Doing hydro and visual separately

[Scuba-74]

I picked a couple of Faber 72 3000+ tanks the other day, and now considering what to do with them. They need both hydro and viz. They do have some air in them. If I decide to keep them and use either for myself (as singles or doubles) or my kids, I probably will just drop them at my LDS and get them hydroed, vized, and filled.

However, if I decide to sell them, I'm considering getting them hydroed first for piece of mind. So I have a few questions to understand the process better:

1. If I go to a place that just does the hydro, but not viz and fills, do they return the tank with the valve attached or removed? Or do they let you choose? (I assume they remove valve for testing)

2. I know that storing tanks empty introduces the risk of moisture getting in. So is it a good practice to get them hydroed and then keeping them for an unknown period of time until I either sell or decide to get them vized and filled?

 

[tbone1004]

@Lake Hickory Scuba did a great video of their hydro shop which will help you get a better understanding of the process.
they are doing a single cylinder at a time which is not always done depending on the size of the shop. The shop I use in North Carolina is quite large and you can see several SCBA bottles hanging from the spuds here. The spuds adapt the tanks to the quick disconnects for ease of filling and pressurization.

So.
1-yes the valve comes off. They should be returned with the valve on, though are not torqued and rarely filled unless they have a scuba adapter for some reason. If you bring a scuba to SCBA adapter with you and ask them to fill it, I'm sure they will.
2- they are vip'd already though don't have a stick. I'd either throw a vip sticker on there and transfill out of another tank so you don't have to deal with an annoying dive shop just tell them you lost the stick *though many hydro shops including mine do have their own air stickers*, or bring the above scba adapter so they can fill them for you, or make friends with your local fire department and fill from their scba compressor

 

[Scuba-74]

Thank you, I have not considered the SCBA->scuba option, I guess I just assumed that "no fills" means "no fills" for a random dude from the street Besides I don't have neither SCBA->scuba adapter nor the transfill hose, and having to purchase either of those makes a strong argument in favor of just going to the dive shop and doing the whole shebang.

So if the the valve is not torqued, is it safe to fill and most importantly sell to someone?

 

[JackD342]

There are a lot of dependencies here. If you are shipping cylinders, you will need to remove the valves. Compressed air is hazmat.
If local, you are probably fine. Hydro providers don't all run their businesses the same way. Mine wants all valves and boots removed before they ever get the tank.

Remember the hydro is every 5 years. So if you have one done, then sit on them for a year or so before selling them, your investment in that hydro is devalued. I would have the visual done now though if you are thinking of offering for sale, so you know if that (usually?) less costly procedure is passed. I always do a vis before sending a cylinder to hydro. Whether pass or fail, the hydro place gets paid once the work is done, and I don't want to run up any avoidable expenses for myself or my customers.

And please DO NOT try to fill any cylinder where the valve has not been properly reinstalled!!!

If you just want to put them into storage, your LDS may be cooperative about just adding 100 psi to them even though out of date. I think that is still technically out of bounds though. So if they have pressure in them now, leave it there until you decide what to do.

 

[tbone1004]

So if the the valve is not torqued, is it safe to fill and most importantly sell to someone?

Valves are not normally torqued with a torque wrench. If they don't have a VIP sticker, the dive shop who does the VIP is going to take the valve off anyway.
The big thing is that these shops don't always have new o-rings for scuba valves so you need to change that first before filling. Again, if you take it to a dive shop, when they do a VIP they do or should change the o-ring. Always ask for your old o-rings back if they don't do it as standard as proof that it was done properly

 

[JackD342]

Valves are not normally torqued with a torque wrench. If they don't have a VIP sticker, the dive shop who does the VIP is going to take the valve off anyway.
The big thing is that these shops don't always have new o-rings for scuba valves so you need to change that first before filling. Again, if you take it to a dive shop, when they do a VIP they do or should change the o-ring. Always ask for your old o-rings back if they don't do it as standard as proof that it was done properly

To clarify, one does not need a torque wrench to apply torque.

Most valve manufacturers spec 40-50 foot-pounds. Yes, some folks might use a big wrench, a mallet, and an "experienced touch." I can't speak to how much torque that method applies, or how critical the 40-50 spec is. I instead choose to use a torque wrench.

I do believe that hand tight is not acceptable.

 

[tbone1004]

To clarify, one does not need a torque wrench to apply torque.

Most valve manufacturers spec 40-50 foot-pounds. Yes, some folks might use a big wrench, a mallet, and an "experienced touch." I can't speak to how much torque that method applies, or how critical the 40-50 spec is. I instead choose to use a torque wrench.

I do believe that hand tight is not acceptable.

crow foot with appropriate adjustments done since you throw the lever arm off I hope?

 

[JackD342]

crow foot with appropriate adjustments done since you throw the lever arm off I hope?

Apply the crowsfoot at 90°, not inline. At that point the variance is immaterial.

If you want to use it inline, here is a simple converter I found AFTER I built a formula in Excel. This tool confirmed my Excel formulas were correct.
Torque Wrench Adapter Calculator - CNCexpo.com

With little effort, you can find some free downloadable apps, too.

Thought you had me, didn't you?

 

[tbone1004]

Apply the crowsfoot at 90°, not inline. At that point the variance is immaterial.

If you want to use it inline, here is a simple converter I found AFTER I built a formula in Excel. This tool confirmed my Excel formulas were correct.
Torque Wrench Adapter Calculator - CNCexpo.com

With little effort, you can find some free downloadable apps, too.

Thought you had me, didn't you?

you'd be surprised at how many people it does get....

 

[JackD342]

you'd be surprised at how many people it does get....

No, not at all surprised. I get blank stares if I try to explain the concept. You need to cite the numeric torque increase with the extension to make an impression, and get someone to care. Well, most folk.