Pumping Into An Elbow

[velvetfoot]

I'm adding a feed pump to my oil boiler (paralleling with new pellet boiler). Space is tight. It will be pumping to boiler return, and close to the boiler, mounted on a vertical section of pipe, pumping into an elbow which, after it turns, goes several feet horizontally to the boiler. Pipe is 1-1/4", and there are isolation flanges.

Will there be a problem with this? Again, space is tight.

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[BoilerMan]

Generally it is good practice to have 5-10 pipe diameters after a circulator. It is also best as I know you know to pump away from the expansion tank. So.........the best place for the expansion is on the boiler supply, and then the circulator after than then 5-10 pipe diameters then elbows and stuff.

TS

 

[velvetfoot]

Would it be different as far as 5-10 pipe diameters when pumping to the return, since the water has given up some of its energy?
Space is real tight and I'm planning on putting the pump near the oil boiler return.

 

[Bob Rohr]

Would it be different as far as 5-10 pipe diameters when pumping to the return, since the water has given up some of its energy?
Space is real tight and I'm planning on putting the pump near the oil boiler return.

With the flow rates you are working with, and a low rpm pump, you could fudge on that rule of thumb a bit. After the ell you are flowing into a wide space, any potential turbulence will dissipate inside the boiler.

Do stick to that rule on the suction side of the circ, any restriction or tight fitting can lead to cavitation.

 

[velvetfoot]

Thanks.

 

[BoilerMan]

With the flow rates you are working with, and a low rpm pump, you could fudge on that rule of thumb a bit. After the ell you are flowing into a wide space, any potential turbulence will dissipate inside the boiler.

Do stick to that rule on the suction side of the circ, any restriction or tight fitting can lead to cavitation.

Bob is absolutely correct!

TS

 

[DaveBP]

You might be able to mitigate any bad effects of a 90 by using two 45s connected by a close nipple in its place. If you have that much space.

 

[velvetfoot]

It is also 1.25" pipe and not big pump so that should slow things down. The pump is an Ecocirc Vario, so that can be dialed in. Looking at the pretty big isolation flanges, I think I had 5 diameters min. I'm hoping for the best. Space is tight.