DIY Fast Inflation kit???

[avius]

hey guys. I found this SCUBA tank fast inflation setup that Zodiac makes. AWESOME idea!!! I want one! As we know, Zodiac charges an arm and a leg for anything they sell. So... My question, has any of the DIYers here attempted this yet? It looks like a basic SCUBA first stage, and air lines, but it has been difficult finding the proper size fittings to attach the air line to the valve. What you guys think?

[willk]

I use a variation of this, employing a BCD inflater button for better control. Dunno about your RIB valves but mine are simple push fit affairs. I'd just build the fit up with bits of hose/pipe/tape. You won't manage three tubes simultaneously like that though. In any case, I think that's a bit risky - no control during what would be a fast fill

[avius]

The bcd button sounds like a dope setup. I didn't think about that, but glad u mentioned it cuz if I rig this up I'll definitely borrow your idea. Do you have a pic of the setup you rigged? Mine is a SIB and I was thinking that I could run a line from the buoyancy tubes to the inflatable keel, and also to the speed tubes.

[jyasaki]

Hmmm. Dumping 140psi (assuming it's a standard scuba reg Intermediate pressure) into chambers taking 3psi? And doing 3 at a time? That sounds a little dangerous.

A friend with a Zodiac Pro 15 (or whatever they call it) uses a standard scuba cyliner and reg, with one of those "flex-to-inflate" rubber nozzles with a hose protector zip tied to the flex end. The hose protector fits his valves perfectly, and the flex bit gives you pretty good control over the inflation rate. One-chamber-at-a-time inflation, though, which seems more sensible to me anyway.


jky

[m chappelow]

Normaly with fast inflation there is a diffuser on the outlet ,which breaks up the stream of gas ,otherwise with high pressure the stream of air could blow a hole in the tube before it has time to expand or cause stress on a seem if its inflated too fast ,the diffuser also stops ice pellets from forming which can shoot holes in the tube ,though i suppose some zodiac valves may act like a diffuser .though normal breathing air will have had most of the moisture filtered out unlike some gasses eg co2 /n2

[avius]

See this is y I love this forum.. Good info guys! Jyasaki, u and Willk bring up a good point about the pressure. Maybe better do 1 at a time fill ups. Since my boat is on the larger side its rarely deflated fully, and this fast inflation will be primarily for top offs once in the water. I was just trying to make the top offs easier, but not at the risk of bursting anything. What do u think about adding a Manometer into the mix. and using the SCUBA tank valve to control the rate of inflation?

Does anyone know if a SCUBA BCD inflator reduces air pressure before the air gets to the BCD? It seems like it would considering that a BCD is also an air bladder.

m Chappelow, good thoughts on the diffuser, but I think that my valves would definitely diffuse the air before it hits the tubes. see the schematic i attached

[willk]

Originally Posted by avius

Does anyone know if a SCUBA BCD inflator reduces air pressure before the air gets to the BCD? It seems like it would considering that a BCD is also an air bladder.

And this is why I like posters who engage their brains! Good man Avius

The system I have is supplying air at intermediate pressure 8-10 BAR, but is doing so via a restricted valve (the inflator) so you have lots of time to control matters. It takes a few minutes to fill a 2.6M SIB so plenty of control on a tube - you keep one hand on the inflator and one on the tube - easy peasy.

EDIT: In other words - it fills your tubes as fast as it fills your BCD on the surface - not scarily fast :-) - the catch is that it won't stop supplying air until your tubes burst...

[m chappelow]

you could always get a redundent or an old ist stage regulater and reduce or screw down the intermediate pressure to something suitable .

[jyasaki]

Originally Posted by avius

Does anyone know if a SCUBA BCD inflator reduces air pressure before the air gets to the BCD? It seems like it would considering that a BCD is also an air bladder.

No, it doesn't. The inflator, though, is simply a schrader valve (as on a car or bicycle tire valve stem) that doesn't get opened very far, so though it's still at about 140psi, it's controllable. The BCD bladder normally has an overpressure release valve as well.

I have a Bravo BST 12 electric pump; it's a combination rotary/piston pump that quickly fills tubes to 1 psi or so with the rotary pump, then switches to the piston mode and fills to either 4.5 or 11 psi depending on the model you get. The shutoff pressure is adjustable. It comes with alligator clips for battery power, but I wired mine into the electrical system. There's another model that comes with some kind of built-in battery, as well.

Topping off my boat (5.5m or so) normally takes about 3 minutes (I transport with the tubes fairly soft, then fill once I'm on the water.)


jky

[jyasaki]

Originally Posted by m chappelow

you could always get a redundent or an old ist stage regulater and reduce or screw down the intermediate pressure to something suitable .

I doubt you'd be able to adjust a scuba reg below about 75 psi, unless you start mucking around with replacement springs and stuff. Might be wrong, but they're designed to supply 120 to about 160 psi on the low pressure side.

jky