[dustyrustee]

Originally Posted by Workingwoods

Thing is, without the check valves, the air would not be forced to follow the up and down parts of the loops. As Oldred mentioned earlier, it would seek the path of least resistance, so it'd go straight to the horizontal drain line, and then to the outlet, instead of taking the long and winding road to the outlet.

Dustyrustee, I used galvanized pipe for everything except four elbows. I figure I'll take my chances on those, but keep an eye on things. There is a lot of anecdotal evidence out there from experienced pros that black pipe works just fine. I've also seen warnings about using it, but never any evidence of any actual problems.

Got the flex hoses replaced today. I found a local shop that specializes in hydraulic and air hoses and told the guy what I needed them for. He set me up with some 3/4" ID braided rubber hose (rated at 300psi), with industrial crimped 3/4" MIP male fittings on each end. (One end on each hose has a swivel fitting to make installation easier, too.) I feel much safer with these than I did with the other, clamped-on hoses. Now I'm chasing some small leaks on either side of the little Harbor Freight mini filter/regulators I put on my air station. I'll futz with them a bit more, and if I can't get then to seal correctly, I'll take them back, get a refund, and buy something a bit more robust.

Galvanized pipe.....no issue....the're hot dipped zinc in and out and have been used for water and steam lines forever......as for black elbows, a quick shot of spray primer and no fear after....

as the leaks go....if they are on threaded connections teflon based paste type pipe sealants excellent.....loctite blue thread adhesive excellent too...

[Workingwoods]

Originally Posted by dustyrustee

...as the leaks go....if they are on threaded connections teflon based paste type pipe sealants excellent.....loctite blue thread adhesive excellent too...

Thanks for the good suggestion. So far I've been using teflon tape on these regulators, but I've got some of the teflon paste, so I'll try that next. I think I'll also see if I can clean up the threads in the regulator bodies a bit...it looks like a little bit of the powder coating got into the first couple threads.

One of the guys on my pool league team is a plumbing contractor who specializes in high-end hospital and industrial piping. He told me they use both teflon paste and tape - together - on their threaded joints. I'd never heard of this approach, but I used it on all my 3/4" and 1/2" pipe and had no leaks to track down in those joints. Dunno why I decided to use only the tape on the <1/2" joints.

[robs ss]

At the bottom of the first page of where I describe the drawing, I listed the numbers for some high pressure hose if it will help. http://www.1969supersport.com/draw1.html

Rob

http://www.1969supersport.com

[dustyrustee]

Originally Posted by Workingwoods

Thanks for the good suggestion. So far I've been using teflon tape on these regulators, but I've got some of the teflon paste, so I'll try that next. I think I'll also see if I can clean up the threads in the regulator bodies a bit...it looks like a little bit of the powder coating got into the first couple threads.

One of the guys on my pool league team is a plumbing contractor who specializes in high-end hospital and industrial piping. He told me they use both teflon paste and tape - together - on their threaded joints. I'd never heard of this approach, but I used it on all my 3/4" and 1/2" pipe and had no leaks to track down in those joints. Dunno why I decided to use only the tape on the <1/2" joints.

Woods.....taper pipe threads are known as 'self-sealing threads'.....however that is only the case in a perfect world where the threads themselves would have no surface imperfections or rough areas to interfer w/their fitting...

Sooooo: that is where pipe dope comes in....it lubricates allowing for greater tightening thru reduced friction and fills surface imperfections on the threads...hence assuring a good seal result.

FYI: teflon tape has been obsolete for around 30 years now....I really dont even know why it is still sold....the bottom line is that the stuff is crap! and inefectual!

when you tighten up the joint, the tape does not remain on the threads but gets squeezed outwards.....so basically does nothing......IF you experiment and tape a thread, tighten together and then undo and look, you will see exactly what I have explained.....

As for what your pipefitter bud has told you ???????? I have never heard about such a proceedure....

I live and work in Edmonton, alberta, canada.....we are home to the largest accumulation of oil refineries and petro-chem plants in the whole world....
unimaginable amounts of piping work is done....teflon tape was banned here on industrial projects back in the late 1970's.....and I dont know of anyone around here working with piping for whatever purpose that uses the stuff for any purpose....

Myself, I have been involved in industrial mechanical work for 40 years now and have worked on all kinds of low and very high pressure plant piping....air, steam, water, hydraulics, etc...

So I definitely know what works and what doesn't and why....no guessing..no bull****...

If you want a reliable, leak free piping connection use:

1) master metallic lead pipe paste

2) "loctite PSP" teflon containing paste or equivalent like the permatex stuff

3) loctite blue or any other make of medium strength anaerobic thread locking and sealing liquid

4) permatex #2 non-hardening gasket paste" in a tube" or permatex aviation gasket sealant

for high pressure hydraulics loctite PSP is absolutely reliable..as well as many other loctite pipe thread sealing products.

if the threads are rough surface or torn....then the thread adhesives like loctite blue work best....in the case of a lot of the chineese parts, their threads are often rough and not too good...

If you take my advice you will have no problems....and no leaks and no re-does..guaranteed!!!

I really do know my stuff. I have been around a while...lots of varied exposure

just trying to help.....Ian

[Workingwoods]

Thanks, robs ss. It doesn't look like the hoses I got are quite as beefy as yours. Mine say "Thermold Valuflex 3/4" ID 300 PSI W.P.", and it looks like red rubber airline, except bigger. I needed two five footers, and they ended up costing a bit over $50 for the pair. (I'm sort of afraid to total up all my plumbing and electrical parts receipts. I know I spent way more than I had figured it'd cost, but I also figure things like safe hoses are money well spent. Nice air line drawings, BTW. Looks like you put a lot of work into those.

And dustyrustee...the teflon pipe dope/tape combo did the trick. No more leaks. Thanks again for kick-starting my brain.

[Edit to add...] Looks like we were posting at the same time. I'll definitely take your suggestions to heart if I end up re-doing any of my stuff. Like I said, so far it seems to be working out with the tape and dope. I'm definitely a woodbutcher in unfamiliar territory.

[dustyrustee]

Hi Woods....for future reference (re:hoses) to save you $$$$$$$$

regular air hose......barbed fittings......put permatex aviation gasket sealant
on hose barb and brush into ID of hose as well....assemble together AND use what are known as 'two-ear' style hose clamps....they are a round steel continuous band with two protruding areas that are squeezed together with a pair of pincer pliers.....these kind of clamps duplicate the action of the crimped on ferrules that the hose shop put on....and are not costly...for added insurance you can double up on the clamps, but not at all necessary..

one brand name for these clamps is Orlicker.....the aviation sealant becomes a very secure adhesive once it cures....and glues the hose to the fitting...

I make it a point to use aviation gasket sealant on all hoses...radiator, heater etc.

It bonds super good...but to remove the hose you gotta warm up well with an electric heat gun to soften and loosen the bond....otherwise you gotta cut the hose open with a razor knife to remove....

[txturbo]

All I did was run a 20 foot piece of 3/4" galvanized pipe along the wall with a 1/4"/ft slope.I put a turn down on the end opposite the compressor with a drain valve and my quick connects come off the top of the main run. No problems with water.It was a lot cheaper and easier to assemble than the copper tubing route.

[oldred]

I agree with the advice to avoid using Teflon tape, it's useless. While the other suggestions for sealing threads will work also I would strongly recommend avoiding Teflon of ANY kind on an air line that is to be used for painting! With paint being as expensive as it is the Teflon could be a very costly mistake since even microscopic particles can cause MAJOR problems with paint! (read fisheye ) In fact Teflon and silicone in any form should never be used on any paint equipment or around any surface that is to to be painted. I have used Permatex sealant for years on airline piping and it has always worked well for me.

[robs ss]

You can use teflon tape or paste or whatever you want to on black pipe, it has no effect on contaminating the air that comes out the end.

I run 170 feet of 3/4'' black pipe in all different angles and directions with only two unions.

I have zero leakage, any cheap pipe dope will work, but you need to clean the connections with lacquer thinner and a small wire brush.

Get a spray bottle for the lacquer thinner, I use a spray can, something you can rinse the connections off good.

I probably have at least three different tubes of pipe dope laying around and half rolls of tape, I use whatever I can find the quickest.

You hear about rust in black pipe that will give you problems, thats just another myth, if you filter your airlines, you will never even know if there rusty or not, it just doesn't matter.

Some of my lines have been up for twenty years, and the last f-88 filter I have in line, the stone in it is snow white.

If you run black pipe and taper it downhill, put drains and 3 or 4 Sharpe f-88 filters in, you will never need an air dryer, I run three different blasters, 1100 lbs of sand on the last body, zero moisture, without an air dryer.

You run your air lines so they work, not for looks.

Air dryers, dessicants and what have you need maintenance, and are not needed if you run enough black pipe, you run enough to cool the air down, then drain or filter it.

Air compressors make water, you can't get around that, but you can keep it out of that sandblaster pot or spray gun.

Rob

http://www.1969supersport.com

[oldred]

Originally Posted by robs ss

You hear about rust in black pipe that will give you problems, thats just another myth, if you filter your airlines, you will never even know if there rusty or not, it just doesn't matter.

Some of my lines have been up for twenty years, and the last f-88 filter I have in line, the stone in it is snow white.http://www.1969supersport.com

I have removed some very old black pipe systems that were in excellent shape inside and I have always maintained that the rust problem with it is not really a problem at all and I would not hesitate to use black iron pipe. Sure there was some rust mostly around fittings and the bottoms of drains but nothing that should cause a problem since the air must be filtered anyway, I am talking about minor rusting here and not heavy scale which I have never seen form in an operating airline system. BTW I have also seen rust in some galvanized pipe too.


That Sharpe 88/880 filter/separator setup is without a doubt the best money spent on any air system.

[capta1n]

Hey guys, I have been thinking about this type of a system for my shop. I like the idea of the drain manifold and was thinking how to simplify the system. Instead of using check valves and a ball valve at the end of the manifold, I am planning to leave the end of the manifold open and use a ball type valve between the down tube connections(as 11Echo mentioned). Any thoughts on this idea?
Regards.
j.L>

[11echo]

capta1n ...Actually I think this is a good idea! I understand what oldred was saying about the air taking the path of lease resistants, but because these are "spring loaded" check vlv.s there would have to be a large quantity of water there to be able the actuate the spring in the check vlv. The "danger" here is that there could have such a large quantity of water that the operating air could pick up a slug of water and push it through the system.
IF you had an open system the water (as it formed) would naturally seek the lowest point. So all you need is a "dead leg" (collecting point - pipe in the vertical to act as a well) with a valve on the bottom to drain the liquid off. I personally like ball valves ...quick acting quarter turn off and on. But globe valve would be my second choice ...good seat to get it shut down with no leaks. Again my $0.02 ...Mark

[Workingwoods]

Echo, I still don't think you're understanding how the check valves play into the equation. They sit there closed, doing nothing until I open the drain valve at the end of the line. Until then, the water sits on top of them, at the bottom of the drop tubes (but above the horizontal collection tube). When I open drain the valve, the water then passes through the check valve with the air that's blown through.

Without the check valves, during normal use the air would go straight to the horizontal collection tube, then back up the last leg of the drying loop, completely bypassing the up and down loops. The air would travel a much shorter distance, and thus not be cooled as well, if I didn't have the check valves.

The water is not actuating the check valves, so it has nothing to do with the amount of water collected. The opening of the valve downstream at the end of the horizontal collection pipe is what makes the check valves open. Any water on top of the check valve is then blown through the valve. When the drain valve is closed, the check valves are closed, and the water accumulates above them again.

Captain, you definitely could replace the check valves with individual ball valves, and still have them feed into the horizontal pipe to send the water away. (And you wouldn't need the valve at the end of the horizontal pipe like I have.) You could then open and close each valve, one at a time, and drain any water that had collected in the respective drop tubes. The reason I used the check valves is because I can't easily get to the bottom of the drying rack to open each valve.

In real-world use so far, I'd say about 90% of my water is coming out of the compressor tank drain itself. The other 10% or so is coming out of the drying rack. All the other drainage drops have been bone dry so far. I'd say it works.

I hope this helps clarify things a bit.

[capta1n]

I am close to finishing my unit. I am excited to get it in place, as it gets very humid here in Michigan. I am leaving myself some space to change the down tubes to a manifold if I need to do so in the future. With that in mind, I would like to know more about the check valves mentioned in the thread. If you could tell me where I could find them and a price I would appreciate your help. I am looking for information on both the spring type and the swing type.

Best regards.
j.L>

[Workingwoods]

I found the check valves on eBay. I don't know if those kind of links are allowed here, but if you search for "spring check valve" you'll see the ones I got. The seller is in Puerto Rico, but he ships USPS priority, so it didn't take any longer than if the guy had been on the East Coast.

As I understand things (but I could be wrong), the swing check valves only work in a horizontal position, so they wouldn't be a good match for this application.