Getting European 6.3" c-t-c isolator bars on U.S. tanks

[MichaelMc]

Will some European isolator bars thread properly into U.S. DGX valves? Such as European Apeks, BtS, or DirZone? Those come in the short 6.3" or 6.1" spacing I'd like to try with my tiny doubles, with suitable bands.

The DGX valves share modular plug compatibility with "Dive Rite, Edge/Hog, Halcyon, Hollis, Sea Elite, and Thermo". So compatibility seems likely. But the DGX are not compatible with "Blue Steel, OMS, and Sherwood". DGX Modular Valve Port Plug, Plain (Normal Threads). Beyond threading and o-ring, how deep the threading and o-ring surface starts could be an issue.

The BtS and dirdirect 'generic' isolator bars look very similar to the DGX isolator I have. Square center profile then a round section if they're wide. Which suggests they may be made in the same place. Not that there are that many shape possibilities. The spacing of the threaded section and distance to the o-rings look similar. The Apek length of threading and o-ring look similar, but have a round body. The threading seems the main unknown.

Any suggestions between dirdirect, xpertdiver, 4thelement-diving.co.uk, or others for sourcing if some are compatible?

I have tiny 5.5" doubles with normal U.S. 8.5" separation and DGX valves. Yet I'd like to try the narrower 6.3" European separation. It trims an inch from each side of the stuff-on-my-back. I know I can just dive them as independent doubles, but would like to do it with an isolator manifold. And I already dive tiny sidemount as well.

I believe two, machine shop adept, folks at least are playing with the freedom plate and tiny doubles. Is that with narrow, 6.3" narrow, tank separation?

 

[Akimbo]

There are two center-to-center standards for doubles with isolator valves. The most common is 215mm (8.46") and the one you need for tiny doubles is 190mm (7.48"). This site might help you figure out if your valves have a 190mm isolator valve available: Pirana Doubles Manifolds

I use them on double 45s, 50s, and 72s:

There may be some useful information on valves and assembling doubles in this thread: Scuba Cylinder Valve Installation

 

[runsongas]

the apeks/bts/dirzone are metric whereas the dgx manifold is imperial iirc. same issue you have with 3/4 vs m25 neck sizes.

 

[MichaelMc]

@Akimbo, Europe has three separations. UK Apek's has isolator manifolds for:
5.5” Cylinder, with Centers (154mm to 170mm)
7” Cylinder, with Centers (177mm to 193mm)
8” Cylinder, with Centers (216mm to 232mm)
Apeks Twin Manifold
BtS and Dir Zone have similar spaced isolator manifolds.

7L (LP50) are used with the two narrower separations, 6.3" and 7.3".
160mm 6.3" c-t-c as narrow bands for 7L (5.51")
186mm 7.3" c-t-c as wide bands for 7L (also 10l, 12l)
220mm 8.7" c-t-c for 15l, 18l, 20l

U.S. Piranha has 190mm 7.5" and 215mm 8.5". In blue steel, which they place out of the common end plug compatibly DGX claims between several brands.

As Europe has different tank threading and no burst disks, isolator compatibility seemed the easier route.

Thanks for the valve write up! I studied it several times before playing with mine, and got flag tape to protect my o-rings.

 

[MichaelMc]

the apeks/bts/dirzone are metric whereas the dgx manifold is imperial iirc. same issue you have with 3/4 vs m25 neck sizes.

Argh. Thanks. Metric on that connection was a worry. We do have some metric stuff over here....

Not sure if U.S. 7.5" c-t-c are worth it.

I saw BtS comes in US 3/4 thread, maybe with burst disks.

 

[Akimbo]

Europe has three separations. Europe Apek's has isolator manifolds for:
5.5” Cylinder, with Centers (154mm to 170mm)

Is the 5.5" an isolation valve or just a spool? I have only seen the spools but please let us know if you find a source the narrower format isolation valve compatible with US valves.

 

[MichaelMc]

@Akimbo, The 160mm 6.3" c-t-c have a knob.

DIRZONE MANIFOLD COM ISOLADOR COMPLETO - Torneiras - Garrafas e Acessórios | XpertDiver
BTS COMPLETE ISOLATION MANIFOLD | XpertDiver
Without a narrow picture but listed as isolator:
Generic G5/8 Isolator Bar

I'll let folks know if I figure this out.

 

[MichaelMc]

A partial update on building isolatable tiny doubles (AL40, LP50, 7L) with narrow c-t-c separation (about 6" vs 8.5"), in the US, with burst disks, for 3/4 NPS tanks.

Australia seems to have the same necks and burst disk rules as the US and stocks 5.9" San-o-sub manifolds, and 5.5" bands. Also, they sell a 6.5" DiveRite isolation manifold. Links and costs below.

More to follow eventually.
Any suggestions are welcome from our Ausi members, or on better sources. Or others trying this out.

It may be a bit before I venture on an Australian order or set of emails. Just before I figured out the Australian bit, I ordered 8.5" c-t-c 5.5" diam bands for my 8.5" isolator.

@Akimbo, @DanaHunt


- An Australian 'what you need to know about tanks/valves':
Scuba Diving Valves and Manifolds from The Scuba Doctor Dive Shop - The Scuba Doctor Dive Shop

# Manifold
- The Scuba Doctor has 5.90" c-t-c isolation manifolds from San-o-sub, $220-234US
San-o-Sub Dual Outlet 232 Bar Isolation Manifold - The Scuba Doctor Dive Shop
- Or, Onlinedivegear.com.au (Adelaide's) for the San-o-sub manifolds

- Techdivgear.com.au has 6.5"/165mm DiveRite Short manifolds #VA3003-232 $175US 200bar
I've emailed DiveRite asking about getting it in the US. A thread may suggest it is old stock.

# Bands
- Scuba Doctor may have narrow bands for 5.5" diam tanks, from Alpha Diving Products. The pictures look narrow, though they are not explicit on c-t-c separation. $134-188US
Alpha S/S Heavy Duty Bands w/ Rubber - 140 mm (5.5 inch) Faber - The Scuba Doctor Dive Shop
Alpha S/S Heavy Duty Bands w/ Rubber and Bridge - 140 mm Faber - The Scuba Doctor Dive Shop
Alpha S/S Heavy Duty 1-pc Bands 3/8 Allthread - 140 mm Faber - The Scuba Doctor Dive Shop
- Or, V4tec, in Germany, has 6.06" c-t-c bands, though that seems tight.

# Service Parts
- A 2018 thread suggests service kits are on eBay.
Faber (san-o-sub) 232 bar valve service kit
- Burst disks: Onlinedivegear.com.au has burst disks that are: washer+disk. small/large, standard 207-240b cylinders or HP 300b cyl. $12

# BtS manifolds
Getting US spec'd BtS manifolds via OMS/DUI-USA or Extreme-Exposure.com failed.

# Importing:
My research is under $200/800/2000, depending on customs interpretations, it just shows up at your door, or maybe your local postoffice for any duty.
- Internet Purchases | U.S. Customs and Border Protection
- Mail - What can be imported through the mail
- Mail - Goods requiring duty
- DirDirect Worldwide