Fuel tanks and delivery lines

I do plan on rinsing them out with water, good suggestion on pressurizing the water first. I was just going to sink them in a 45 gallon drum filled with water and look for bubbles.

The warning tag on the compressor states do not fill beyond 125 psi. The automatic shut off was also set to 125 psi. Safety relief valve has 140 psi stamped on it.

As for filler rods, I’m not going out and buying anything special like E309.

This is what I have in stock, I planned on using the ER316/316L or the ER80S–B2. Your thoughts?
I personally thought that the ER70S-2 would be on the little soft side, And the DUR600 would be a little too hard.

 

309 would be my choice, but I'm no metallurgist. We have hydro shops that test our O2 bottles. It takes 3weeks and is stupid expensive for these guys to dunk a bottle and pressure test it.
Half the time, you get a leak just from screwing with it in the airplane. Fortunately, it's a 5yr test.

Zap the 4ft is the 150cf! I've got the one just below that at 125cf. Next time I'm going to see if I can trade up. There is very little size difference between the two and I'll happily take the extra gas.
Anything bigger at my lws requires a rental contract and they are a pain in the ass to move anyways... Screw that. I already get "the look" when I chuck my 125 in the trunk of the car.

 

Personally I would want soft weld metal. The compressor tanks are likely mild steel and the ER70S-2 would be appropriate. Once you get to where you can measure it put a micrometer on it and it's easy enough to calculate the maximum pressure per ASME Section VIII which would be a good start. The soft weld metal allows a little deformation in the area of the weld prior to failure. You'll have some shrinkage and extra stresses in the area of the weld after welding and if you have a hard spot it can either crack or fatigue in a few pressure cycles and develop a leak or rupture.

It is worth buying a pound of ER-309 when you need to weld unknown metals, and dissimilar metals to each other. It is quite universal and very forgiving.

The bubble test submerged is great for a 15 psi test. I would not handle it at 155 psi with air.

If the relief is the factory relief then one would expect 140 psi is the safe working limit and the vessel should be tested to 210 psi. However, it is reasonable to only test to 1-1/2 times the pressure you want to use it at. I agree with testing it at 155 psi and then assume it is good for 70 psi because I would use 2 times the operating pressure for a test pressure for a little extra safety.

Note: Any welding on a pressure vessel that operates over 15 psi in the U.S. is required by law to be done only by certified welders using properly tested welding procedures on metal you have mill certifications for. If you choose to not abide by the law you accept the liability risk of potential injury and loss of life. My suggestions are an attempt to improve your results should you choose to ignore the law, which I don't recommend. We have to recognize that others reading this forum may attempt welding on much larger pressure vessels and may not be as competent at welding as you are. It is serious business and can result in your death or the death of others.

 

I have a ton of respect and regard for Andy and HT1 who really know their way around this stuff (this is way out of my wheelhouse), but it seems like a pretty high standard for something that will probably never see 20psi. We just actually considered a plastic container and now we're talking 155psi. All were trying to do is keep the tank from making a mess. There may be legacy concerns with the tank but once OMM cuts a hole in it in his shed, high pressure use goes out the window, tested or not.
I transfer my new WMO oil to my tank from a 30 gallon sealed steel drum connected with 3/4" MHT (garden hose) fittings from the vent hole in the drum lid. I hoist the drum 10' slightly canted so it drains into the tank, but it's slow. If I'm only draining a gallon or two gravity feed is fine but if I have more than that I add 3psi to the drum through the bung which has a compressor fitting and a 5psi popoff. Otherwise it would take hours. The drum doesn't bloat. I've only added pressure in a couple of instances because I generally only get new oil a couple gallons at a time. It's definitely not a KISS setup, but I have the headspace in my barn and once I had set up the tank and hoist arrangement it's as easy as can be.

Pete

 

I'm with you Pete. OMM said he was trying to preserve the integrity of the vessels and that's when the issues begin. Legally, anything under 15 psi is not under Code jurisdiction. Also anything under 20% of material yield strength. Typically tanks like these will not be designed for over 72% of yield and likely 60%. But if you assume 72% and the tank is rated for 140 psi if you choose to use it only under 38 psi then it would be under 20% and also exempt from the legal requirements. You can have some pretty bad welding and not get into trouble at 20% of yield strength.

I only run my waste oil tank to 10 psi as it gives me plenty of flow for WVO, WMO, and old gear grease. Lately I've been running a lot of stale gasoline. Boy it burns sweetly.

 

Andy, The tank wall thickness is 0.085”.

I am going to high pressure test it once or twice and then it will never see more than 10 psi.

There will only be one inlet into each of the tanks that will have a 3/4 NPTF. And then these four pieces going to what I had on top of the Jerry cans.

 

Then that's your working pressure, 10psi. Test it to 25 and call it a day. That would be your personal test of 2.5 times.
Run it to 50 if you want to really feel comfy about your work. Don't you trust your regulator? Stick a second one on there if ya have to.

 

Quick estimate with 0.085" wt and 8" diameter the new tank would be good for over 300 psi.

If you can supply more than 10 psi to it you need a relief valve to dump pressure if it gets too high.

 

They are 7 inch diameter and 15 inches long. I’m going to test them with a male air fitting with ball valve. I do highly appreciate your suggestion on filling tank right up with water for the test.

Here’s a better idea of what it will look like finished (not including the copper pipe which will extend down to the bottom of tank). I will be soldering the tea into the brass cap.

 

ER70S is probably stronger then the Base metal and the Closest composition go with that ,
make sure there is an opening while you weld preferably away from you . there is a slight chance that the tank has a little oil in it from the compressor, that will heat up and burn and shoot a small flame out any opening ... it's a possibility, pretty unlikely,
if for some weird reason I cannot think of you cannot leave an opening while you weld you really need to go to plan B or inert the tank with argon.

whoever said put a relief valve on it likes you, there is always the possibility of you getting the full force of your compressor into the Tank so testing it to that, is a nice safety , but a relief valve say at 20PSI is a really prudent here is a link for a 25PSI https://www.amazon.com/Kingston-112...9BNQPYMKYW8&psc=1&refRID=SGWA1JAB69BNQPYMKYW8


V/r HT1

 

Hell for $18, I'd weld a bung on just to support that little 25psi thingamajigger. I didn't know they came that small. Good stuff.

 

Well I’ve been bunging today and I put in a request for the other scrap blue compressor. Thanks for the link HT1. I followed the link and I see they have a 30 psi for $13. I might pressure test it using the old pressure relief valves and then maybe swap them out in the future. They have a bit of a tall profile. I will have to see what I come up with for handles on the tanks first.

 

Nice work! BUNG is such a fun word!

 

Yep, but we need to be careful. It might and up in the restricted list....

 

A little late for a reply, but I use a stick welder for everything, with a $300.00 Lincoln AC tombstone.
I ran across some 1/8" Washington Alloy 6011 rods a few years ago, after experiencing a lot of problems with other brands, and having some weld failures.
The local supply house recommended them, and I have had great success with them.
https://weldingwire.com/products/Electrodes-Low-HydrogenLow-Alloy/E6011

I can use them at 40 amps to weld sheet metal, or over 100 amps to weld the thick stuff.

Its a great all-purpose, all-position rod with good penetration, and fast freeze.
The arc stability is very good, and I can use it to fill in oversized gaps and such when the fit is not too good, which is often when I am trying to quickly fabricate some foundry equipment.

I have considered buying a TIG, but I can't put that much cash into something that I would only use occasionally.

I use a nickel rod to weld stainless, and that works pretty good to.
I forget the brand of the nickel rods that I have.

I started stick welding when I was 5 because it kept me out of my dad's hair, since my mom forced him to take me to work with him on weekends.
I would sit there for hours welding away on "stuff", using a fantastic old AC/DC Lincoln, with DC rods.
A good DC rod with the correct polarity will basically weld itself, and I have considered getting an AC/DC Lincoln, but I really don't have problems with AC only, so no need wasting money fixing problems that I don't have.

I learned how to stick weld with AC when I was about 14, and it took me a day or so to get the hang of it.
AC takes a lot more fine control of the rod tip, especially with thin sheet metal.

An in-out movement actually works well at 40 amps on thin steel, and prevents melt-throughs.

.

 

Nowadays I take nickel Arc rod and hammer off the flux and use it for tig welding cast iron to anything. I do not have a tombstone anymore. Nowadays (outside work), I only have a ESAB DTA 200, 40 A fed.

 

I would like to upgrade my welder, but the little tombstone is such a workhorse.
I have been welding with it for 30 years, and never a problem, so I figure why fix something that works that well.

If I welded anything other than steel and stainless, I would definitely upgrade to a nice TIG machine.

Edit:
I actually went and looked at a nice TIG machine one time, and when I told my wife about it, she said "You better not spend $3,500.00 on a #%$^#%&$& welding machine", and so the case was closed.

.

 

I sold my old Lincoln tombstone for $200 Canadian and picked up this smallest transformer based, continuous service for $600 Canadian. It is a ARC/TIG Machine.


I’ve been really looking hard at purchasing the ESAB 205ic AC/DC but it’s a pretty stiff pill to swallow. It is inverter-based weighing maybe 50 pounds. (My transformer DTA weighs close to 600 pounds). If I could justify the ESAB 205ic AC/DC which run about $3000, I would be in dreamland. Don’t worry, my wife keeps kicking me awake Too!

 

That esab is a decent machine for the money. figure a little under 2k. It may carry the same name as your monster, but I can guarantee it's not the same quality. They are assembling them in South carolina last I heard, but john deer also builds their JUNK here. Again, with imported parts from far east.
If you are on a budget, the new chinese alphatig is hard to beat(like 800bucks!). The new model fixed a bunch of crap from the first one. There is some nice features on these newer ac/dc machines and the tech is moving so fast it almost makes sense to go cheap and plan on dumping it in 3-5 years.

I went a different route and chose a machine that had nothing to do with china or mexico (lincoln with chinese parts). Who knew the italians that cant build a decent car to save their lives know what they're doing when it comes to welding machines? Miller for production work IF you can get local service, but expect to sell a kidney. Welding junkie on YT has been to hell in back on a new miller. SO that kind of blows that theory. I just know every time I sit down at the table, I seem to forget about everything else at that moment and it feels good for once not to fight sub standard equipment. Just like a snap on ratchet is stupid money and does what a husky does, it just feels right in your hand and that is worth the price of admission.

 

I don’t have the fastest TIG machine and I’m nowhere close to thinking about an upgrade.. I just thought it would be really cool to have a 50 pound 120 V/240 V AC/DC MIG/TIG/ARC Machine that has variable hurtz. My wife gives me the gun law wait time of one month before purchasing. I use my welder about three times a week (6-10h). Wife’s suck when they are right, I don’t need it, I want it, So now I’m probably going to get a Miller MIG. The one month reactionary purchasing around here sucks.