Main Vent

RobG

What is the lowest you can tap into a main (clock angle). As long as the main is well pitched and the tap is above any condensate path I can't see a problem. As long as the threadolet is angled upward to prevent any condensate trap.What say ye? I don't need to do it but another thread got me to thinking. How low can you go?



Thanks,

Rob

Steamhead

Anything lower than halfway down

will allow water to back up in the vent piping. See my signature pic for an example.

RobG

Next question

For the next question, at what sizes do you drill and tap verses installing a threadolet? And do you braze or weld?

Steamhead

I generally

drill and tap up to 1/2-inch pipe thread. Drilling becomes very unwieldy in larger sizes, so we call in the welder for these.

JUGHNE

Drill & tapping questions,

I'm thinking of tapping the tops of two  2" steam mains with  3/8" nipples (2 per main, 4 total) and installing Gorton #2 on each 3/8" nipple.  What oil/lubricant is suggested for the drilling and tapping?  I'm concerned of getting oil into the steam mains.  Although the boiler most likely needs skimming/cleaning anyhow.

Thanks

ChrisJ

oil

If drilling a cast iron fitting like an elbow or a tee I wouldn't use any.

Now that doesn't make it right, just when I drilled my last ell I didn't use any oil.    I'd rather burn up a bit and damage a tap than have to deal with oil in my boiler again.



I'm replacing a fairly long length of pipe soon and need to figure out what sealer I'm using on the threads.  Because it's going into an 80 year old ell I'd kind of like to use blue monster tape and megaloc, but can't stand thinking about oil in the dope ending up in the boiler.   I plan on scrubbing the pipe with dish soap and hot water in the back yard before threading it in.

I'm tempted to use RTV.

Hap_Hazzard

I'd use oil.

Especially on a fitting. Cast iron is high in carbon and it's brutal on drill bits. Most of it will come out with the chips, which, if you use the right feed pressure, will be two long spirals. I'd also oil the tap. If you're drilling into pipe to weld on an olet, all the oil's going to burn off anyway.

ChrisJ

Cast iron

Now I don't know what to think.

A machinist told me cast iron is very soft and drills and taps super easy.  He also said it always crumbles, it's just the way it drills.



The last time I drilled into an ell it was extremely easy without oil.

ChrisJ

Perhaps

Does this include 80 year old pitted and rusty fittings though?

On brass connections I would tend to agree.

Hap_Hazzard

He must've been pulling your leg.

Grey cast iron does tend to be brittle, but most of the fittings you see these days are malleable, which is annealed white iron. Both contain a lot of carbon and silicon in large crystals that are very abrasive.

ChrisJ

Nope

Don't think he was.

The fitting I drilled was from the 1920s and all of my newer fittings are Ward cast iron fittings.



I don't think these are considered "malleable" are they?

Hap_Hazzard

I'm sure they make both kinds.

I think the rule of thumb is if it has teeth marks from pipe wrenches it's malleable; if it doesn't it hasn't been used yet. :-)



Cast iron might chip, but it's just as likely to take a tooth off the wrench jaw.



Another difference is, if you're screwing a street fitting into a female fitting, you can turn the malleable fittings a little after they get tight to line them up, but cast iron will stop dead. If you force it it'll break.



Also, I think unions are always malleable.

ChrisJ

Unions

From what I see on Ward's site the only cast iron unions are flange type, I guess that isn't a surprise.



I'm also surprised to see pexsupply aka supplerhouse no longer stocks cast iron ward fittings.  :That's where all of my cast iron fittings came from.



Now where will I go.

Hap_Hazzard

Get with the program, dude!

I don't see what you have against malleable. They're much more forgiving of inexperienced weekend warriors like us, and frankly, I don't really get why the pros like them. Maybe they aren't as strong as the cast fittings, but they'll outlast any pipe you screw them onto. They'll probably outlast you and me too.

Hap_Hazzard

Light cutting oil or a gel

The thicker and stickier the better. Not only will it not run into the pipe, but it will probably keep most of your chips from falling inside--not that that's a big concern here.



You might see if you can pick up one of those lube sticks they make for bandsaws.

ChrisJ

Cast iron

Really? They must have changed their search engine because it used to be fittings > cast iron.



As far as why use cast iron I believe it's because you always have a way out by shattering it if need be.



I used all cast iron on my install because that's what the pros said to do.

ChrisJ

Nice!

Thank you!



And now I wish I could forget how much these cost again.  I remember being amazed at the time how much it cost to pipe my boiler using parts from an online store.

http://www.supplyhouse.com/Ward-FCITE3x3x2-3-x-3-x-2-Black-Cast-Iron-Steam-Tee-533000-p

Hap_Hazzard

Have you ever had to?

I can't imagine myself shattering a piece of cast iron on purpose. I suppose if I had to I could cut through a malleable fitting with a reciprocating saw, but I'd rather cut the pipe.



If you really had to you could probably make a malleable fitting shatter if you chilled it with liquid nitrogen. You do keep a bottle of that stuff handy, don't you? :-)

Hap_Hazzard

Ward

Ward has a credit application on their website. :-D

ChrisJ

Not yet

I was able to remove the nipples from the elbows on my two mains.

But I'm told you cover it with a good heavy rag and then give it a few good whacks with a lump hammer and you're in business.

Hap_Hazzard

I'll watch.

I'll buy a new cast iron fitting and let you use my best hammer (Mjölnir), and I'll bet you a sixpack of Sweet Baby Jesus you can't break it.

ChrisJ

Come on down

To NJ and I'll buy a 12lb sledge just for the event.  That fitting is going down!

Hap_Hazzard

Oh, you wanna use BOTH hands?

If you're going to use a sledge, let's make it more interesting. We'll connect a couple sections of pipe, hang it over your head, and see if you can break it without damaging the pipes (or anything else that might be in the area if it were in a typical basement).

Charlie from wmass

I crack them often

What is the big deal? make it a case of "old engine oil " and I will call the number of swings.