Making strong, leak-free, correctly-angled pipe joints - how?

Precaud

I'm a newbie to plumbing. I've installed chimney liners, fixed faucets, and cleared drain traps. But redoing the piping (it's all 1/4" brass) for my boiler's pressure sensing hardware (Pressuretrol and gauge) has me stumped.

When working with combinations of angled pipes, tees, elbows, pigtails, etc. How in the world do you get strong, leak-free joints AND have all the angled pieces coming off at the correct angle? It's been a real crapshoot for me so far.

Thanks.

mattmia2

brass is a little harder to get to seal than steel or iron, i usually use teflon tape and 3 or 4 turns of it and dope on brass. since you are working with a steam boiler and the oil in the dope would cause water issues until you skimmed it off, you might want to try tape only. (maybe others know why brass seems to be harder to get to seal, maybe because it is more brittle and less malleable than steel or iron)

just feel when it starts getting tight and stop when it is at the angle you need it at. you can usually back it off a couple degrees if you need to

EBEBRATT-Ed

@mattmia2
Takes practice, pretty hard to describe it's just something you learn to do.

Some tips:

Know your "make in" ........the amount a pipe or nipple make into a fitting. It changes with the diameter of the pipe...for instance 1/2" pipe is about half an inch. 4" pipe is about 1 1/4"

There are charts available but just take a nipple and dope or tape it and screw it into an elbow or tee and tighten it up, then take it apart you will see how much it screwed in.

Most of the time this allowance will work for that size pipe. But there's tollerence's in manufactured fittings and in pipe so nothings perfect. Some times you will figure out which nipple to use and it won't fit and you change it to a longer or shorter fitting. Generally the pipe or nipple will screw in right to the end of the threads in the fitting but not always the case.

You can usually figure out what you need by screwing you fittings together "dry" with no dope to get from point a to point b but you have to consider when the fittings are tight the lengths will change

Precaud

Thanks for the pointers, guys. I'll try doing a dry layout before "improvising in place".

mattmia2 said:

brass is a little harder to get to seal than steel or iron, i usually use teflon tape and 3 or 4 turns of it and dope on brass. since you are working with a steam boiler and the oil in the dope would cause water issues until you skimmed it off, you might want to try tape only. (maybe others know why brass seems to be harder to get to seal, maybe because it is more brittle and less malleable than steel or iron)

I haven't used any dope yet. Seems like not fun to deal with if/when you need to disassemble it down the road. 3 or 4 turns of tape... I'll definitely try that. I've been doing two.

I thought brass is softer than iron and steel, no?

Long Beach Ed

First, with threaded pipe, we never use anything from China. The threads are very often poorly cut and sometimes the alloy is so poor the threads pull out when tightened properly. There are also common pinhole casting leaks. Though slightly better, we avoid Taiwan also.

We use a level on just about every pipe and calculate every offset length.

Fittings are torqued properly, permitting two and one-half threads to show. We use Teflon pipe dope. Never had a leaky threaded joint or casting leak in many thousands following these rules.

This adds expense, but our labor or leaks are much more costly than quality materials. All our work is commercial or military contract which do not tolerate failure or import junk.

If saving money's a priority to you, the Chinese stuff will work perhaps 90 - 95% of the time. The poor quality control will eventually get you a leaky part or an elbow that's drilled at some weird angle, while poor metallurgy will leave you with chunks and galls in your threading .

EBEBRATT-Ed

@Long Beach Ed

I don't know the last time I saw anything made of brass that wasn't China or Taiwan.

Precaud

Only buying USA-made stuff is going to be very difficult, @Long Beach Ed . Just finding the correct part locally is quite a challenge. At ACE Hardware yesterday, all of the brass is from China.

mattmia2

Brass is softer but more brittle.

In my limited experience I have had problems with getting asian ground joint unions to seal but not with threaded fittings but I have seen some with either tappings or castings at odd angles (the tapping isn't square to the flange but it wasn't clear if the tapping was off or the casting).

Precaud

OK thanks.

It occurs to me that the real problem happens with 45º and 90º elbows. There's only one thread position that works for the needed angle position. I can see that using a tee instead of a 90 would increase the likelihood of strong + leak-free; just plug the unused end.

Is there a similar technique for the 45 ?

JUGHNE

Have you considered using the tapping that the relief valve in on?
You could remove the valve, add nipple and tee. Put the (new) valve back on top of the tee in the same position/direction it is in now.
Then come out of the side of the tee with reducers to get to the need 1/4" pigtail.......tee......90... gauge....nipple to control.

This location gets those items well above any sludge of the boiler. And you could probably benefit from an new 15 PSI safety relief valve also.

Long Beach Ed

We use brass from Thailand or Italy, but generally order lot quantities from Ward, made in USA. Yes, USA brass is very hard to find if you only need a few pieces. In a pinch, we've found that anything is better than China. Italy and Thailand seems to be pretty good and has never given us a problem.

Those with no choice but consumer stores have a problem finding real stuff. Like using consumer-quality tools, the junk they sell frustrates the less-experienced homeowner who might otherwise be able to tackle the job. It's very frustrating when we have to find one piece that we don't have in stock.

We wouldn't even think of trying to work with those cock-eyed elbows from China.

Precaud

JUGHNE said:

Have you considered using the tapping that the relief valve in on?
You could remove the valve, add nipple and tee. Put the (new) valve back on top of the tee in the same position/direction it is in now.
Then come out of the side of the tee with reducers to get to the need 1/4" pigtail.......tee......90... gauge....nipple to control.

This location gets those items well above any sludge of the boiler. And you could probably benefit from an new 15 PSI safety relief valve also.

That's a very interesting idea, @JUGHNE . Never thought of it. But yesterday I saw the possibility that the inline pigtail + Ptrol + gauge was going to be too tall to fit inside the front. I was thinking I might have to drill a hole in the top cover and run a 12" nipple up to it. And taking the 45º feed off that tee would have to support the entire weight of it. But your approach makes MUCH more sense. I can still use the tee feed for the 30psi meter mounted on the cabinet, to satisfy code.

Your suggestions are always so practical. Thanks again.

JUGHNE

Just so all your gauges and controls are protected by the pigtail.
I have had good luck with 1/4" SS fittings, even the China ones......the only exception being unions sometimes.

If you use a black 3/4" cross right on the top of the boiler with side plug, then tee up with plug on side, you then can check for blockage by removing plugs.
Then with brass, copper or SS from that point up you have less chance for blockage.

Precaud

Thanks for those details. So you want a pigtail, even when coming off the top like that?

I like your cleanout idea.

JUGHNE

If you put your hand on the bottom of a pigtail it will burn you.
Above the pigtail full of water the piping is cool.
The steam pushes against the water loop, the water loop pushes against the air trapped above it under the devices.

The water loop protects those devices from the boiler water and the steam temp. That is why you need to prime the loop before use.

Precaud

OK, got it.

Precaud

JUGHNE said:

If you use a black 3/4" cross right on the top of the boiler with side plug, then tee up with plug on side, you then can check for blockage by removing plugs.

I decided today to go in the direction you suggested, and ordered all the needed parts for it. Will post a pic when it's done. Thanks again for your advice!

Precaud

Here's the pressure monitoring hardware, relocated on top of the boiler, as per @JUGHNE 's suggestion. I'll watch it tonight for any pressure indication on the meter, and if all is well, wire up the Ptrol tomorrow.



I'm not crazy about how prominent and exposed the whole thing is, including the wiring to come. But if it works properly, I'll live with it.

mattmia2

Another tee or cross somewhere so you can flush water through the pigtail without taking the gauge or pressuretrol off would be nice.

neilc

and don't forget to pipe that safety valve down to 6 inches off the floor,
if it ever blew, , ,

Precaud

mattmia2 said:

Another tee or cross somewhere so you can flush water through the pigtail without taking the gauge or pressuretrol off would be nice.

OK, I can replace the 90 under the gauge with a tee. But wouldn't you want to remove and inspect the bottom of the Ptrol at the same time anyway? That was my thinking.

neilc said:

and don't forget to pipe that safety valve down to 6 inches off the floor,
if it ever blew, , ,

Interesting. The original install did not pipe it, but I see your point, thanks. Does that pipe have to be metal?

neilc

not sure,
I would do metal, threaded black,
but I have seen plastic / pex

Precaud

OK, thanks. Given that the top of the boiler enclosure hasn't been cleaned in over a decade, maybe I should just leave it as it is... a nice steam bath could be a very good thing

mattmia2

if your code follows the model code, the relief valve piping has to be a material that is rated for the working temperature of the system, which i think in the case of steam means metal. on lower temp hot water systems you can use cpvc.