air line installation

[jlaird]

This is my first post. What a great forum!

I'm going to run 3/4" black iron pipe in my two car garage. As I'm thinking about the install, two questions come to mind. First one is how tight do you thread the fittings? I'll probably use some type of paste with teflon. Just wondering how much you tighten them.

Second questions is what happens if you get a leak in the middle of the system? Would you have to take it all apart up to the point of the leak?

Thanks for any install tips you can provide.

josh

 

[plastics]

used threaded iron pipe in my last shop. I put a temporary plug or cap after each threaded joint and then leak tested each joint before moving downstream to the next joint, a little extra work, but I did not have to take anything apart later to repair a leak. Use a thread sealer and get it tight eonoug so that it does not leak.

I put copper in the new shop. Having used both, I think copper is probably a little less work to install.

 

[RAYJAY]

this is the way I installed my air lines. never get any water at all and i used a couple of unions in my install to help if i had any leaks or want to change it later had copper in my last place and i like the black pipe better,stays cooler longer, so it cools the air better than copper, a lot of guys on here say you want to transfer heat with the pipe in all you want to cool the air not transfer it to the piping

Jeff

http://www.tptools.com/StaticText/airline-piping-diagram.pdf

 

[jlaird]

I put a temporary plug or cap after each threaded joint and then leak tested each joint before moving downstream to the next joint, a little extra work, but I did not have to take anything apart later to repair a leak.

Sounds like a good idea. I was thinking of the same thing. One question though on thread sealants, you can immediately put air pressure to them right? You don't need to let them dry at all?

 

[jlaird]

I've seen that diagram before many times and your reply just made me think of another question, what is the difference between a coupling and a union?

 

[slider]

Bah.
Just installed my Black iron pipe today. Only about 10 joints but one is leaking on test. Yep nothing else to do other than take the whole lot apart again......
Need something more reliable than PTFE tape - or just alot more of it.

 

[83diesel]

I've always used the teflon pipe dope. The tape takes twice as long and the sealant seems to conform to the defects in the threads and pipes. The only trouble I've had with leaks is faulty ball valves or quick connect couplers.

Putting unions in the system is an excellent idea. Not just for repairs but as many have said that you never know when you will say later, hey it would be handy to have a coupler here.

Good luck.

 

[jlaird]

answered my own question about union vs. coupling. Here it is for others info:

a coupling allows you to join two pieces of pipe, either with threads or by gluing, soldering or welding. A union, on the other hand, does that too, but it allows you to separate the two sections with a threaded joint in the middle, so that all the movement is at the union, not on the individual sections of pipe.

 

[porcupine73]

I used BIP for my two, two bay garage setup. It took me a long time to connect. If you use BIP, my suggestions are:
1. do not thread any pipe yourself. At least not with the harbor freight threading kit. The main leaks I had were the pipe pieces I threaded myself.

2. Use a GOOD hardening if possible thread dope. I used this stuff from home despot rectorseal teflon paste, covered with teflon tape, covered with paste. I still have some slight leaks I have not found.

3. If you use any pipe plugs, do NOT overtighten these as they seem very suscdptilbe to leaking of overtightened.

4. For intermediate, hard to fix leaks, I have cleaned the area, sanded slightly, cleaned again (with chorlinated brake cleaner), then applied generously epoxy liquid metal, ie PC-6 or jb weld. This seems to work very well.

5. For your original question: how tight. Tapered pipe fittings are typically spec'd for a given TPFT (turns past finger tight) rather than a specific torque.

6. If I run compressed air pipe again, it will be thick wall copper with a good torch and refrigeration grade solder. Another time consuming part on BIP is that on long runs you need to secure the pipe with pipe clamps or something before you can really torque down the fittings.

 

[rickairmedic]

Heres a nice chart from rectorseal that might help any time I work with BIP I tighten till I cant tighten anymore . I do know when I do my air lines I will be using copper granted I get refrigeration pipe wholesale .

http://www.rectorseal.com/chrt.htm


Rick

 

[Industrial Concepts]

Heres a nice chart from rectorseal that might help any time I work with BIP I tighten till I cant tighten anymore . I do know when I do my air lines I will be using copper granted I get refrigeration pipe wholesale .

http://www.rectorseal.com/chrt.htm


Rick

Rick,
Where do buy Rectorseal in Louisville? I've been using a Permatex thread sealant for Pneumatic/Hydrallic (forget the number). It works great, I can apply pressure imediately. Too pricey to do a big piping job with. I manly use it on couplers, tools & equipment tie in.
Bob

 

[rickairmedic]

Hi Bob Home depot carries rectorseal you can also get it at grainger I am pretty sure and most of the plumbing supply houses what part of town are you in I can probably point you to the neaerest plumbing supply house . They unlike HVAC supply houses will sell to the public although regular folks off the street will probably pay reyail insttead of wholesale.


Rick

 

[Industrial Concepts]

Rick,
I am all over town. I typically buy from SWH or Masters Supply. Some pipe fitters in IL told me about the Tru-Blue. The wrap their pipe a few passes with tape & the Tru-Blue. But, I have'nt seen the product in Louisville. To answer your question I'm in Southwest side of town.
Bob

 

[rickairmedic]

LOL OK Bob so you live out here with me I'm in PRP I will check with a few of my suppliers tomorrow and see if any of them carry tru-blue since we are in the same part of town I could probably pick it up for you wholesale . I am all over town myself doing Heating and Air . We opened our own company this year so if you have freinds who need HVAC work send em to the Airmedic we're in all the yeller books at least till we decide which ones bring us the most work.

Rick

 

[RAYJAY]

I've seen that diagram before many times and your reply just made me think of another question, what is the difference between a coupling and a union?

COUPLING

UNION

the union can be taken apart, the coupling can not, i all way use unions when ever i think i may need to remove a pipe section

 

[larry4406]

Rectorseal - good stuff. I used it on my air and propane lines in my shop with black iron pipe. Threaded everything myself from 1 inch to 1/2 inch. Apply rectorseal generously to the male and female ends and tighten. No leaks for me and I did not apply additional teflon tape. You can get it at Home Depot or Lowes. It looks kinda like a brown mustard color.

 

[Industrial Concepts]

LOL OK Bob so you live out here with me I'm in PRP I will check with a few of my suppliers tomorrow and see if any of them carry tru-blue since we are in the same part of town I could probably pick it up for you wholesale . I am all over town myself doing Heating and Air . We opened our own company this year so if you have freinds who need HVAC work send em to the Airmedic we're in all the yeller books at least till we decide which ones bring us the most work.

Rick

Rick,
You should see the airline we put in Hyundia of Louisville on Dixie. We are just finishing up the airline for Bob Montgomery's new Collision Center. These are all aluminum with brass from the ball valves to the connection. At the spray booths we put in Tsunami water separator & oil coalescors. We've gotten away from the desicant dryers at the paint booths.
Bob

 

[pirate]

What are all of yiou using for a inline filter? Need something to filter out water. I only have a 33 gallon tank but even draining the tank on a regular basis I still get moisture at the exhaust of air tools. How much does a filter cost and what should I be looking for as far as features and brands. Thanks

 

[HoosierBuddy]

Most of my pipe experience is with natural gas...but I think it probably applies.

I'm not a big fan of teflon tape. It's neater than pipe dope for sure, but it's tricky to use correctly, requires more torque for a good seal, and is ultimately more prone to leaking than pipe dope. Of all the pipe dopes I've used, the best is (in my opinion) Leak Lock, which is a blue non-hardening liquid. Hardening pipe dopes (thread sealants) tend to develop leaks when they dry out. These leaks can show up 1 to 30 years after installation, and generally require complete disassembly, cleaning, and redoping to fix.

I've never left a leak when using Leak Lock. Not one. Ever.

On the union vs coupling question. Unions are a great if you are trying to fix a leak, as you can work from there. Just keep in mind that unions are also really bad about leaking. It's a compression fitting, and the center part goes together dry with no sealant. Sometimes they develop leaks on the sealing face. If they do, the best fix is to replace them. I've seen guys waste a lot of time screwing around with them to make them quit leaking. The only thing I've seen that was effective was trash canning them and getting installing a new one.

AND...real men thread their own pipe. Ridgid makes a good pipe threader. These are probably available for rent in your area.

Phil

 

[rburke65]

I have been looking at the TP tool diagram off and on for some time and if you look at the green and yellow drops on the diagram, the have the union placed before the shut off valve. This would not allow you to shut off the air/water supply and then disassemble the piping using the union. Anyone more knowledgable in the fine art of plumbing on why this is pictured as such, or is the diagram wrong?

 

[jlaird]

Most of my pipe experience is with natural gas...but I think it probably applies.

I'm not a big fan of teflon tape. It's neater than pipe dope for sure, but it's tricky to use correctly, requires more torque for a good seal, and is ultimately more prone to leaking than pipe dope. Of all the pipe dopes I've used, the best is (in my opinion) Leak Lock, which is a blue non-hardening liquid. Hardening pipe dopes (thread sealants) tend to develop leaks when they dry out. These leaks can show up 1 to 30 years after installation, and generally require complete disassembly, cleaning, and redoping to fix.

I've never left a leak when using Leak Lock. Not one. Ever.

On the union vs coupling question. Unions are a great if you are trying to fix a leak, as you can work from there. Just keep in mind that unions are also really bad about leaking. It's a compression fitting, and the center part goes together dry with no sealant. Sometimes they develop leaks on the sealing face. If they do, the best fix is to replace them. I've seen guys waste a lot of time screwing around with them to make them quit leaking. The only thing I've seen that was effective was trash canning them and getting installing a new one.

AND...real men thread their own pipe. Ridgid makes a good pipe threader. These are probably available for rent in your area.

Phil

Phil,

Do you tighten the fittings as tight as you can get them? If not, how many turns past hand tight?

Thanks for the info on the unions. Good thing to think about. Where is the Leak Lock available? Is that the brand name?

 

[busted knuckle]

Okay, now I need to be informed if I am being led down the wrong road. I went to the hardware store to get 1/2" pipe etc, for plumbing my compressor for air tools and a grit blast cabinet. The guy says why not use schedule 40 PVC that is rated @ 600 PSI. It costs less and you can cut and glue it yourself instead of them. I will only be using about 90 PSI for the air tools and cabinet. So whats the deal moisture, safety, longevity? I'm a new comer and sure could use some help. Just getting the garage cleaned and organized. Thanks.

 

[rickairmedic]

BK there are many many stories on the net aboutt PVC air lines tthe general feeling is that they are not a good idea if they fail for any reason you will have shrapnel flying . I personally would not suggest PVC for airlines as I have read more bad tthan good aboutt it do a search here or over at Shop Floor Talk and you will probably have hours of reading ahead . I have read of a few peaple who have had PVC for years and no problems **** I have also read stories of bursting lines and peaple running for cover . I can also ttell you the manufacturers dontt recomend it . I would say the hardware store guy should be drawn and quartered if for no other reason than he is asking for a lawsuit in todays sue happy environment when something does happen and he recomended it . I would say sttick to copper or black iron and you will be happy and safe .

Rick

 

[JOHNMAN]

Many years ago (25 or so), we plumbed a garage with PVC and it worked well. We went along fat, dumb, and happy. When we moved away from there, we took down the PVC. As we took it down (perhaps 4-5 years later) it was brittle enough that it could be easily broken up by hand. (SCARY)

We have used copper ever since.

In my opinion:

Black Iron would be nice, but running back and forth to the hardware store to have custom lengths threaded would cost about the same in gas money. If you can thread your own pipe (and do it correctly) you would be money ahead going black iron.

 

[busted knuckle]

Well based upon what I have found and looking at what was said @ shop floor talk I will bite the bullet and run thick walled copper pipe. I didn't like the thought of the quick disconnects that would be sticking out of being possibly being broken if hit. With the copper I can solder it all myself instead of having to get iron pipe threaded. I'll be using the thicked walled copper and not the typical household stuff. I thick it will have a much cleaner look and safer. Thanks all!!!!!

 

[Lyaec350]

You don't need to use the thick wall. According to the Copper handbook Type M copper in 3/4" at 400* F working pressure is something like 700 psi. The combined factor of safety between 175 lbs (1/4 the max working) and working pressure vs burst pressure gives an overall factor of safety at least 8, more than enough.

 

[MDH9252]

Can someone enlighten me on the difference between Refrigeration solder VS. normal plumbers solder? What type (or designation) solder should be used on airlines?

 

[porcupine73]

Some solder info from mcmaster
Tin/Silver— For use on food service equipment, refrigeration, plumbing, heating, and air conditioning. Meets J-STD-004, 005, 006.
Tin/Antimony— Featuring high strength and a matte finish, it melts and flows like a 50/50 tin/lead solder. For air-conditioning, refrigeration, and high-temperature applications.
Aqua-Pure— Meets federal regulations for the use of lead-free solders in drinking water systems. It melts and flows like a 50/50 tin/lead solder.
Tin/Copper— Its relatively low cost makes this an economical choice. Works well in electrical and electronics applications.
63/37 Tin/Lead— This tin/lead solder has exceptional tinning and wetting properties, as well as a low melting point. Use in stainless steel and electronic work.
60/40 Tin/Lead— The most popular dipping solder for electronic applications. Its low melting range makes it ideal for delicate work.
50/50 Tin/Lead— General purpose solder handles standard tinning and sheet metal work.
40/60 Tin/Lead— A good general purpose dipping solder.
30/70 Tin/Lead— Solder for machine and torch soldering.
100% Tin— Has good strength and is nondulling. Use it on food processing equipment, as well as for alloying and tinning wire. ROHS compliant.
High Melting Point— 97.5% lead, 1.5% silver, and 1% tin. Use for electric work and for initial solders since its high melting point prevents remelting when soldering successive joints.
Extra Strong— 54% lead, 45% tin, and 1% silver. Has exceptional strength. It is nondulling with a bright, long-lasting finish and is for use on stainless steel.

 

[rickairmedic]

I use stay brite #8 for most refrigeration work other than Puron where I use hard silver sticks . Stay brite #8 will work fine for airline work it has more silver than standard plumbing solder and a higher tensil strength most R-22 HVAC systems have pressures over 200PSI on the high side and I have never had a failure using stay brite #8 .


http://www.weldfabulous.com/Shop/Control/Product/fp/SFV/32435/vpid/4529857/vpcsid/0/rid/126707


Rick

 

[Alex]

I used BIP for my two, two bay garage setup. It took me a long time to connect. If you use BIP, my suggestions are:
1. do not thread any pipe yourself. At least not with the harbor freight threading kit. The main leaks I had were the pipe pieces I threaded myself.

2. Use a GOOD hardening if possible thread dope. I used this stuff from home despot rectorseal teflon paste, covered with teflon tape, covered with paste. I still have some slight leaks I have not found.

3. If you use any pipe plugs, do NOT overtighten these as they seem very suscdptilbe to leaking of overtightened.

4. For intermediate, hard to fix leaks, I have cleaned the area, sanded slightly, cleaned again (with chorlinated brake cleaner), then applied generously epoxy liquid metal, ie PC-6 or jb weld. This seems to work very well.

5. For your original question: how tight. Tapered pipe fittings are typically spec'd for a given TPFT (turns past finger tight) rather than a specific torque.

6. If I run compressed air pipe again, it will be thick wall copper with a good torch and refrigeration grade solder. Another time consuming part on BIP is that on long runs you need to secure the pipe with pipe clamps or something before you can really torque down the fittings.

I used the HF threader($19.99), worked just fine with teflon dope,just secure in a good vise with pipe jaws and tighten away .If I never use it again or if someone "borrowes" it and i don't get it back Oh well!!

have been looking at the TP tool diagram off and on for some time and if you look at the green and yellow drops on the diagram, the have the union placed before the shut off valve. This would not allow you to shut off the air/water supply and then disassemble the piping using the union. Anyone more knowledgable in the fine art of plumbing on why this is pictured as such, or is the diagram wrong?

I saw that too. so i just put the shut off before the union. worked out fine ,even better as I was able to put the lower section togethet on the work bench vise then just tighten the union.......

 

[HoosierBuddy]

Phil,

Do you tighten the fittings as tight as you can get them? If not, how many turns past hand tight?

Thanks for the info on the unions. Good thing to think about. Where is the Leak Lock available? Is that the brand name?

This is really a trick question.

How tight you can crank a pipe fitting is limited only by the size of your pipe wrench and the strength of the chain you have it connected to your backhoe bucket with

For standard household plumbing, I use 12 to 16 inch pipe wrenches. I don't tighten anything as tight as I can tighten it. It takes a bit of "feel". The biggest mistake most novices make is probably not using a second wrench to back up the first. Pipe wrenches are used 2 at a time with one working against the other. When you back yourself up with the second wrench, you gain leverage and "feel" on tightening your fitting.

Leak Lock is a trade name for a brand of pipe sealant made by Highside Chemical. http://www.highsidechem.com/leaklck.html For best results, they recommend doping BOTH male and female threads and then allowing a couple of minutes of drying time before assembling the threads. It's a little slower to apply because of this. They (Highside) tells me this technique became more critical when Chinese pipe fittings began showing up in the U.S. market, as the thread tolerances are not exactly up to snuff in some cases.

Around here, the local hardware stores and plumbing distributors sell it. If you check the url above, it has a phone number you can call to find your local distributor. They sell the same thing with teflon in it...but when I asked them "why?" all they could tell me was some plumbers won't buy a thread sealant if it doesn't say "teflon" on it. I was left with the impression they didn't really feel teflon is necessary...they just use it as a marketing tool.

BTW...can you tell I've spent a lot more time thinking about pipe dope than most people? When you're responsible for several hundred miles of pipelines with thousands of threaded fittings, it's worth spending a few hours of research.

Good Luck!

Phil