DIY Fill whip

[beezwax]

...but may make mixing more difficult.

How so?

I would first try adjusting the fill rate with the cylinder you are filling not the supply cylinder...

I seem to remember the OxyHacker book saying to have the fill tank valve fully open before cracking and controlling the transfer with the supply side valve (or line valve). Presumably this is so the O2 doesn't burst out of the supply tank and then slam into a closed fill tank valve. Bad. But I suppose you could tighten it down after the intial flow is going if the rate seems too high....?

 

[426Scuba]

How so?



I seem to remember the OxyHacker book saying to have the fill tank valve fully open before cracking and controlling the transfer with the supply side valve (or line valve). Presumably this is so the O2 doesn't burst out of the supply tank and then slam into a closed fill tank valve. Bad. But I suppose you could tighten it down after the intial flow is going if the rate seems too high....?

I'll give you a little background on me. I don't fill scuba tanks, but I have filled thousands of Aviation oxygen cylinders along with some mixed gas cylinder applications mostly using C02 & N2. Along with doing hydro's and working for a CO. that made compressed gas cylinder valves. So I'm no dummy or expert either. And I don't own the OxyHacker book, but I would like to see it some time I'm sure there is some great info in there.

How so?

I think if you are mixing gases before the tank your filling it would. If you are filling by pressure or weight I would say you will be ok.

It may not be the best thing to open your supply tank onto a closed valve, but I would not worry about it to much. Like I said in my other post a ball valve in your line will keep all that pressure from slaming your tank valve. If you simply crack your tank valve a little you for sure will be fine, just like what your 1st stage sees when you turn your tank on. A good quality regulator will solve these issues, but gets $$$ for the DIY'er.

 

[beezwax]

I'll be doing strictly PP filling, so I should be fine. The OxyHacker book really is a great resource. I just looked up the step-by-step and this is what Vance has to say:

"If a whip valve is fitted, the valve on the fill tank should be wide open before filling is commenced, to lessen any bottlenecks that can cause adiabatic compression. I start by checking that the whip valve is closed, then open the fill tank valve all the way, then doublecheck that the whip valve is shut, open the tank valve partway, and begin the fill using the whip valve."

I'm sure the process you describe would work as well. I just placed another McMaster-Carr order for a bunch of QDs, some different gauges, another tee and elbow, and a 580 inert gas connection...so I can be completely modular and interchangeable. Nearly doubled the price, but no more whip envy!

 

[guruboy]

also look at http://www.scubaboard.com/showthread.php?t=11290 for Roakey's whip - nicely done.

Can someone fix that link please?

 

[Johnoly]

Can someone fix that link please?

Roakey's thread is 17 years old so don't know how useful it is,,,,,but here a current working link to it.
DIY Mixing Whip

 

[guruboy]

Roakey's thread is 17 years old so don't know how useful it is,,,,,but here a current working link to it.
DIY Mixing Whip

Thanks