Skipping Hydro

[imwright1985]

So, does DOT say you must have one, two, or three tail lights? Because I'm pretty sure that the rule is that a car must at least be equipped with what was originally on the car when it was manufactured. I had a 1942 slat grill Willy's jeep that only had a left tail light and no seat belt. Perfectly legal. Same for my 1964 Kaiser M151 MUTT. I believe Model Ts had the same thing. Now cars are made with three tail lights, but you cannot go to two, or even one tail light without being cited. I don't think anyone is cited under USC for a tail light infraction. I'm 99% sure it is under CVC. So much for DOT regulation. LOL!




"Pressurized time" has nothing to do with it. The rest of your list is good though. The main element outside of environmental factors is cycling, and the degrees to which the steel has been stretched in that cycling. Time itself is not a factor. You could fill it once for one hour in a five year period, and the result would be the same as if you had filled it once and left it filled for the entire five years.

That depends on year for vehicle to fall under certain dot regulations, same with EPA, I guess you have had better luck then me because i had a 1976 corvette with true dual exhaust and no cat (florida we dont have emissions inspections) and reproduction taillights(not dot approvedto save i think it was around 100 bucks). I got pulled over for noise ordinance which was kinda expected and the cop was a total jerk(knew how to cite me for everything really good) and cited me for all of it. anyways long story short had to fight to get the car back, pay around 900 in fines and had to change exhaust and tail lights within 10 days of getting car back.

Also pressurized time has a slight effect on it because the material is under load for what ever time its filled allowing the Grain deformations more time to occur. Also that every temp change the load for the material increases/decreases with some exponential function near what the "max working load" is for that tank which higher the pressure the more critical it is. Take a basic Metallurgy class and you will learn all about the effects of loading alloys with stresses.

 

[drbill]

Not sure what a hydro costs there, but it's only about $35 here ($7/year of service). I find that a very small cost to better ensure your safety. I've had TWO HP120s fail in two years.

 

[fire_diver]

I've got a 1/2" ST72 last hydroed in 1958 still with air in it. I haven't drained it yet because no one will fill it even with a hydro and I don't want it to rust. I guess I could get one more dive out of it...

That's insane! What reason could they possibly have for not filling a steel 72? There are hundreds of thousands of tanks in use that are older than that. I've seen original hydro dates from the 30's and 40's on some storage bank tanks.

 

[DaleC]

It's the 1/2 inch neck. I had one guy say he "might" but I'm not holding out any hope. I plan on getting it hydroed and then trans filling with a whip but I have to figure out the valve (rebuild kit) and get a whip first.
Unlike some parts of the US there isn't a big vintage community around here to draw on and the shops frown on old stuff.
I wish Captain lived next door :depressed:

 

[fire_diver]

So are you needing a valve for it, or are they just refusing to fill it based on age?

 

[captain]

It's the 1/2 inch neck. I had one guy say he "might" but I'm not holding out any hope. I plan on getting it hydroed and then trans filling with a whip but I have to figure out the valve (rebuild kit) and get a whip first.
Unlike some parts of the US there isn't a big vintage community around here to draw on and the shops frown on old stuff.
I wish Captain lived next door :depressed:

A little too cold for me so don't expect me to move in next door anytime soon.
What brand valve is it. If it still holding air there can't be much wrong.

 

[duckbill]

It's the 1/2 inch neck. I had one guy say he "might" but I'm not holding out any hope.

Wah, waaaaaah! 1/2" valved cylinders have been visualled for DECADES, and now the crybabies are all spoiled by the 3/4" valves. I suppose if cylinders came out with 1" valves, the shops would eventually whine about the 3/4" valves. WAH!

Dale, I hope you can find a shop that can help you with your cylinder. Dive shops that don't cater to divers should not call themselves "dive shops".

 

[duckbill]

Also pressurized time has a slight effect on it because the material is under load for what ever time its filled allowing the Grain deformations more time to occur. Also that every temp change the load for the material increases/decreases with some exponential function near what the "max working load" is for that tank which higher the pressure the more critical it is. Take a basic Metallurgy class and you will learn all about the effects of loading alloys with stresses.

Infinitesimal. Hardly worth worrying about or discussing for any practical purpose. Just be sure to turn the cylinders every once in a while so the microcrystallin steel grains don't align with the electromagnetic fields of the earth.

 

[SparticleBrane]

Not sure what a hydro costs there, but it's only about $35 here ($7/year of service). I find that a very small cost to better ensure your safety. I've had TWO HP120s fail in two years.

Your tanks failed because the boats you were diving off of gave them nasty fills full of moisture, and you didn't catch it. But you continue to harp on it, and how it is obviously PST's fault that they rusted due to the presence of moisture in the cylinders.



Everyone here keeps quoting statutes and talking about cops pulling you over for tanks...


Someone PLEASE find me ONE case of someone getting cited (and fined, and convicted) for carrying SCUBA cylinders out of hydro, or across state lines, or whatever. Please. Cops have bigger things to worry about, like that useless war on drugs, people speeding, murderers, rapists, illegal aliens, etc. They could care less about your diving cylinders.

 

[DaleC]

A little too cold for me so don't expect me to move in next door anytime soon.
What brand valve is it. If it still holding air there can't be much wrong.

I was going to pick your brain about this soon anyways Captain. I am under the assumption that, after so long, I would have to rebuilt the guts. It is a square valve with a top mounted butterfly nut. The body reads:
Healthways Scuba
LA Calf.

Superior
5871