Single takeoff to two mains?

jrj37_vt

Hi all,

I’m in the process of swapping out boilers and trying to make sure the near boiler piping is correct. The current system tees from a single takeoff into two mains going in opposite directions. Is this acceptable and keep as is or should I add an additional takeoff and separate the mains?

Thanks!

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bburd

Those two mains should come into the header separately.

109A_5

I'd support the mains to the building structure, you don't want to support them with the header piping. And get the jack out of the way, you can adjust them later if needed.

Long Beach Ed

As bburd says, the two mains should enter the header separately . Preferably the first (closest to the supply) should leave the header at 45-degrees, and ideally should be separated from the last boiler riser by a 14-inch nipple.

Cast fittings are preferable for steam to the malleable ones you are using.

If you can get that header up closer to the mains, you wouldn't need to drop the header. That would save you several fittings and their losses.

Nice job.

jrj37_vt

https://forum.heatinghelp.com/discussion/comment/1841830#Comment_1841830

Yeah that’s the plan - over time they had sagged so jacked up the mains and picking up some clamps to attach to the joists. Thanks!

jrj37_vt

https://forum.heatinghelp.com/discussion/comment/1841834#Comment_1841834

Thanks Ed! I’m using Burnham’s near boiler kit to try to simplify things (https://s3-us-west-2.amazonaws.com/catsy.782/Gravity+Return+Piping+Kit+Instructions.pdf) and was just trying to follow their recommendation. Thought a drop may also give us a little more maneuverability but now that I’m taking it so far back may not matter too much! Will definitely try to fit in a 45 and longer nipple past that last riser!

Long Beach Ed

https://forum.heatinghelp.com/discussion/comment/1841840#Comment_1841840

Do the best you can. Burnham's minimum piping requirements should get you good steam. Everything you can do above and beyond that will be a plus. The fact that you're asking and reading virtually assures you of having a good system.

delcrossv

I'll add to the choir: 1 takeoff per main. And take @Long Beach Ed 's advice about coming off at a 45 degree angle for at least the first takeoff closest to the supplies.

Steamhead

Looks like at least one of your steam mains is bigger than 2-inch. I'd make the header the same size as the largest main, otherwise the 2" piping will choke back the steam flow.

danmayer175

Curious - what is benefit of 45 degree angle for first takeoff? I haven't heard that before.

Long Beach Ed

https://forum.heatinghelp.com/discussion/comment/1841912#Comment_1841912

If the main has condensate returning through it and it leaves the header vertically, the condensate will rain down on the steam supplying the next main, cooling it. If it leaves the header at 45-degrees, the condensate will roll down the side into the bottom of the header and not rain down on the steam supply in the header.

In a counterflow main, it's most important to do this, or to drip the main to a return just before the header.