I managed to snap off the throttle outlet elbow in the center of my boiler, flush with the head. Extraction tools have failed, and careful grinding is not revealing the old threads. I just learned that Helicoil makes thread repair kits for 3/8" tapered pipe - has anyone ever used something like this in a high steam pressure application? I know the straight Helicoils stand up to IC cylinder pressure when used for sparkplug thread repair, but...

Kelly

SPARK plug heicoil does NOT rely on the coil to seal,,,the gasket on the head seals it,,,Will try to write more after supper,,,Ben

Check and see if you have room to drill and tap it out to ½ inch IPS 23/32 or you could go in-between the 3/8 pipe and the ½ pipe and go to a straight ¾-16 thread 11/16 drill.
You should have been using a forged steel 3000Lb rated ell. The first threaded fitting should always be at least a Sch 80 or better.

Original boilers used a straight thread.

Rolly



Edited 1 time(s). Last edit at 11/14/2008 12:27AM by Rolly.

I wish the person who had put this boiler together had thought of a forged ell. The car hasn't run since 1987. The boiler doesn't look like Don Bourdon's current ones - no rings around top & bottom. The edges of the heads are actually the largest diameter on the boiler, and it's got about a dozen tapped holes around the circumference, top & bottom, most of them with pretty old-looking plugs in them.

It's a 23" boiler with 720 tubes. They seem pretty close together - I don't think I could go to 1/2" pipe. How did they get a steam-tight joint with the straight thread?

Could I get away with welding the center hole shut and taking a 3/8 pipe out near the edge? Or would that end up warping the head around the middle and making the closest tubes leak?

Unfortunately I haven't been able to get it sealed enough for a hydro test yet - it'll be kind of ironic if the hole surgery is successful but the patient is no good.

Kelly

There is a method of EDM Electric discharge metal. To remove broken out threads.
Check out some good machine shops. I have never seen it done but it was a topic of a seminar I attended.
Rolly

Rolly

Kelly,
A couple of suggestions:
Heat the fitting up with a torch (getting fitting red hot is best) and then quench with water, use a hose and let the water run until the fitting is the same temp. as the water. You might have to do this a couple of times. The action is expansion and quick contraction to break loose the scale/rust locking the fitting in. Then resume use of your extration tools.
If you are too tentative with applying heat, repeat soakings with Kroil is your next best options.
Of course, if the above fails, you could always jsut use a tap drill size and drill the fiting out and then re-tap the hole.
Also the type/quality of your extraction tool is a factor as well.
Hope this gives you some ideas.
Regards,
Bob

One more thought.
1.You could use a tapered elbow with 1-1/2 degree taper.
2. You could plug the hole with a 1-1/2 degree taper plug. Pull another tube and tap the top hole and plug the bottom with a tapered plug ot tap it.
See attachment
Rolly

Rolly

On a Stanley boiler, only use the center of the tube sheet to pull your throttle steam from. If you pull it from a side, that would be a good way to get a slug of water if your Stanley was leaning to that side while driving. You can also accidentally prime out of the center hole but it is more forgiving than a side hole is. The throttle steam supply line, water level gauge, water siphon supply and the feed water lines should all be separated on the tube sheet by a reasonable distance. They will interfere with each other's function if placed too close to each other. Once I had the water siphon steam supply line too close to my water level gauge line. When I ran my water siphon, it pulled the water up though the water level gauge and it emptied my boiler as quick as if I had used a boiler blow down. I always carry a sharp small groving chisel and a hammer in my tool kit. Using great care, I have always been able to peel out a broken off pipe nipple where an easy-out wouldn't work. I always chisel out a notch on one side and then cave the broken nipple in on it's self. Great care has to be taken on preventing any damage to the remaining threads. The final step is chasing the threads with a pipe tap without making the hole any bigger. While out on the road, it seems that the 1/8" pipe nipples are the ones most often broken off in the hole.

Whew, throttle steam joint on boiler is restored. It took much carefully-angled grinding with a tiny Dremel stone to reveal the threads, then heat from a pinpoint acetylene torch caused the remaining thread material to separate nicely from the tube sheet. See attached photo - a triumph for my friend Gil and his friend Jim the machinist.

Thank you all for your help and ideas.

Thank goodness that technique worked there, because it failed in the other 3 broken-off holes. Fortunately there was space to make them all oversize.

So. I don't want this to ever happen again. Forged steel elbows for every boiler connection, McMaster's ASTM A576, Type 1214/1215 .

And - what have people used for thread sealer in this application? Is there something that seals, survives the fire for the blowdown fittings, and does not form a bond that's as nasty as the rust that I have just finished fighting?

And - are there any available strainers that I could fit just ahead of the blowdown valves? As much as I tried to keep the vacuum going during drilling and tapping, I'm pretty sure that some junk dropped in, and I'm guessing it will all eventually find its way to a blowdown valve seat.

Kelly

Dear Kelly, Rolly turned me onto a high temperature anti-sieze/thread sealant that I use. It was posted here on this forum years ago. My bottle is out of view right now so maybe Rolly can chime in here and update my posting. Don't fret about the shavings in the boiler. A new boiler is prety well loaded with shavings and the shavings quickly disolve into the rusty water and are passed during blowing downs with-in the first 2,000 miles. I use 1/4" schedule 80 stainless steel street elbows for my first blow down boiler fittings. They are easily cleared from any blockages without having to drop the burner. Only very rarely would you ever experience a blow down blockage. When you do get a blockage, it is sediment from some bad water that you had picked up along the way. All the more reason to blow dow at the end of every day. The boiler level reflex sight glass should always be showing water movement in it. When the water level stops moving, it is time to get out and blow down the blockage from your sight glass.

This is the stuff Pat and Kelly
[www.herchem.com]

Rolly

Thanks. Sorry for the repeat question - here's the original discussion of anti-sieze: [stanleysteamers.com]

If it's not taking this thread too far off topic I'd like hear some thoughts about the anti-seize...Or, if needed I can resurrect the anti-seize topic.
Here goes:
The sealant Rolly recommended is good to 500F. Saturated steam temp. @ 550 psi is 477F. That only leaves 23F of a cushion if you have any superheat at all coming out of the throttle tap. Granted the tap for the throttle is prior to the steam going through the super heater.

I am a big fan of the high temp. anti-seize like Loctite C5-A (there are others) that is good to 1800F (way more than plenty), I would think you would get some "sealing" from this plus your galling problem is taken care of.

Another thought: What about white lead? I don't think it is commercially available anymore but I have some I grabbed while a place I worked was clearing out "hazardous materials". Would that be good for those types of temps.?

Bob

Bob
I use Jet-Lure Nikal anti-size good for 2600F on all my stainless steel pipefitting superheat ecc. and also on all the brass flaring nuts for the copper tube. I haven’t had any problem with it leaking as a pipe dope. But its not rated as a pipe dope.
I also use Red Silicone 650 on all nuts and bolt threads so they wont come apart from vibration also on hubcap threads, the stuff never hardens, you have no problem taking things apart.

This one is good for 800F I have never used it. I do have another one of the same brand good for 600F
[www.gasoila.com]

Rolly



Edited 1 time(s). Last edit at 12/04/2008 06:39PM by Rolly.

Not helicoil related, but I thought I'd follow up with what the boiler is doing.

I'm learning an interesting lesson about hydrostatic pressure. Well, two, actually, but we don't need to go into the first one...

My water supply is an outside tank, and it's getting cold here. I was rushing to try to do one hydro before draining everything. The tank was freezing and required some external heat to get it to start running. The garage was about 31F, judging from how spray was behaving.

I filled the boiler, pumped it up to 700 psi, and watched water in small drips from the bottom of some tubes, and water oozing from top & bottom of quite a few tubes. Down to 600 psi in 45 minutes, down to 520 in 2 1/2 hours, to 510 in 5 1/2 hours. Water lying all over the top & bottom heads - pretty disappointing.

I didn't want to start draining in 20 degree weather, so I threw some blankets over the boiler and put a small heater underneath to keep it from freezing. Came out in the morning to see if all the pressure was out - and found the boiler at about room temperature under the blankets, dry - and showing 610 psi. 10 hours later it was showing 725 psi. I turned back the heat a little to keep from ruining the 600lb Stanley gauge that was unfortunately also connected to the system. 5 hours later it was 730 psi.

Apparently warming the boiler up from freezing was enough to seal the leaks, and just the expansion of water due to the ~40 degree temperature rise was enough to raise the pressure 200psi!

It hasn't experienced the old standard of 2x intended steam pressure, but hopefully it's sound enough to use. Whew...

Kelly

Hi,,,My recolection of test pressure is 5/3 of working pressure,,Sounds like time to light pilot an go round the block,,feed plenty of oil and get the engine hot and lubed,,, I think that one has a crank on the oil box to feed extra oil,,madison Kipp ?? i can't recall,, Have you assembled the burner yet ?? Best of luck,,Ben ,,Will Rolly or others comment on this,,Ben

Ben the ASME code requires a hydrostatic test 150 percent of the designed working pressure. But your dealing with a non-code design with a Stanley boiler. In many states such as Rhode Island all boilers are required to be tested, (at the will of the inspector) The ASME code has a hobby boiler section that requires non-code boilers be hydro to three times working pressure.
The thing is the ASME is not a government organization, only used and recognized by the National board and many other as a standard for safety. In most States its up to the local inspectors. The most important is the insurance companies that may hold the automobile insurance on your vehicle. Every one looks for a scap goat and goes to the SAME code. If you’re operating it you should be looking at your own safety and those around you.

Rolly

The leaking fire tube results are typical. Copper expands faster with increased heat than the steel tube sheets do. As the temperature increases, the copper tubes get tighter in the tube sheet. Typically, when I swage a cold boiler, at 600 pounds I will have about 8 tubes that will still show moisture and they will drop a drip of water about one a minute. At 300 pounds cold, they don't leak at all. Rather that to beat the stuffing out of them to get them totally tight, I let them go. When there is heat in the boiler, they will be tight at any pressure. When a boiler really is in need of tube attention is leaking, and the fire is on, the copper fire tubes are usually still tight from the fire. After the fire cycles off, then they may start dropping their water and putting the burner's fire out. I was on a tour once in Indiana, and my old boiler had several copper tubes that would drop their water after the fire cycled off. I ended up hand firing the boiler to keep a steady fire on the tubes to keep them tight. We finished the tour by hand firing and it took a bit of work, but it was worth it. I replaced that ancient boiler when I got back home. It didn't have enough copper left in it to swag tight anymore. It was the one boiler that I have even turned upside down to make it last a little longer. Turning it upside down gave me another year out of it.