4 replies to this topic

[alejandraarias]

Hi Everyone

 

I have been calculating a PSV for a blocked outlet relief scenario (discharge of a oil pump.) and sizing the discharge line, the results show that i should use a 8" diameter line, but I can't use that diameter because of the intallations and i tried with 6" and the mach number result is 0.77. I was wondering what are the effects of having high mach number in a liquid relieving that will connect to the suction of the pump?, the length is not more than 4 meters.

 

PM: 98.42

Density: 41.48 lb/ft3

Set pressure: 1280 psig

Relief temperature: 130 ºF

Rated Flow: 73674.9 lb/hr

[fallah]

 

I have been calculating a PSV for a blocked outlet relief scenario (discharge of a oil pump.) and sizing the discharge line, the results show that i should use a 8" diameter line, but I can't use that diameter because of the intallations and i tried with 6" and the mach number result is 0.77. I was wondering what are the effects of having high mach number in a liquid relieving that will connect to the suction of the pump?, the length is not more than 4 meters.

 

 

Hi,

 

Does the fluid still remain liquid inside the tail pipe at such high mach number?
 

[alejandraarias]

The phase fraction is

vapor= 0.0387

liquid= 0.9613

I mean at that mach number and velocity.

[serra]

for generic piping I evaluate both mach number and induced stress, see

 

http://www.cheresour...with-hem-model/

 

however  (73674.9 lb/hr / 41.48 lb/ft3 * 0.0283...) I get about 50 M3/h ...

[fallah]

 

The phase fraction is

vapor= 0.0387

liquid= 0.9613

I mean at that mach number and velocity.

 

 

Hi,

 

In general, the situation of the pump wouldn't so good to receive such vapor fraction via the suction line...
 

Please submit a simple sketch of the system you described along with the relevant info to help for submitting more accurate and logical response...