Doubling Steel 72s

[GForceV]

I've been considering doubling a pair of old steel 72s for quite some time now (I don't have any at the moment) and have just a couple questions. First, what is the thread information or various threads that could have been used on the old models of steels 72s? Is it the standard 3/4" 14 NPSM used on most tanks now days or something different? Basically, could I use a standard 200 bar manifold or do I need something special? Also, where are the best places to find high quality 6.9" bands and which manifolds would those bands work with? Thanks for the help! Look forward to some good answers!

 

[Ltstanfo]

Banding up steel 72s is easy and a relatively inexpensive way to get more back gas. Steel tanks have been around for a very long time (since the mid 50s if I recall correctly). Any steel tanks you find with a "born on date" from the mid 60s or later will use the current thread standard and therefore can accept a 200 BAR manifold without problem. Finding bands may be an issue depending on where you are. Recall that steel 72s are 6.9in diameter tanks. You can use 7in bands. There are new production 6.9in bands available on ebay and from vintagedoublehose.com.

I think twin 72s are great. I have two sets of them and routinely use them for quarry diving as well as ocean diving. Have fun and enjoy!

Regards,
Ltstanfo

 

[GForceV]

Any one have any other ideas on where 6.9" bands can be bought? Thanks in advance!

 

[captain]

Vintage Repro. New Stainless Steel Scuba Tank Bands - eBay (item 190452508842 end time Oct-11-10 10:16:52 PDT)

 

[Ltstanfo]

I should have added that you can occasionally find NOS highland mills bands, etc.. in 6.9in on various internet shops and in local dive shops but I think that all the major producers have quit making them. Most people don't want to seem to bother with steel 72s these days and I guess the retail market isn't lucrative enough to continue to support them.

Regards,
Ltstanfo

 

[formula1mb@aol.com]

I've been curious about trying a pair of doubled 72's too. Figured it's a good way to try doubles with reasonable weight and not that much heavier than an HP 130 or 149.

If I wanted to use an isolation manifold, any 200 bar modern manifold would work? Any good place to buy them with the correct spacing for twin 72's?

 

[cool_hardware52]

I've been curious about trying a pair of doubled 72's too. Figured it's a good way to try doubles with reasonable weight and not that much heavier than an HP 130 or 149.

If I wanted to use an isolation manifold, any 200 bar modern manifold would work? Any good place to buy them with the correct spacing for twin 72's?

Manifold spacing is not a function of the cylinders, it is a function of the center to center spacing of the bands.

Most modern manifolds are 215 mm center to center. When you source bands check to see that they are also 215mm C to C.

If your 72's have straight 3/4 threads most Iso manifolds sold today will work.

BTW, some 72's are 6.9" dia, and some are 7.0" dia. Bands for faber lp 85's are 7"

Tobin

 

[formula1mb@aol.com]

Thanks for the information Tobin! Gotta love scubaboard, get a straight answer without having to look around for hours.



Robert

 

[James S]

These are the bands I use on my double 72s.

Dual Tank Bands Piranha Dive Manufacturing

 

[waterpirate]

I just bought two sets of steel 72's to use for shallow stuff, when my hp 100's were gross overkill an gas amount. Also the lp 72's are a good place to put the last of the he that I used to send back.
Eric