Transfill rates/procedure

[Pao]

Is there a prescribed rate and procedure for using a transfill whip? I'm looking at topping off a 19 cu ft. cylinder from an Al 80. It will just be for regular air which I will be using for non scuba use like inflating my tires and cleaning my airconditioner. I read somewhere that with compressors it should be limited to 300 psi/minute. Does this apply to transfilling also?

Thanks,
Richard

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[lowviz]

... I'm looking at topping off a 19 cu ft. cylinder from an Al 80. It will just be for regular air ...

You won't be transferring much gas if you are just topping off your pony. Open all valves slowly and you will be fine with air.

Problem is, now your 80 is a short fill. I see from your profile that you also dive sidemount. If you invest in a couple of HP tanks, you can top off your pony with the higher tank before you "even up" your sidemounts after short dives. -assuming that HP fills are easy for you to get.

Just be careful that you don't ever overpressure your AL pony.

 

[tbone1004]

300psi/minute is good because the pressure change not the volume change is what causes the heat to build. You can fill faster than that and most people do, 500psi/minute is a bit closer to real world fill rates, but be aware that filling faster means it will cool off more and you will have to top off after it cools down.

 

[Scared Silly]

What T-bone said, the recommended fill rate for scuba cylinders is between 300 - 600psig/minute.

 

[nimoh]

You won't be transferring much gas if you are just topping off your pony. Open all valves slowly and you will be fine with air.

Problem is, now your 80 is a short fill. I see from your profile that you also dive sidemount. If you invest in a couple of HP tanks, you can top off your pony with the higher tank before you "even up" your sidemounts after short dives. -assuming that HP fills are easy for you to get.

Just be careful that you don't ever overpressure your AL pony.

or invest in a small portable compressor to fill tires and clean the air conditioner. The free compressed air will cover the cost of the compressor in no time.

 

[Pao]

You won't be transferring much gas if you are just topping off your pony. Open all valves slowly and you will be fine with air.

Problem is, now your 80 is a short fill. I see from your profile that you also dive sidemount. If you invest in a couple of HP tanks, you can top off your pony with the higher tank before you "even up" your sidemounts after short dives. -assuming that HP fills are easy for you to get.

Just be careful that you don't ever overpressure your AL pony.

Thanks! Steel tanks and HP fills are hard to come by here in the Philippines .

---------- Post added June 23rd, 2015 at 06:40 AM ----------

or invest in a small portable compressor to fill tires and clean the air conditioner. The free compressed air will cover the cost of the compressor in no time.

Now that is an idea . I'm just wondering if my wife will tolerate another bit of kit.

 

[Bigd2722]

Other than open the valve slowly, is there a way to check the speed of the fill with a transwhip?

 

[Scared Silly]

Other than open the valve slowly, is there a way to check the speed of the fill with a transwhip?

I have a pressure gauge on my whip. The max fill is 100psi per 10 second. So I just watch the gauge and count.

 

[Pao]

So it looks like I need a gauge. I bought one without a gauge. Can I add one? Maybe using a street "T"? It is a Global one from DRIS: Global Manufacturing Tank Fill Whip | Dive Right In Scuba - Plainfield, IL - Dive Right in Scuba

 

[tbone1004]

those are just standard 1/4" NPT pipe fittings, you should be able to find the right fittings at any hydraulic shop, gauges are standard too, nothing special about them.