Just because it's been that way for years

Steamhead

does NOT mean it's right!



We're working on de-knuckleheading this one-pipe steam system. It had a banging problem, dead main vents and numerous leaks which we knew were related to the banging. Once the asbestos was removed we could see why it banged.



The steam comes from the boiler thru the 2-inch pipe, and the pipe size was reduced at this tee that looked original to the system. The pipe coming off the bull is 1-1/4", and the run is only 1"! The 1-inch tee looks like it was added later, hence the union. Of course, when we took it all apart we got a lot of water.



The house was built in the 1920s. Looks like this is the work of a less-than-proficient Dead Man.

Steamhead

The fix

involved keeping the main at 2" until it reached the brand-new eccentric reducer. We cut and threaded the 1-1/4" branch in place.



We're also redoing the near-boiler piping- it was typical of the messes we're so tired of seeing, so I didn't take a pic of it. The new 2-1/2" header is shown. We didn't drop it since it only uses one riser. The boiler is a Dunkirk atmospheric, rebranded as a Smith.



This job will also get new return lines, a Hydrolevel VXT feeder with counter, new and properly-sized main vents (the one for this main is on the 1-1/4" branch) and a Gifford Loop, needed because there's no way to run the returns low enough to be wet or high enough for a decent "A" dimension if a standard Hartford Loop is used.

Charlie from wmass

yep not all tradesmen were.

I often marvel at the fact the one pipe steam was the cheap job of its day and installations often show it.  Two pipe Steam, Vapor,and ultimately Gravity Hot water were the ways to go for high end work and efficiency. NIce work as always. The one pipers can be so nice when done right.

nicholas bonham-carter

gifford loop?

can you please explain the effect of the gifford loop, in regards to lack of height, and depth? as i recall, it is not very different from the hartford loop.

i once saw this on a website, but now cannot get back to it!--nbc

Unknown

Gifford Loop

NBC-  Here's  copy of the article on the Gifford Loop.



Steamhead -Can you tell us how well does this work in practice?

Steamhead

A Gifford Loop

is a Hartford Loop where the return comes into the equalizer above the normal waterline. This can be used when you need to keep the returns under water, but you don't have the height for the usual False Water Line.



I believe the "Gifford" refers to Henry Gifford.



Watch for a pic when we finish up.

Steamhead

This one

is the first I've done in a while. But I don't remember any problems with them in the past, they've worked as intended. Of course, we'll keep you posted ;-)

Gordo

One Pipe Steam And The Low Bidder

We've noticed on one-pipe steam jobs, and even two-pipe steam jobs, that the pipe was almost never reamed.  Gas pipe also wasn't reamed much of the time, it seems.



 On many jobs,  only the minimum number of threads were cut to make up the joint.  The Dead Men (Peace Be Upon Them) were under the same pressures we are today to "git 'er done" and for the least cost.



We also suspect  that cast iron fittings for steam were not used by the Dead Men (PBUT) for ease of repair by us in their future,  i.e. cracking the fitting to save the threads,  but because cast iron fittings were cheaper.

gerry gill

they have the right people

on the job now..bet it will be real quiet after your done!

nicholas bonham-carter

unreamed pipe?

can anyone elaborate on the effect of unreamed pipe?--nbc

Gordo

Effects of Un-reamed Pipe

Un-reamed pipe is a drag, literally, on the fluids flowing through it.  It is the commutative effect of all those little pipe-end restrictions in every joint starting at the boiler and on out to every radiator, every cycle, year in and year out.  More total restrictions means a higher pressure is needed to get the steam to flow    More total restrictions means it's a bit harder for the water to flow back down the pipe to the boiler.  Add that up over 80+ years...



That's why we ream every pipe end we cut.

Steamhead

Gifford Loop Pics

finally. The last one is the reason for the Gifford Loop- we had to run the new return on the same ledge that held the old one. This was well above the boiler's waterline.



The system heats much better, especially since we flushed a LOT of dirt out of the boiler. But now that we're making dry steam, we found an off-pitch runout that has a bit of "snapping" water-hammer, and some concealed second-floor rad piping that's holding some water up in it until the boiler shuts down- then it all runs back. We'll get to those next time- for now we're sticking with manual feed to keep the boiler from flooding.

Unknown

Gifford Loop

Steamhead-  In relation to the normal waterline, how did you decide at what height the return should join the "Hartford Loop" ? (Meaning the height where the close nipple is attached.)

I haven't quite mentally figured out yet how in practice the Gifford loop operates.

I'm assuming that since the Gifford close nipple entry  to the "Hartford loop" piping is above the water line, that when filling the boiler it won't fill the wet return too like the Hartford loop  would do so  you have to prime the wet return through an operation or two to get the boiler waterline level stable? Am I making sense? Overall are you happy with the Gifford loop concept?

Nice looking job!  Thanks for sharing your experience with us!

Steamhead

Simple

we found the highest point in the return line (which is at the drip) and set up the Gifford Loop at a slightly higher point. Now the "A" dimension is at the vertical drip rather than the horizontal return, and the steam can't get to the horizontal return and cause banging.

We piped the water feed line into the return so it would fill the Gifford Loop first, then the boiler.

Unknown

Gifford Loop

Thanks Steamhead . That makes good sense!