Recent content by Roy S Ramirez

Hello @marcusl , thanks! I think that 6.924 mm suggested by Inventor might be that standard depth

Hello everybody! I've notice that when using NPT fittings, the female fittings usually doesn't take all of the male threads: This has never bothered me since these are commercial fittings and the engineers who designed them know what they are doing. But now, I need to make NPT holes in a...

Hello @JBA. I don't have a nozzle attached right now. I only have the injector, and yes, PT21 and PT31 are relatively close to it. (Cold flow at Zucrow Propulsion Lab two months ago) PS: I manged to fix the response time issue.

Hello everybody! I hope you are all doing well. I built a liquid rocket injector and the following feed system: I started to do hydro-static tests (cold flows) and a program I wrote records all the data for me (except for the flow rates which I measured experimentally by collecting the water...

Thank you very much to all of you. My system is meant to run for only 3 seconds perhaps twice or three times a day. I'll do my best to follow your advice!

Thanks! I'll try to get fittings that are rated for the pressures I want to deal with. But just out of curiosity, supposing the fittings are well tightened, what are the risks of flowing a fluid at 180ish psi when the max pressure is 150 psi? Could a stainless steel fitting just blow up?

Hello everybody! I bought some fittings for a feed system I'm building, and I need to handle pressures between 150 and 200 psi. I noticed some of them have max working pressures of about 1000 or 3000 psi, but others have relatively lower ones (150 psi, see...

Mmmm that could be it, but as @boneh3ad noticed, I would have to lower the pressure from 60 to around 0.5 psi to make the eqs match, and I doubt that's the valve's pressure drop :/

Thank you very much for checking it out with your MATLAB code. If the calculations seem to be right, there must be an error in my measurements I guess. But practically speaking, for a 1/2" hose (36" long) with a 60 psig supply pressure, isn't 55 or 40 gpm way too much?

Ok, I ran the experiment again with a 96 in hose this time, and I got 0.17 qt/s, whereas the mathcad says 1.7! There always seems to be a factor of 10, what's going on here?!

Ok, I'm going to try with a longer hose this time, and maybe try to get another pressure gauge. When I put my hose with a pressure gauge, it reads like 1 psi which interestingly does kind of match the equations. But yes, when I only put the gauge (without the hose), and open the valve, it reads...

@Mech_Engineer Thank you very much! I tried using the same equations you used in mathcad but I'm sill getting a similar result which is off by a factor of 10 :/

@boneh3ad Thank you very much for your reply! I think I was using the Hagen-Poiseuille equation to confirm that the flow was turbulent, but using the resulting Reynolds number for the Darcy-Weisbach is not correct, you are right. Also there should be no unit errors since the software I'm using...

I would love to just find that factor but I'm starting to think that those equations I used are not appropriate/ suitable...

@jrmichler thanks! I see what you are saying. So how would you calculate this theoretically? I used the my tap because that's what I had available, but imagine a similar case where I have a tank pressurized at 60 psi, and I connect a 1/2", 36 in long hose to it through a valve. If I open the...