Calculate API Plan 11 Flow rate w/throat bushing
Calculate API Plan 11 Flow rate w/throat bushing
(OP)
I Have recently joined a seal company and have the following question.
If I am given an orifice size on the plan 11 line and throat bushing diametric clearance of 0.008"..what formulae do I use to calculate how much flow rate is being generated..and if I open up the throat bushing clearance to approx 0.020"..would that increase my flow rate as my orifice is still the same on the plan 11 line..would not my orifice dictate the flow rate or is it a combination of both? Thanks
If I am given an orifice size on the plan 11 line and throat bushing diametric clearance of 0.008"..what formulae do I use to calculate how much flow rate is being generated..and if I open up the throat bushing clearance to approx 0.020"..would that increase my flow rate as my orifice is still the same on the plan 11 line..would not my orifice dictate the flow rate or is it a combination of both? Thanks





RE: Calculate API Plan 11 Flow rate w/throat bushing
Johnny Pellin
RE: Calculate API Plan 11 Flow rate w/throat bushing
RE: Calculate API Plan 11 Flow rate w/throat bushing
Discharge pressure: 100psig
Suction pressure: 10psig
vapour pressure: 15psia
pressure between throat bush & impeller: 15psig
orifice on plan 11 line: 0.125"
I would first determine the required seal chamber pressure: VP+50psi = approx. 50psig
For argument sake, with a press diff of 50psi and orifice size of 0.125", the flow rate is 3GPM. I would then insert the seal chamber pressure, 50psig, and flow rate, 3GPM, in the throat bushing leakage formula and calculate h, gap, required..
But if I change the gap to a larger number, then the flow rate will change and the pressure drop across the throat bush, 35psig, will change..how would I calculate both as they are related?
RE: Calculate API Plan 11 Flow rate w/throat bushing
RE: Calculate API Plan 11 Flow rate w/throat bushing
RE: Calculate API Plan 11 Flow rate w/throat bushing
I will quickly explain my situation, I recently got hired in a seal company and would like to progress in the company. I have asked 2 out of the 3 engineers who have an idea but are not sure how the calcs work. I refuse to accept the software as is and would like some more insight. If there are any sites you could refer me to or help me out on this forum, please do so.
Thanks.
RE: Calculate API Plan 11 Flow rate w/throat bushing
Johnny Pellin
RE: Calculate API Plan 11 Flow rate w/throat bushing
But nowhere in the formula does it take into consideration the pipe diameter. I remember there being a beta ratio = orifice dia/pipe dia..this shows the flow rate is not a function of the pipe dia which I remember it was.
Am I using the right formula here?