Answer Posted / bala10286
in case of positive displacement pumps (ex:reciprocating
pump) the piston or mechanical member directly creates the
vacuum or lower pressure such that the water or liquid is
sucked in..
in case of centrifugal pumps...the impeller just
displaces the water due to the centrifugal force..as the
water at center of impeller is displaced to the
casing..partial vacuum gets created at the eye of impeller
and hence suction of new water takes place..
if there is no water around impeller..only air is
present and it cant be displaced by the pump impeller as air
is compressible..the pump impeller is designed to handle
water or liquid.. therefore to remove the air and fill the
casing with water the priming is carried out..
there is no need of priming if there is an foot
valve and its working well...
| Is This Answer Correct ? | 17 Yes | 2 No |
Post New Answer View All Answers
What does Nominal size in a valve means like NG6,NG10 etc
I am doing 3rd year mechanical engineering. I want to place in good mechanical engineering core company. So please guide me how to prepare for interviews, and what can i do for placed in good company?
plz send me the aptitude test paper for hpcl.
Which is first stress or strain?
How do concrete pumps work?
What is brain of the computer?
What is an oil mist detector
respected sir, kindly send me some interview questions , which are asked in trainee marine engg..
What are safety considerations in welding job?
What are the causes of failure of superheater tubes ?
Why coupling should be located very near to the bearing? Why lap joint not recommended for tensile force?
sir, please send previous years RRB junior engineer (mechanical) exam papers
Explain nuclear reactor?
working of nuclear power plant
What is IS standard in case of mode of measurement for ducting