Oil steam re pipe

Dave0176

Got a little job to fix a bunch of deficiencies, like adding Emerg switches at all entrances adding a second LWCO with manual reset and install a Hot water tempering valve. It’s a commercial building that’s why the state inspects. In the process almost all the soldered copper joints were leaking as were most of the wet returns. Dang oil company didn’t want to fix the copper, told him it’s steam what do you expect, he basically didn’t want the contract anymore so the building owner found me on here and it’s in my town around the corner, can’t get better than that. I got most of the work done going back for wiring.

nicholas bonham-carter

You mean the inspector actually looked at the boiler and piping?—NBC

Dave0176

nicholas bonham-carter said:

You mean the inspector actually looked at the boiler and piping?—NBC

Nah his complaints was the need for a second low water cutoff and switches at all entrances. The building owner asked me about the piping.

BobC

Beautiful work as always, your customers are lucky to have you.

I have a run of copper going to an upstairs bath with a small 22 EDR in wall radiant radiator. I think the fact there is over 20 ft of of 1" copper makes the expansion of the pipe survivable. The pipe is probably on the crawly edge as far as capacity goes but that little guy is the first to heat upstairs. Replacing it would entail tearing up walls and ceilings, It's been there for at least 40 years so for now it's fine.

I've always used a 4" box with a duplex receptacle and emergency switch. The outlet is always on so power is easy to reach at the boiler and besides that it's a handy place to plug my old grind wheel in.

Bob

EBEBRATT-Ed

@Dave0176

Going back for the wiring? what's wrong with it LOL. Nice job as usual. In MA. the state inspects over 250,000 I beleive

jumper

Do approve redundant safeties like second LWCO.

retiredguy

I never liked both pressure controls on the same pigtail. Other than that, the installation looks great.

dopey27177

Don't take my comment to be negative.

With the height of the header above the boiler a drop head header is overkill.

What I do applaud is the use of fittings made in the USA'

Ward is a fine old fitting manufacturer.

Jake

Danny Scully

@dopey27177, a drop header is never overkill...increasing the riser out of the boiler, however, may be (as this doesn’t decrease the velocity out of the boiler). 

EBEBRATT-Ed

@Danny Scully
How can increasing the riser size not decrease the velocity coming out of the boiler?

Danny Scully

@EBEBRATT-Ed, the size of the riser tapping in the boiler determines the velocity. 

Jamie Hall

There's a good deal to be said for maintaining exactly the riser tapping size all the way up the riser and on over to the drop header (or up to the steam drum, should you be so lucky as to have one!). That way any entrained water stays entrained until you get to where you want it to slow down and get out of the way.

Precaud

dopey27177 said:

Don't take my comment to be negative.

With the height of the header above the boiler a drop head header is overkill.

I have wondered about this, thanks for bringing it up.

Is there any measured data to support the use of a drop header in all circumstances? Or is it all anecdotal/conviction?

Jamie Hall

I doubt there would be hard and fast data to support a drop header, since while the extremes are easy enough to see, the inbetween is hard to see -- and almost impossible to measure.

The objective, of course, is "dry" steam -- but the question is how dry is dry? Since we are almost always dealing with saturated steam, and since there will always be some condensation in the piping, even with insulation, what is meant by "dry" steam is more an absence of carry over droplets than truly dry steam -- which you can only have with superheat.

So. If your header itself is big enough to allow any carryover droplets to drop -- velocity low enough (again, you'd have to experiment -- is half the velocity in the risers slow enough? A quarter? The length of the header comes into it too, and where takeoffs are located) you probably don't need a drop header, although one will always improve things. Question is, how much?

dopey27177

My first run in with a drop header was 55 years ago.

The boiler was installed in a crawl space. There was not enough room to install the header 24" above the boiler water line.

The drop head header was installed at about 15 " above the floor and a float and thermostatic trap was installed and piped to a 20 gallon boiler feed pump. The call I received was no heat in the building.

I knew nothing about drop head headers. What I did find was the float was collapsed and the pump would not come on line.

I made a temp. repair with a float ball from a toilet tank. After locating a float ball for the boiler feed pump I went back and made the permanent repair.

After a bunch of phone calls to boiler manufacturers I learned where and why the drop head header is needed.

In all my years in the business I never seen another drop head header.

Today when you look at the specs for a boiler installation most boiler manufacturers show the drop head header.

The most prudent way to install a boiler is to make that install as the boiler manufacturer recommends.

There is no method to install a boiler that has long term good results when you deviate from the proper near boiler piping install.

Some times boiler manufacturer show a reduction in the boiler tapping on small boiler installations. I do recommend that full sized tapping and or tapping's be used for all near boiler piping installations

Jake.