Vintage doubles - worth it?

[duckbill]

The stampings on the tanks show only the original Hydro, so I should be able to get a "+" rating again when I have them hydro-ed ... right?

You can get the + at any hydro as long as the original factory hydro shows a +. It does not matter if the + was skipped a hydro or two or three.....

The problem will probably be to find a hydrotester who will properly + your tanks these days, especially if you do not have an REE number for your specific tanks.

I modified a rope light to fit in my cylinders for inspection. Works great, but you have to be carefull using full 120 Volts inside a metal tank.:shocked2:

 

[SwimJim]

I bought an inspection light from harbor freight. Cost about 8 bucks if I remember right.

 

[HenrikBP]

I've had good luck with the small, white Christmas lights.
<snip>
Please let me know what you come up with. I don't think my backpack was originally made for doubles.

Very nice looking tanks. I'll give the Xmas lights a try ... and be careful of the 120V - yikes. I think I'll go with new bands. When I got mine off, it was clear that both "bridges" had slipped in some fashion. So while they could no doubt be welded and buffed up, that might be a project for later.

Turned out the backplate was crushed in one corner, so I may try to find a way to use my Freedom plate instead. Maybe some carriage bolts will work.

You can try, it might be a trick. Having just the original hydro doesn't have anything to do with it, you need to know the REE number. Those are Norris tanks, correct? There is a document floating around with PST REE numbers, but I don't know anything about the availability of norris REE numbers. There is a way to calculate it, but good luck finding a hydro guy that will do that. Around here, it seems most of the hydro guys are only the second or third generation in their families to walk upright.

I think someone at the beginning of this thread mentioned that Healthways got their tanks from Norris, but I don't know. I'll look for the document or a way to calculate the REE #

You can get the + at any hydro as long as the original factory hydro shows a +. It does not matter if the + was skipped a hydro or two or three.....

The problem will probably be to find a hydrotester who will properly + your tanks these days, especially if you do not have an REE number for your specific tanks.

I modified a rope light to fit in my cylinders for inspection. Works great, but you have to be carefull using full 120 Volts inside a metal tank.:shocked2:

That's good to know. I thought you could only get the "+" for the first 2 hydros. A friend of mine knows someone who does hydros, so I'm hoping I can talk the guy into doing it right.

I bought an inspection light from harbor freight. Cost about 8 bucks if I remember right.

Of course - Harbor Freight. Dangerous to start browsing their stuff. I always end up buying for 3 times more $$ than I originally intended

Thanks guys,

Henrik

 

[HenrikBP]

Well, the Home D rope light "kinda" worked. As far as I can tell the cylinders are clean inside, but with some dark "dust" in the bottom. I have a difficult time judging the color of the inside of the tank due to the yellow color of the light, so I'll look for an LED version.

I'm unfortunately also striking out on any kind of information about the Norris tanks REE numbers. If anyone has that information I'd appreciate it. I found Norris Cyliders and am guessing that's the company that made the tanks. I'll get in touch with their customer service and see if they still have REE info for these tanks.

I noticed that the sealing o-ring has a square cross-section. Is that a shape that's currently available, or can I just use the round tank valve o-rings that are currently in use?

Thanks,

Henrik

 

[Luis H]

I have been calculating specific REE numbers for all my 3AA tanks (14 steel 72’s and two sets of twin steel 45's).

I happen to have access to precision ultra sonic test equipment that can measure the wall thickness to 1/1000 inch (or better). This has allowed me to do precise REE calculations.

The way I read the codes, if I have data from three tanks of a class (from the same manufacturer) I can use that data to calculate an REE for that class of cylinders. This comes from the CGA manual that is invoked by CFR49 (Code of Federal Regulations).

I not only need the wall thickness, but I also need precise internal volume (which I get by filling them with water and measuring the weight precisely), and the hydro data.

At this point I have all the data needed for only one of my Norris steel 72’s, but in a couple of month I will be hydro testing three more Norris tanks (and one PST). At that time I should have enough data for that class of Norris tanks.

That being said, I have no idea if your hydro station would accept my calculations.

The REE number for the Norris tank that I have tested is 61.2 cc.
The REE number for two PST tanks that I have tested came out to be 61.5 and 58.7 cc.
The published REE number from PST is 58.4 cc. As expected, that would be a more conservative (lower) number that the number calculated for a specific tank.

If you can get some information from Norris that would be good.

 

[Luis H]

I noticed that the sealing o-ring has a square cross-section. Is that a shape that's currently available, or can I just use the round tank valve o-rings that are currently in use?

Thanks,

Henrik

The O-ring got crushed into that shape. replace it with a regular tank O-ring. It is probably not really square, the cross section is more like a triangle.

 

[halocline]

I noticed that the sealing o-ring has a square cross-section. Is that a shape that's currently available, or can I just use the round tank valve o-rings that are currently in use?

Thanks,

Henrik

It's a shape that is currently available if you get your o-rings off of a used tank that hasn't been inspected in years

 

[HenrikBP]

I have been calculating specific REE numbers for all my 3AA tanks (14 steel 72’s and two sets of twin steel 45's).

That's a lot of great information. Thanks Luis. I can to a degree understand why hydro operators shy away from calculating REE if they don't have to. Of course they could offer to do it and name their price.

I'll try to contact Norris today and will report back.

The O-ring got crushed into that shape. replace it with a regular tank O-ring. It is probably not really square, the cross section is more like a triangle.

Thanks Luis. The O-rings look so perfectly square that I thought they'd have to have started out that way.

It's a shape that is currently available if you get your o-rings off of a used tank that hasn't been inspected in years

Thanks Mattboy

Henrik

 

[HenrikBP]

I heard back from Norris Cylinders (TX) today. They apparently split off from Norris Industries in CA years back, and don't have any records of these older cylinders.

The gentleman I spoke to was very helpful - and it was nice of him to get back to me considering

In short, he referred me to CGA document C5 which gives 2 ways to calculate REE - essentially what Luis did. Other than time/cost it seems that the ultrasonic measuring of wall thickness is the big catch for the hydro facilities.

So I'm back to square one but will keep digging. I'll also contact the Hydro guys and ask if he would accept Luis' numbers when he gets them.

Thanks again,

Henrik

 

[HenrikBP]

OK, so next question:

At this point I won't go "true Vintage" but want to dive my PRAM in an "eclectic" set-up

I've read Luis' thread about his double hose "Tech" set-up and would like to do something similar. It seems that I'd need a Sherwood Dual Outlet manifold with the valves "reversed" left to right so that the left post outlet is facing back. Is that correct?

Do those manifolds pop up on eBay or VDH classifieds?

Will modern tank bands work, or does the Sherwood manifold provide a different tank spacing?

Thanks,

Henrik