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distants to air scoop

ScottMP
ScottMP Member Posts: 5,883
and Chris brought to my attention the directions for the Amtrol air purger (Technical data).

It states that the air purger is to be located " as close to the boiler as possible " ?

I was told that 18" was the distance neccesary on the horizontal, for the air to rise to the top of the pipe, after the riser, and allow the maximum air elimination.

It certainly makes sense to me that a distance would allow the air to rise to the top of the piping, but maybe Amtrol dos'nt think that way.

Scott

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Comments

  • dave connors
    dave connors Member Posts: 30
    air scoop

    The 18" distance is necessary due to the turbulance created by the elbow at the top of the supply riser. Try a Spirovent and you wont have to extend your manifold 18".
  • Firedragon_4
    Firedragon_4 Member Posts: 1,436
    I agree on both points and

    I was always taught that if it's less than 18" it's a cross or tee at best. Very surprised to hear otherwise.
  • J.C.A._3
    J.C.A._3 Member Posts: 2,980
    Honest to God!

    Scott has the instructions HIGHLIGHTED, in front of him. This is what I read today while doing the install.

    I. too was always taught the 18" rule. Last week , I installed a B&G air purger, lo and behold, no such instruction was in their literature either.

    Have we got some mis-direction from "hearsay"? I was installing a new product and read the instructions. My guess is they have WAY more time to futz with these things than I do, so I'll follow the manual.

    Thanks for bringing this up Scott. After my short remarks this afternoon, I thought you might like to see what I've been looking at .(Drilling through that 10" foundation with "pipe wrench elbow" having reared it's ugly head after a 3 year absence, wasn't much fun. Sorry for the curt responce)

    BTW Dave, it's a G115/28. I know you like BLUE! Chris
  • kevin coppinger_4
    kevin coppinger_4 Member Posts: 2,124
    I think what they mean....

    is close to the boiler as reasonable. 18" is correct. But put it on the supply side where the water is hotter and air will come out of solution better as opposed to the return side...kpc

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  • J.C.A._3
    J.C.A._3 Member Posts: 2,980
    One other thing....

    Amitrol has a different inside design than most of the other "scoops" I've seen. There appears to be 2 difuzzers inside the unit, one going up and one going down . The instructions were quite clear.

    Watts/Wolverine and Taco seem to have a single "seperator" in their product. B&G's unit looked to have a "restriction hole"in theirs. The B&G also had a 3/4 tapping for the vent can/air eliminator, no seperator or scoop type difuzzer. I kind of like that one. Seems to me that the restriction would hold the water there for a bit, and give it a chance for the air to seperate, maybe even keeping the PONPC a bit more consistant.

    Just some personal observations. I still will follow the installation inserts. Like I said, they have more time to play with this than we do. Chris
  • Milne
    Milne Member Posts: 15
    Dave

    I think a Spirovent is a great product, but on a boiler piped properly, its unnecessary.

    I have NO problem with the 18" rule. We try as best as possible to stay within it ( 15-16" not really a problem ).

    Also a boiler properly pumping away Also has No need of a spirovent.

    Scott
  • Mark Eatherton1
    Mark Eatherton1 Member Posts: 2,542
    18\" rule...

    I've seen it in Amtrols Specification Engineering book, but NOT in their installation instructions...Seems to me if it were REALLY critical, they'd include it in their installation instructions.

    My thoughts on it are this. The applications engineers assumed that the devices would be running constantly at their peak flow rates. Under this scenario, 18" of straight pipe is critiical to ensure bubble entrainment on the top of the pipe. In reality, the chances of the system running at full tilit are slim to none...

    I've done MANY installations with conventional scoops, and in 99% of the cases didn't provide for the theoretical 18" straight pipe before the seperator, and I've never had an issue. Now in the case of my own home, I used a popular MBR (micro bubble resorber) and it has 18" of straight pipe before and after it, and when I first started my system, I had a bubble working its way around the system that the MBR could NOT trap and expell. I finally injected about 2 ounces of liquid detergent (Dawn) and the bubble disappeared...

    Whodathunk...

    Provided that you're not running the scoop on a primary loop where the water is screaming around at constant max velocity, I think the 18" rule is overkill. If you do a good job of initial ppurge, and you're pumping away form the PONPC, things (remaining bubbles) will work themselves out in short order.

    ME

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  • dave connors
    dave connors Member Posts: 30
    Ah...is spirovent unneccessary or just expensive?

    Of course as americans we want something for nothing which is why the Europeans are always a step ahead. If ya scub the air outta the water it will absorb bubbles outta the system. Thats because naturally water is 11% air.hmmmmmmm
  • jackchips_2
    jackchips_2 Member Posts: 1,337
    Ah, expensive

    or just trying to make more off a customer?

    Which question is more relevant-yours or mine, Dave? Or maybe neither, I ask rhetorically, as I'm sure you are also.

    As Mr. Milne, I have not had an air problem in any system that I have installed pumping away. Nor has any of my friends who have had their system installed that way.

    Jack
  • dave connors
    dave connors Member Posts: 30
    a man of character

    Nice to see someone looking out for the pocketbook. I must admit that i tend to be a penny pinching energy bug. I always assume that we should do our all to lower our dependence. Circs do a great job pumping water and a lousy job pumping air. This saving is greater of course as the circs get larger. I field calls all of the time concerning air but I will assume that this is the vocal minority.
  • Milne
    Milne Member Posts: 15
    expense

    is not the issiue.

    All the jobs that we do are pumping away from the point of no preasure change. They all have an air scoop installed as close as possible to the 18" rule. We have NO problems with air inour systems. I see NO reason to install a MBA if it is not needed.

    I have installed them on problem jobs where poor piping practices where used and they will correct that problem in most cases.

    I am not concerned with what a product cost. If its good for my customers, its good for me !

    After the 11% of air is removed from the system what happens ? Dos'nt nature dislike imbalance ? Wont the system try to find air some where and go back ot its original 11% ? Sometime to much of a good thing is just that .

    Scott
  • Al Letellier
    Al Letellier Member Posts: 781
    air scoop location

    How about velocity, guys. When pumping away, the air eliminator is at the point of no pressure change, and lowest system velocity. I learned the 18" rule 40 years ago, and I don't remember pumping away any jobs back then. We have hundreds of boilers with standard air eliminators 6" away from that first 90, and we're NEVER had to go back for an air problem....when pumping away!

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