines glycerine is used in place of water for cooling of engine. Why ?
if we not carried out B check at mean time in DG set what will be happen?
Is it the relation between friction and power losses ? is it relation among stress, friction and power loses in cicular ring ?
How is the gear ratio calculated?
what is Direct control valve ? explain its practical applications?
i have been selected for the HAL interview? what type of questions can i expect? technical or personal? pls help me in this regard and mail to sankar_aji@yahoo.co.in
What is the purpose of turning gear
what is the difference between fire grate in a boiler and the burner? and is the fire grate is the furnace of the boiler?
how water evaporated in sea
At 50 Centigrade (Fuel oil) what is its cast?
hi sir would u plz kindly send me d previous years IOCL test papers......plz send it to this email id...jomygeorge787@hotmail.com
What kind of pipes are used for steam lines?