Older steel tanks

[spectrum]

Now being that I have an engineering degree the logic behind why they call them 7/8" makes no sense and just adds to the confusion.

The common 3/4 inch cylinder thread in use today is a straight pipe thread. If you are of an appropriate engineering discipline you will realize that pipe threads are sized based on the ID of the pipe making for a large thread for a given trade size.

For some reason beyond me the early PST HP product that you have received a UNF (like nuts & bolt) thread which is dimensioned to essentially the major diameter of the male (valve).

That is why the 7/8 valve is smaller than the 3/4. They are two very different thread formats.

FWIW I have 4 of those cylinders in the collection and they are very nice. For all intents and purposes they are comparable today's X-100 that has a going rate of $350. Between purchase and test fees you should have a bargain there. They are of course DIN only animals but if that works for you then you're good to go.

Pete

 

[Scoobers]

Thanks for the explanation on the measurements. I went to school for welding engineering so I learned nothing about threads as it is not something I deal with. These tanks are going to be doubled up and used for taking my tech training. After every thing is paid for I will only have about 400-500$ into a set of 100 cuft doubles. Not to bad.

 

[oxyhacker]

There is a huge difference between a facility giving you a vague verbal assurance that they "are familiar with these older steel tanks" and a facility actually having and being familiar with PST Bulletin D100. Too often, the difference between the tanks passing and being condemned. Too late to worry about this time, but keep it in mind for next hydro.

They are 100s and I dropped them off at the LDS for hydro and they were familiar with these older steel tanks. Now I just need to find manifolds.

 

[Superlyte27]

I just picked up some older (1992) HP steel tanks off of craigslist for $100. I want to double these up but I am having a hard time finding 1/2in valves. If anyone has any suggestions on where to get some half inch valves let me know.

Hey, I just saw a manifold set for this last week. The rebuild kits for orings and stuff are expensive, but if you want them, send me an email Wednesday and I'll send you some pictures and figure out a price. I'll make them cheap.

mccumb4@gmail.com

 

[kierentec]

I am also searching for a manifold with the 7/8" thread. Please let me know what you find. Northeast scuba supply is all out, of course.

 

[rx7diver]

I just picked up some older (1992) HP steel tanks off of craigslist for $100. I want to double these up but I am having a hard time finding 1/2in valves. If anyone has any suggestions on where to get some half inch valves let me know.

Scoobers, I have the "original" manifold for these tanks. It was called a "Sherwood Genesis Double-DIN Isolator" manifold. I purchased it new c. 1993 to double up a pair of HP 100's using a pair of the original Dive-Rite bands that were manufactured for this configuration.

I used this set-up for 5 or so years, and then switched out the HP 100's for HP 120's, the set-up I used for another two or so years. I then switched out these manifold and bands for OMS manifold and bands on these HP 120's, the set-up I still have.

I used these set-ups for Great Lakes technical diving when I was living in Michigan. In particular, they have never seen salt water.

The Genesis manifold has remained sealed in a zip-lock bag in my equipment room for several years! The 4 O-rings in the isolator assembly (2 on each end of the isolator) will need to be replaced, I think; IIRC, I pitched these just before I stored away the manifold. And the tank-to-valve HP O-rings and the burst discs "should" be replaced, of course, which would generally be done when your doubles set-up is hydroed and VIP-ed.

IIRC, the cosmetic appearance of the manifold is excellent. (I try to keep all my gear in excellent condition, usually.)

Would you be interested in this/these old, long-unused manifold and/or bands?

Ronald

 

[rx7diver]

Just remembered that I showed the Genesis manifold and and Dive-Rite tank bands on Scubaboard in an earlier post, viz. #22 here: http://www.scubaboard.com/forums/solo-divers/252248-baby-doubles-steel-55-cf-3.html#post3840834 . In the photos, they are sitting at the foot of the HP 80's, the small blue tanks on the left. Let me know if you want better photos.

 

[rx7diver]

Just remembered that I showed the Genesis manifold and and Dive-Rite tank bands on Scubaboard in an earlier post, viz. #22 here: http://www.scubaboard.com/forums/solo-divers/252248-baby-doubles-steel-55-cf-3.html#post3840834 . In the photos, they are sitting at the foot of the HP 80's, the small blue tanks on the left. Let me know if you want better photos.

Scoobers (and others), the thread is in the "Solo Divers" forum (go to main Forums page, scroll down to "Technical Diving Specialties", click on "Solo Divers", search for "baby doubles" to find the thread). One thing though: You might not be able to open the photo unless you're a member of that forum.

BTW, the early Dive-Rite bands were NOT substantial by any stretch of the imagination. They seem positively flimsy by today's standards. I think you'll find them underwhelming.

About pricing: I really hadn't thought about selling the manifold (or the bands) until I read the initial post. I'm not sure what price to ask. I just grabbed my "book" of receipts: Manifold was purchased new in August 1995 for $415 + Tx. Still looking for receipt for bands. Found it! Dive-Rite SS bands & bolts were purchased new in Sept 93 for $59 + $14 + Tx.

Photos are attached below. I googled and found the service manual here: http://www.divesafety.net/files/CylinderValves.pdf . The O-rings I referred to above are parts #13 and #15 on page 14 of this manual. Turns out I didn't pitch all of them after all. Three of them are still in place, the fourth is gone. All four should be replaced, I think.

 

[rjack321]

Unless you can find a used manifold, you are better off making these 3500psi tanks singles or selling them and getting 3/4-14 valved 3442psi steel tanks for the doubles. 7/8" manifolds (and even single valves) are stupid expensive.

 

[rx7diver]

Photos of Sherwood Genesis Double DIN Isolator valve have been added to post #18. Also, a link to the service manual for this valve has been added.

Scoobers, I really don't know what a reasonable price is for these items, so I'll just throw something out here: $300 for manifold, bands, and bolts, and buyer pays shipping from central Missouri. (The OMS manifold, bands, and bolts I purchased new in 2000 from LLoyd Bailey's totaled $375, though by that time many more manufacturers were offering manifolds to fit Genesis set-ups; when I purchased the Sherwood manifold and Dive-Rite bands c. 1995 for $490 + Tx, I think there were fewer of these types of manifolds, and so the price was very high.)

(Something tells me I should have been a bit more deliberate about all of this and listed these in the SB Classified.)