Hard line 02

[glassblowingBiker]

so yes i did do a search for this but didnt come up with to much Im wanting to know if there is any thing other than copper pipe that can be used to hard line in for liquid o2 its the cost thats keeping me away from that thanks Jeff

[MPGB]

I'd say spend the money and do it right. Copper will last you long time. Plus you won't have to worry too much about debris and corrosion flowing through your torch.

[Greymatter Glass]

Sure, you can use stainless steel, costs about 4x as much.

... Sadly there's not a cheaper options that legal AND safe.

I had a plumber run about 120' of 1" clean/capped copper and 120' of 1" black iron pipe (for gas) around my shop with a total of 6 terminations per line (total of 12 tank valves), a high flow 2 stage oxygen reg rebuilt for liquid service, a high flow propane reg, the wall penetration for the gas, and 2 high pressure pig-tails to the regs... all inclusive (parts, material, labor) was about $2200 + a kick down of a nice piece ($100 retail maybe) and some little marbles.

I pretty much had to do it to be safe and legal in my shop, but even if I didn't the cost has turned out to be sooooo worth it. You get 150psi oxy and 25psi gas in a 1" pipe behind every torch and no one will see their flame flutter or pulse when someone else is working.

[Greymatter Glass]

so yes i did do a search for this but didnt come up with to much Im wanting to know if there is any thing other than copper pipe that can be used to hard line in for liquid o2 its the cost thats keeping me away from that thanks Jeff


how much pipe? what sized shop? how many terminations? I can give you an idea of what my guy would charge based on my bill. A smaller shop with 2 or 3 people would be under $1000 for sure. Well worth it. Hell, even a single person shop could benefit in some small way from hard lines.... not sure it would be worth it tho, unless your tanks are like 100' or more away from your torch.

Also, the copper doesn't care if you use liquid or compressed gas tanks, all that matters is the regulator. Most you're ever gonna run in the hard lines is maybe 200psi.

[glassblowingBiker]

sweet this would be for a 12 station shop..... The city is hard and yes we want it done right the first time So thanks for all the Info

[Greymatter Glass]

That's a big enough shop to make it worth doing for sure. You have to figure your costs into the rent - not just the fixed overhead. I amortized the building of the shop across 3 years it worked out to about $30/mo extra per station ($5000 build, 6 stations, 36 months, $29 and change per month per station)

[glassblowingBiker]

thats kinda what i was going to have to do some thing along that line again thanks for all the Help on this

[Adam Sultan]

Thanks, this post helps alot. now i hope all my calculations are right and i get pressure! I'm gonna be running 3 torches with 30-40 feet of 3/4 inch copper. with a hi flow regulator at the tank side set at like 100psi going to 3 regulators for each torch set at... 20-25 psi, i guess. hopefully that should work. (cant wait to just worry about blowing glass again)

[Riley]

welcome the melting pot adam, i really dig your discflips and have for a while.

good luck on getting back up and running.

[Greymatter Glass]

Yeah, ditto what Riley said, those flips are the shit. The setup you outlined sounds great, you're going to love the hardline set up.

Also, since my last post in this thread, Ive seen a shop set up with 1/2" rubber lines, run in PVC conduits on the wall (off the floor) with break-outs going to each bench.... it's not an ideal set up, but it seems to work. No station regs, but the 1/2" bore hose keeps 3 torches running with minimal flux when one turns on or off.

Not sure if it's legal either, I kinda doubt it is, but it works... and it's better and safer than having a rats nest of 1/4" hoses run around the floor.

[Master Yoda]

I heard someone up here say that the t grade hose has to be replaced yearly according to osha

[Mr. Wonka]

We use 3/8" hose as a manifold, and cut some brass Tees into them wherever we needed a work station. During AGI there's at least a dozen people working off of this system in the Looie building.

It's probably not up to code, but we don't have to worry about that here.

Tom

[schmoinkel]

here is a good thread too (http://www.talkglass.com/forum/showthread.php?t=10375&highlight=hard+line+oxy&page=3)

thanks for the info folks

[Waffles]

thanks tom!

[broken glass]

the way i understood the 2007 Ca fire code(now they use 2011) is that hardlining is only needed if you are hooking up to a machine, say like a gas fired kiln, but for torches I believe that regular gas lines should be good......at least that is what i hope......Also is hardlining one and done? I thought I heard that the seals need to be redone every few years or so?

[Adam Sultan]

I have a question, if a system only holds less than 100 psi, can i get away with using flange fittings instead of brazing the lines? for 30 feet running to 3 benches, can i get away with 1/2 L the whole way, or do i really need to get 3/4 or 5/8?

I think now the idea is to have a regulator tankside set at 60 or so psi, on the other end of the copper line a manifold splitting to 3 oxy regulators, then regular ole hose under the table running from the manifolds to the torches.

turns out that since I'm in a commercial district, i can only run 5 psi of gas. luckily thats exactly what the torches we'll be using require, and apparently, 3 torches running at 5psi doesnt mean 15psi, it means i only need 5psi in the lines. (it would be nice to be able to crank it up to 6 or 7 tho hmmm)

[Greymatter Glass]

I have a question, if a system only holds less than 100 psi, can i get away with using flange fittings instead of brazing the lines? for 30 feet running to 3 benches, can i get away with 1/2 L the whole way, or do i really need to get 3/4 or 5/8?


I assume you means flared?

Flanges made of copper/brass/stainless that are compatible with oxygen for high pressure use are much more expensive than just welding the pipe together. You have to braze the flanges on, then bolt them together.... kind of defeats the purpose.

So I assume you mean flared, which is what you use, but instead of simply soldering them together with a tin/lead alloy you must silver or bronze braze them. The tin/lead in solder will quickly oxidize and you'll have leaks everywhere.

For 3 stations 3/4" is plenty. In fact 5/8 would probably be fine... I wouldn't mess with 1/2" at relatively low pressure. I could look up the charts and do the math when I have more time but it's not just about pressure.



I think now the idea is to have a regulator tankside set at 60 or so psi, on the other end of the copper line a manifold splitting to 3 oxy regulators, then regular ole hose under the table running from the manifolds to the torches.


Figure out what the MAXIMUM pressure you'll need at the torch is and supply about 2x than to the manifold (from the tank reg). You need a higher back pressure on the lines to provide stable flow up to your maximum pressure.



turns out that since I'm in a commercial district, i can only run 5 psi of gas. luckily thats exactly what the torches we'll be using require, and apparently, 3 torches running at 5psi doesnt mean 15psi, it means i only need 5psi in the lines. (it would be nice to be able to crank it up to 6 or 7 tho hmmm)

If you're running a natural gas system you can get gas boosters that up the PSI. If you're running LP you can set it to a low pressure then up it a bit after inspection... still, anything past about 7-8 psi propane shouldn't be needed... remember, it's about flow, not pressure. Although the two are linked, flow is the more important number. So look at your numbers... you're missing one.

1 torch runs at 5 psi and "x" flow rate.
3 torches run at 5 psi and 3x flow rate.

As long as you can supply the flow rate required by the torch for the flame you want then pressure doesn't matter. The flow is regulated and ultimately limited by, the orifice in the valves.

-Doug


tl;dr: braze the lines, period. pressures are fine, but make sure they're gonna be high enough on oxygen.

[Greymatter Glass]

oh, also, you can use 1/2" lines for 3 torches with a higher back pressure... say 120 psi.... should work fine.

[broken glass]

gas booster for natural gas needs to be approved by city. Depending on where you are that can be a problem

[oldschooltofu]

i had my plumber use compression fittings, good to 80 psi
and it is up to code and works great, cost half the price of brazing

[Adam Sultan]

compression fittings, that must have been what the plumber was talking about. thanks everyone for all the clarity.

thanks for the tip about 1/2 line at a higher back pressure should run the 3 torches, that should save me some money too i think! thanks, this thread and you guys have been extremely helpful!..... wait.... i just realized i probably cant do both...

however if i skip the 3 regulators at the end of the manifold and just run like 60-80 psi in the compression fitting system like tofu was talking about, should solve my back pressure problem right? the manifold goes right into the hoses which run under the table. then the only way to adjust oxygen levels per torch is with the valves on the torch... could i do that?

[Adam Sultan]

I re-read tofu's set up on the other thread. so you have 1 regulator tankside set at 60-70 psi. and 1 regulator inside set at 40psi? is that how youre getting the backpressure that doug was talking about? What kind of manifold do you have inbetween the shop regulator and the torches? or did i mis-read and you have a regulator for each torch with a manifold in the main 80psi line?

[menty666]

So I assume you mean flared, which is what you use, but instead of simply soldering them together with a tin/lead alloy you must silver or bronze braze them. The tin/lead in solder will quickly oxidize and you'll have leaks everywhere.


Not to discount the rest of the message, but thanks. I would have never even considered that.

Funny how between oxidation and price, the oxygen tends to be the most troublesome thing we work with.

[Adam Sultan]

Ok after much talking with the plumber and building inspector about what was said here, It turns out that yes greymatter is correct, silver soldering (as my plumber in this area calls silver brazing) the pipe is the correct way to go, since flared fittings would be just as much work as welding, and compressional fittings wont pass code out here for oxygen, and neither the building inspector nor the plumber knew about the oxidizing problem in the tin or lead based solders. And since I'm already paying for the most expensive option, might as well go with that 3/4 inch main line just to make sure ive got my volume with my compression since it'll only add about 50$ to the overall cost.

thanks again for all the advice here! saved me some future headaches!!

[Adam Sultan]

unless, silver braze is actually something different than silver solder...


arg, how is it i've worked with a torch for 12 years but know virtually nothing about welding?!

[Greymatter Glass]

the silver alloys they use on copper pipe is actually brazing, but it's sometimes called silver solder. It's all about molecular diffusion.

Brazing is joining 2 dissimilar metals that wouldn't fuse (weld) together on their own via a third filler metal that will bond to both the other metals. It's a strong molecular bond that's done at much higher temperatures than soldering.

Soldering is using a low melting point (relative to the metals being joined) alloy to mechanically join 2 metals to each other, sort of like glue, but stronger and heat resistant. It's fine for low pressure stuff like water pipes, but the molecular bond is tenuous at higher pressures and can quickly leak and pull apart.

Welding is where you use actually fuse the metals together. You can weld copper but it takes a special torch (TIG welder) and a lot of skill to keep the whole pipe from melting in the blink of an eye.

[Greymatter Glass]

here this explains it better than I can:

http://www.copper.org/applications/plumbing/techcorner/soldering_brazing_explained.html

[n3rd]

doug rocks

[Firekist]

ditto, n3rd

[boxfan willy]

What are the reasons for not using BSP for O2 if you thoroughly cleaned the lines? We have always used copper, but used a short run of BSP for 02, after thoroughly scrubbing the line with acetone.

We are expanding our shop and redoing our lines, so this thread is great timing...

[Greymatter Glass]

Not really sure... I guess if you have brass or stainless threaded pipe and fittings you'd just have to check the pressure ratings and you should be ok...

I know that threaded brass pipe (usually NPT in the US) is like 10x more than flared copper of the same diameter (probably handles much higher pressure as well) SS probably the same. IIRC I think we used brass pipe for a manifold down at broadway a while back, an a 12' section was over $100 for the pipe, like 8 years ago.

If you're talking Black Iron pipe, like you can use for gas the reason is that it rusts... so 1. it will start to leak, and 2, it will start to collect in the lines and eventually in your torch. Might work fine short term for weeks, maybe even months, but over years it will deff start to leak and degrade.

[Adam Sultan]

I just wanted to finish up my hard line story in detail because perhaps it could help someone.

After going back and forth with the regular plumber who was going to use a tin based soder (even though it was called "sterling silver solder") i talked to some other brazing experts that pointed me to a local refrigeration company, tho their name is Donald's Electric. I called them a while back and asked the receptionist if they could install a copper line to run compressed oxygen gas, and the receptionist told me they don't do that. a couple weeks later i called again and asked specifically if they do silver braze on copper pipe, and she let me talk to a technician.

I told the technician exactly what i needed run, how much, and what it was for, and if he did silver braze, he told me that he's got guys that do silver braze all day long and that he'd come out and take a look at what i needed done because it sounded like i knew what i was talking about (thanks to Doug).

They ran 30ish feet of 7/8 inch copper pipe (they for some reason use the outside diameter of the pipe rather than the inside diameter, 7/8 in outside = 3/4 inch inside) with a few L's to get it to snake where it needed to go, this was all silver brazed.

It was my job to figure out what kinds of end couplings would be on either end of the line, and i went to my oxygen supplier and asked what i'd need. i went to lowes and got a 1/4 inch (inside diameter) brass nipple (a small section of 1/4 inch brass pipe which is male threaded on both ends.) two brass 1/4 inch female threaded couplings, and two 1/4 inch brass plugs. the plugs are just to seal the edges of the line while we're testing pressure. and i also got 2 3/4 inch brass solder on cut off valves. On both ends of the copper pipe, the brass cut off valves were welded (they use a slightly different grade silver braze to weld copper to brass) then a 3/4-1/2 reducer is welded on the other ends of the cut off valves, then, we cut the brass nipple in half and each half was then welded onto the reducers at both ends opf the system. (they used a pair of pliers to crimp the 1/2 inch reducer onto the nipple to hold it in there so it wouldnt flop around while they welded the 2 peices together..

the system goes like this:
Oxy tank>high flow regulator>short piece of high pressure hose>1/4 inch brass female couping> male nipple half (thats all screwed together, the welds start here)>1/2-3/4 inch copper reducer>cut off valve>3/4 inch pipe with a few 90 degree L's to get it through the outside wall, up over the ceiling tiles, and down to my glassblowing table>other cut off valve>reducer>threaded nipple>(end welds, the rest is screwed on) step down regulator(directly screwed onto the male nipple at the intake hole on the side of the regulator)>flash arrester>3 way splitter/manifold>hoses>torches.

They also drilled a hole in the side of the pipe near the tank side and welded on a little thingy that allows them to hook up a pressure gauge. well we screwed on the plugs onto the ends and put 100lbs of pressure on it. it held instantly you say? no, it didnt. it leaked at the cut off valves! (yes, it turns out that the heat of the braze was so hot, it melted the seal inside the cut off valve, even though they were specifically designed to be welded on) i was in shock, thinking they'd have to literally cut the cut off valves OFF of the pipe and figure something else out!

but i was wrong again, all they had to do was unscrew the cut off valve and put some Teflon tape in there and voila, held pressure.

the emergency cut off valves are just to make the building inspector happy. i could have probably just got away with one at the desk side, and now im realizing the one near the tank is a bit redundant lol! but I'm positive my building inspector will love them both. you may also be thinking "whats with the 1/4 inch stuff? can u bottleneck 3/4inch at both ends like that, doesnt it defeat the purpose?" both of my regulators are that size, so no matter what, the stuff passes through a bit of 1/4 line as soon as it goes through the regulators.

on a side note i was amazed at how similar the brazing process was to lampworking 4 mil rod. I offered the technicians a free joy ride behind my torch once my place was open and told them they'd make excellent glassblowers based on the skills i saw.

heres the staggering thing, the guy quoted me an estimate of 300$ labor and materials (not including the stuff i got from lowes which came to about 40$) Still i think its kinda low and ill believe that figure when the bill arrives. but in reality, these guys were quick. they were out of there before lunch and on to their next job!! they told me they run thousands of feet of sliver brazed copper pipe and that this job was a breeze. I have yet to test the system, if there are any more problems, I'll be sure to post here, hopefully I'll not be!

Again, I want to thank this forum for being here to answer my questions and specifically Doug. *lights ceremonial incense to pay tribute to Doug*

[cc_bob]

it turns out that the heat of the braze was so hot, it melted the seal inside the cut off valve, even though they were specifically designed to be welded on) i was in shock, thinking they'd have to literally cut the cut off valves OFF of the pipe and figure something else out!

but i was wrong again, all they had to do was unscrew the cut off valve and put some Teflon tape in there and voila, held pressure.

Sounds awesome but they should of disassembled the valve before soldering it:D

[Greymatter Glass]

thinking the same thing... usually those valves have a removable core, where anything that can't get hot is removed...

Anyways tho, sounds like you got a great deal on everything... $300 labor is a steal. Seriously.

Enjoy the set up, you'll never be able to work in a shop with long 1/4" hose runs again now tho :P