TD2K, let me ask you this. I did record right at the pump inlet. The recorded vacum was 13.5 In Hg. Can it be possible with the calculation that instead of adding the 9.7 ft. of hose to the final number at the end of the calculation that the psi per ft loss is all I need to plug in. What I...
Thanks TD2K. I just ran some rough numbers with your answer to my question. If I add the 14.7 to the 6.7 psi I do get a more accurate calculation. This is maybe what I need to do. I may be seeing absolute in negative units (In.Hg i guess?). The 6.7 + 14.7 x 0.06804=1.46 psia ? loss per ft...
Also in addition to your response TD2K, the psig that you see is the loss per ft of hose length. At the point recorded it showed 13.5 In Hg. so the loss I am trying to calculate is related to psig per ft. loss in pressure. I am trying to convert that to a In. Hg. calculation. Thanks for your...
In response to TD2K
The 0.06804 converts the PSIG(which I belive is correct in the calculation I posted, please correct me if i am wrong) to PSIA. What are your thoughts on this.
TD2K
I have posted the response as a new subit question and is titled Hydraulic Fluids at minus temperatures TD2K response.
I did this hoping that you would see it. I included the calculations that I am using. I hope you can respond to that calculation a advise me if I need to factor somthing...
In response to betelja.(mechanical)
It very well could be since the viscosity of the oil is high the slower the movement of cylinders etc..
As far as pump damage is concerned short term is ok for the axial piston unit I am using and I agree during initial start-up of the unit cavitation is...
In response to ChasBean1(Mechanical).
You are correct in being off by a Factor of 10. See example below. The calculation is as stated above and I have converted into absolute pressure and than to in. Hg.
The below are
For the Reynolds (Nr) number
3162 constant x 4 gpm / 7000 Cst x 1 d = Nr...
butelja(mechanical)
Thanks for your reply.
You are correct and it is a pump suction line. We can operate short term to 14 in. Hg. and that is how we are appling pump in this aplication. The in. Hg never stays there due to the system heating up. What problem I run into is trying to calculate...
In response to TD2K (chemical). The calculation that I am using is as follows.
First is finding the Reynolds number. Nr = 3162xQ / ud
Nr= Reynolds number
u = Viscosity in Cst (33.1) 3162 = constant
Q = flow rate (GPM)
d = ID (inches) of hose or tube
Second is finding the delta...
I have been trying to calculate the pressure drop at minus temperature using the standard pressure drop caculation through piping and hosing. What I am finding is that the calculation does not work with the Cst of mineral oil based fluids at temperatures below 32 degrees F down to -20 degrees...
