Estimate time to Pressurize a Tank 1

[pk22]

I'm trying to determine estimate times to pressure up a volume filled with water.

I have a positive displacement pump with a volumetric flow rate of 10 gpm, and I have a set volume 35.3 ft³.

For this I'm assuming my pump is connect directly to the tank, no piping losses, the system is already completely filled with water, and my starting pressure is 100 psi.

I need to figure out how long it would take to raise the pressure to 10,000 psi.

 

[TiCl4]

Look up bulk modulus or compressibility factor of water if you want a more accurate calculation. A rough estimate is 0.36% of the volume per 1,000 psi, so 3.6% of volume for 10,000 psi. So for your 264 gal tank, that's 9.5 gallons for 10,000 psi, or roughly a minute.

I'm curious as to the design of the tank. 10,000 psi is quite a lot for a vessel that large. The application I am familiar with (high pressure water) has only piping after the pump.

 

[LittleInch]

Have a look at this and adapt for your purposes.

You also need to factor in the expansion of the vessel. That's usually similar or close to the bulk modulus volume

but agree with TiCl4 - 10,000 psi??? Are you serious? Tell us more.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[pk22]

Thanks for the information, it's not for an actual tank, it's for pressuring up a system, I assumed providing a simplified scenario would benefit in receiving answers. You got me on the right track, so it is greatly appreciated.

 

[pk22]

LittleInch I don't see any attachment or link, is there something I'm missing?

 

[LittleInch]

Sorry, forgot to paste this FAQ.

https://www.eng-tips.com/faqs.cfm?fid=1339

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[IRstuff]

I need to figure out how long it would take to raise the pressure to 10,000 psi.

Is this something that your pump can do? If it can't generate 10 ksi, then it ain't going to happen. I was going to suggest heating, but LI beat me to it and provided a solid link.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[1503-44]

Expansion of 35 ft3 isn't going to be all that much. Water compression neither. Bulk mod at 10ksi is 400,000 psi, about 2.5%

Assume the vessel is 10 ft of 36"od pipe with a 7" wall. 52 ksi DF = 0.5 with that wall, expansion is nil.

27.5 minutes ... hell, give it 30.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[dik]

Neat question... thanks.

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So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[LittleInch]

It's 1 m3 of what I assume is API 5000 wellhead equipment. That doesn't get very big diameter.

So yes it won't expand much compared to thinner pipe.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[r6155]

I assume you did the hydrostatic pressure test, right?

Regards

 

[pk22]

From TiCl4 reply I got the calculation I was looking for, from looking back in my old fluids text book I came across:

K = -ΔP/(Δv/v), using the approximation of 300,000 psi for K for water, I can then determine my approximate change in volume, for the require volume I needed to fill. Now I understand this doesn't account for expansion of the system components, it's not an actual tank we're pressuring up. However this give's a rough idea for our application.

IRstuff - Yes my pump used is capable of handling 10,000 psi, we're using a triplex (plunger style, positive displacement pump).

r6155 - This is all hydrostatic, no air in the style.

 

[r6155]

@ pk22
You are somewhat confused. Hydrostatic testing is a slow increase in pressure, step by step, and inspections during the test.
Have you read ASME VIII?

Regards

 

[georgeverghese]

If there is a discharge pulsation bottle at the pump, say some 80% of bottle volume should be included in the calc also, since almost the entire bottle will be empty when bottle pressure is 100psi.