Differential loop found. Boiler replacement

McSteamer22

I found one!!
I know I’m suppose to leave it in service.
Any thoughts would help.
Current “b” dimension is 34”
Lowest crossover trap to waterline.
Floor to current waterline is 40”
New floor to waterline is 29”
I’m installing a megasteam 513 with the 3” 629 piping package.
Using vaporstat.
My required edr is 447.
All new radiator cage units and crossover cage units.
Thanks for anything. Finishing pictures coming tomorrow

Steamhead

On the Hoffman system, both the steam mains and the dry returns usually slope away from the boiler, and drop to the wet returns at the far ends. Just make sure the tees at the bottom of these drops are below the new boiler's waterline and you won't have trouble with steam jumping over to the dry returns.

I like to upgrade the crossover traps using 1/2" B&J Big Mouth units. These will get steam to the ends of the mains quickly. If one main is considerably longer than the other, use a B&J #122 on the short one to balance the two.

For the single main vent, I like the Gorton #2 rather than the Big Mouth. The #2 has a float that will hold back water if it gets up that high- remember, that's a "B" dimension rather than an "A".

Jamie Hall

What @Steamhead said. Try very hard not to change the working water line!

When you put the thing in commission, try a cutout of 7 ounces and a 4 ounce differential on the vapourstat -- but use a gauge to verify that the pressures are accurate.

McSteamer22

@Steamhead @Jamie Hall
How did I do?
Please be as critical as you want, I can take it
@dobro23

Steamhead

Like night and day. What main vent did you use?

Jamie Hall

Nice work there! Looks like you even managed to get the bottom cap of the Differential Loop off -- brave man!

McSteamer22

Two gorton #2’s

Jamie Hall

McSteamer22 said:

Two gorton #2’s

perfect.

Danny Scully

@Steamhead, I wonder if the tee where the vent branch begins is designed in some special way? If you look at it there seems to be an arrow and the bull of the tee is offset. I’ve noticed this on other installs as well with that model differential loop.

Steamhead

It is. That tee was designed to be used with the Hoffman #15 vent, which actually had its thermal elements located within the tee.

McSteamer22

I was also curious, its full port on the side that the arrow points, but from where the arrow starts it’s only about a 1/4 hole but threads on to 1 1/4, then down to the differential loop.

gerry gill

Looks great, only criticism is you need a better camera for such beauty