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double yoke manifold with isolator

Posted: Tue Aug 29, 2006 6:41 pm
by standingup
back the the 60's there was a manifold with a yoke on each end that also had an isolator valve . does anyone know where these can be found ? are they still available. The advantage was you could field convert double into singles and vice versa, while fully charged---
thank you for any advice or suggestions

Isolator valve AKA pig tail, solid bar yoke

Posted: Tue Aug 29, 2006 9:34 pm
by 21
Your sketchy description is some what difficult to understand.

Could it be a 'Pig tail"? which was later called a "Solid Bar Yoke?"

The Pig tail received it's name from the pig tail shape in flexible bar that connected the two tanks.

The solid bar yoke was as described a solid bar connecting two tanks.

There was a yoke on each end tha connected the tanks which had a provision in the middle for attatchment of a regulator.

The later models had a removeable fitting for a SPG which entered under the valve opening.

21

Posted: Tue Aug 29, 2006 10:24 pm
by pearldiver
I had one of the 'pig tails' for years on my twins. I heard they were dangerous one day because of the small diameter pipe. The loop was easily bent and if you bent it so many times, it weakened it. I would stick with the newer manifolds to make a twin set up and if the 'pig tail' is what you remember. I wouldn't use it.

Posted: Tue Aug 29, 2006 10:35 pm
by standingup
I believe you nailed it. However the one I used also had a isolator valve at either end so you could turn off either tank with a yoke style connector in the middle I have to admit it looked kind of rinky dink- so I'm not really sure if it was homemade.

Posted: Wed Aug 30, 2006 3:51 am
by Nemrod
I have never seen such a thing. I cannot imagine why an adapter would have a valve at each end when it had a tank valve there as well. I cannot even imagine what it might look like. The more common type adapter that converted singles to doubles with a center outlet are known for being trouble and not particularly strong or durable or reliable.

I think what you really need is a Sherwood double post manifold. These have a center outlet and an outlet on one side or the other depending on which way it was flipped--it is even possible to have three outlets by canibalizing one. The outlets could be isolated but not the tanks one from another. I learned about these from SeaRat and have become a big fan of them. They are often on ebay for 30 to 100 dollars.

Nemrod

PIG TAIL & SOLID BAR YOKE--O2 CENTER

Posted: Wed Aug 30, 2006 6:33 am
by 21
["standingup"]I believe you nailed it. However the one I used also had a isolator valve at either end so you could turn off either tank with a yoke style connector in the middle I have to admit it looked kind of rinky dink- so I'm not really sure if it was homemade.[/quote]

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I think you are referring of two O2 valves on the end with a normal scuba center. The scuba center with fit the O2 perfectly with out modification and were considered safe to use

Very common adaption in the 50s and even up to the 60s. Generally seen with twin--aka double 38 and or 60 Cuft surplus O2 tanks which had been adapted for scuba diving.

21

Posted: Thu Aug 31, 2006 3:05 am
by YankDownUnder
I think what you are thinking about is the Sherwood manifold. It is not really an isolator. It has a center yoke that can be closed seperately from a pillar valve on one side and has a J valve on the other side. It allows guys like us to install a double hose regulator in the center and a single hose regulator on one side. In that way you can dive twin tanks, with an unmodified double hose regulator, and have all the bells and whistles coming off the single hose regulator.

Nemrod also made a twin manifold like that, except it is a solid piece. Because of that, it will not allow much flexibility with regulators. If you put a double hose in the center, a number of single hosers won't fit. I have a Nemrod, but for practical application and ease of use, I would choose the Sherwood. They come up on ebay and sell for about $100.

Manifold

Posted: Thu Aug 31, 2006 9:24 am
by clevelanddiver
Vintagescubasupply.com has one for sale. $50.

http://www.vintagescubasupply.com/access.html

It is towards the bottom of the page.

Isolator valve--Pig tail? O2? Sherwood ?

Posted: Thu Aug 31, 2006 9:30 am
by 21
["YankDownUnder"]I think what you are thinking about is the Sherwood manifold.]

The Sherwood was introduced much later. Matter of fact it is of rather recent vintage

The gentleman is inquiring about a valve made in the 1950-1960s-- and from his description I am not certain that he know what he is asking about.

The joy of it all!

21

Re: Isolator valve AKA pig tail, solid bar yoke

Posted: Fri Sep 01, 2006 2:36 am
by duckbill
21 wrote:


The solid bar yoke..................................later models had a removeable fitting for a SPG which entered under the valve opening.

21
Those guys!..........Do you mean to tell me that that plug bolt which says "DO NOT REMOVE" can be removed after all? I figured it was just a machining access port or something. Why the heck didn't they just stamp "SPG HERE" or "GAUGE HERE" or somesuch on that bolt?! Jeesh!

Re: Isolator valve AKA pig tail, solid bar yoke

Posted: Fri Sep 01, 2006 10:11 am
by 21
[quote="duckbill
Do you mean to tell me that that plug bolt which says "DO NOT REMOVE" can be removed after all? I figured it was just a machining access port or something. Why the heck didn't they just stamp "SPG HERE" or "GAUGE HERE" or somesuch on that bolt?! quote]
____________________________________________________________

As they say at the fast food counter Quien sabe? Who knows?

It possibly could have been a machining port

I never removed mine, but I have seen it removed and replaced by a SPG. I don't recall if an adapter was required or not. In SoCal we had many large aerospace companies and they had many machinist who made all sorts of adapters under the guise of a "G Job"

Clevland diver--$50.00! what is that bar yoke made out of--gold? It appears used and abused to me--certainly not worth $50.00 hard earned yankee dollars.