Magnetic filter on a steam boiler water heater?

NJ08534

Hi guys, I’m sure this question has been asked many times, however I found it difficult to find in my search patterns for the strictly steam wall…

I have a well running steam boiler that uses a (stainless, not bronze unfortunately) taco pump and aquastat to circulate hot boiler water through an indirect Amtrol hot water tank.

There is no y strainer in line currently to the tank. I was thinking of adding one but the thought maybe one of those Calffi magnetic strainers folks use on hydronic systems might be a better choice (maybe with a convenient valves bypass plumbed in as well in case of unhappy clogs).

What is the proffered thought out there?
Wye-strainer, magnetic filter, or just keep nothing there?

If so, adding to the Supply side or return side… any preference?

-p

Example mag filter:
https://www.supplyhouse.com/Caleffi-NA545396-1-DIRTMAG-Dirt-Separator-with-Magnet-Union-Sweat

Example y strainer:
https://www.supplyhouse.com/Macon-Balancing-MBP-SV-075F075F-3-4-FNPT-SV-Combination-Ball-Valve-Wye-Strainer-and-Union-w-1-2-Bypass-Port?gclid=Cj0KCQiAraSPBhDuARIsAM3Js4rYn6K-BKxgndvUPUpEKmnhwoed5u34dekGV6SmiPWuwuj89bPY9rEaAgRwEALw_wcB

Jamie Hall

Magnetic filters are great for one specific class of contaminants: iron oxides in the form of magnetite. This is a black mineral, usually in very fine particles. I wouldn't be a bit surprised if there were some. Regular filters/strainers don't get rid of this very well as it's too fine. On the other hand, regular filters do get rid of a range of other, slightly coarser materials and sediment which the magnetic filters don't touch. Both will do no harm.

JUGHNE

That is rated for 195 degree max.
If pumping lower steam boiler water thru it, would that be pushing the max limit?

Daveinscranton

Curiously, I am dealing with filtering today.  I have radiant hydronic pex in slab heat.  Historically I have used a whole house water filter once a year or so to filter my water.  Or after any piping alterations.

I bought a 1-1/4 NPT Caleffi Dirt Mag Pro which will go in (once the cold weather is over) on the secondary loop (primary/secondary piping).  Seems nicely made.  2 sets of magnets.  One set in a well in the center and another set on the brass body.

I got to thinking about a second one in the primary loop.  I observed a lot of turbulence in the clear plastic whole house set up.  Temporary garden hose type of set up that I attach once a year.  Maybe 5” in diameter and 10 inches deep.  So.  The current plan, based on using up odds and ends here is to make one.  1-1/4 by 1-1/4 by 2” bull headed (copper) tee with a 2 foot copper down section sweated on the 2” bull.  I am going to put 18” of 1/2” copper tubing in a hole drilled from the top to make a dry well. And fill it with magnets.  More magnets on the outside of the 2” by 2 foot copper section at the bottom.  There will be a baffle in the bull to direct incoming water downwards.  2” to 3/4” reducer at the bottom and a 3/4” ball valve.  The way I am attaching the 1/2” well is by using a 1/2 by 3/4 by 3/4 tee at the top.  This will give me a place to bleed air and to add a quart of inhibitor (in the 3/4” branch).  My thought is that 2 feet should help particles settle out.  A bigger bull would help.  But I didn’t have one.

Should know the results in a year.  I did look up magnetic permeability of brass vs copper.  Essentially no difference.  

Best wishes 

Daveinscranton

I believe that the filter should go ahead of the pump.  A cartridge pump would otherwise be a magnetic filter.  Which you would like to avoid.

If it was a bronze Bell and Gossett 100 or similar pump, not a worry.

SteamingatMohawk

@Daveinscranton Please be more specific as to "ahead of the pump" , it should be on the discharge (also, called the outlet) side for those not familiar with pumped piping systems.

Derheatmeister

SteamingatMohawk said:

@Daveinscranton Please be more specific as to "ahead of the pump" , it should be on the discharge (also, called the outlet) side for those not familiar with pumped piping systems.

IMO ...I think he is saying that the Magnetic Filter setup should be Prior to the Wet rotor circulating pump(Suction side) in order to avoid the Magnetite from being attracted to the Magnetic field of the Circ....Magetite does cause issues with wet rotor circs..
He is also saying that he is not worried with "Pumps" that do not have the Magnetic field such as the BG 100 series Circulating Pumps

I agree with is..

Erwin

Well I just registered for this forum. Basically I would like to know if magnetic filters are advisable for our closed loop hydronic system that already has a 10 micron string filter on a side stream that flows 5 to 6 gpm. Neodymium magnets inside the string filter attracted zero visible magnetite. Thanks and my apologies if this question is too simple for this forum.

Mad Dog_2

If this isn't some kind of Laboratory experiment, I think your fine with what you have.  They are a great novelty and very cool, but if you have a Cast Iron or Steel boiler and Baseboard or convectors, they could be overkill. Spend that $ on a good German  beer 🍺 or new Strings for your bass!!   Mad Dog 🐕 

gerry gill

Use a wye strainer unless the temperature rating of the magnetic strainer housing can handle it.