Don't Forget Them Strainers

[Tennman]

Thot I had a bad pump. But noticed a BIG temp drop across a strainer. First time I've seen one apart. Never checked in 8 years. Plugged up with black goop probably from the anti-corrosion chemicals... what else could it be in the water????

Anyway.... little stuff you just ignore until stuff stops. I need to start a Post Season Inspection List.

Happy New Year.

 

[Bob Rohr]

A dirt separator is a better device for hydronics. It doesn't trap the particles in the fluid stream like Y strainers. Be sure you mesh size is correct also, if you use Y strainers..

This MetraFlex Y strainer is a bit more evolved, but only available in large sizes.

In some cases Y strains are only used as a start up device, remove the strainer after a few weeks if the system is clean and can stay clean, no O2 ingress for example.

http://www.metraflex.com/strainers-and-suction-diffusers/lpd-y-strainer/

 

[goosegunner]

A dirt separator is a better device for hydronics. It doesn't trap the particles in the fluid stream like Y strainers. Be sure you mesh size is correct also, if you use Y strainers..

This MetraFlex Y strainer is a bit more evolved, but only available in large sizes.

In some cases Y strains are only used as a start up device, remove the strainer after a few weeks if the system is clean and can stay clean, no O2 ingress for example.

http://www.metraflex.com/strainers-and-suction-diffusers/lpd-y-strainer/

Bob,

How do dirt separators compare to Hot water filters? A guy I know that is putting in a Portage and Main outdoor unit said the factory suggests a Hot water filter with a bypass set up. I suggested a dirt trap. He asked Portage and Main and they told him they only catch big particles?

They told him to use the valve to get a 60/40 split in flow through the filter. I asked how would you know the flow? Portage and Main told him to choke the valve down until you hear the pump struggle and back off a hair....

 

[Bob Rohr]

I'm not sure what a hot water filter is? Most of the mesh or cotton will take particles down to a certain size based on the mesh or material inside.
I'd like to see all the fluid go through the device every trip. Else a particle can go around the bypass filter loop and damage a pump, valve, etc, from my perspective?

A separator uses a coarse screen and centrifugal force to drive particles out of solution. With a separator the dirt and debris is forced down to the space below the media inside, so no flow reduction.

Ideally I'd keep up on the water treatment and not need to deal with corrosion, sludge, and rusting metal particles. Then a filter or separator becomes a secondary insurance.

I know with open systems that takes some commitment and $$ to maintain fluid quality.

 

[Tennman]

Thanks Bob. I think Y’s were the norm back almost 10 years ago in all the schematics I saw. Will look at the separator. We had to go on propane while I fixed stuff and the wife said “when’s the boiler gonna be back up, it’s warmer!”. Spent all day yesterday swapping a Chinese ball valve that split! I try to avoid all Chinese junk, but just can’t.

Cheers to all.

 

[dogwood]

Be sure you mesh size is correct also.

Bob, how do you determine the correct mesh size? I've got a couple Jomar T-100FB's ( ball valves with integral filter screens), you recommended here a while back. I've wondered if the mesh size in them was correct. They can utlilze 20, 40, 60, 80, and 100 mesh sizes. I believe mine came with the standard 20 mesh.

They seem to work well and collected a fair amount of goo by the end both the first and second burning season. Hopefully the screens will be clear when checked after this winter heating season's over.

I try to avoid all Chinese junk, but just can’t.

Couldn't agree more Tennman. The few Chinese plumbing parts I've used have given me fits, like I'm sure you experienced with your split valve, I was in your home state twice recently to purchase some vintage American wood-working machines (a 1944 Delta lathe and 1973 Delta planer). I wouldn't have the equivalent brand new Chinese made machines in the house. It seems there is no quality control at all in their manufacturing of anything, not just plumbing parts. Take it easy.

Mike

 

[Bob Rohr]

I have always heard that 20 - 40 mesh for hydronics.. Steam guys with cast iron rads seen to lean towards the coarser mesh sizes.

I think the key is to service them yearly. If after a year or so the strainer is clean, your system is probably scrubbed of crud.

I used the Jomar filter balls for a few years, the mesh is fairly fine, and the small size doesn't take much to plug.

 

[Karl_northwind]

Just cleaned a bunch of crud out of one today. I'm glad the installer put a strainer in. I was expecting to have to swap out the HX.

 

[warno]

So should a strainer be clean at least once a year at start up? What about mid heating season? Asking about a open and closed system.

 

[velvetfoot]

Is that black stuff manganese?

 

[nhtreehouse]

How many people think magnetic separation is a good idea? I ask because I put together this radiator hose clamp and rare earth magnets solution for my spirotrap. I would have used a Caleffi dirtmag unit but space was tight and they take up more room on the run. I doubt this is as good as a commercially available solution, but here it is:

 

[Bob Rohr]

magnetic seperation is critical if you have, or will add, ECM type circulators, I feel. The powerful magnets inside the ECM wet rotor circulators can attract small ferrous particles. It is a cheap insurance policy to keep from seizing a circ.

The fine black particles may be magnetite which forms when O2 enters a system and breaks down the ferrous metals. It looks and feels like a black inky fluid, when it drys you will see the particles. If the particles stick to a magnet you have magnetite or hematite deposits in the system.

 

[dogwood]

So should a strainer be clean at least once a year at start up? What about mid heating season? Asking about a open and closed system.

That's what I've done Warno. Once right after startup and once again at the end of each heating system. I can't remember how I got on that schedule. Might have been something I read on site. I would think common sense might be your guide. If you're picking up enough junk that its impeding your flow like Tennman had an issue with, maybe you''d need to clean them more frequently. At some point all the junk should be cleaned out of your system and it should run clear. In my case I probably used too much Rectorseal on my black iron pipe joints on installation and that ends up gumming up the strainer's screens. No leaks however, so a decent trade-off. Maybe they'll be clean this time around

Mike

 

[warno]

@dogwood I'll keep that in mind each season. Mine have been in for 2 seasons with no maintenance. I'll definitely be cleaning them during my replumb this summer and keeping a closer eye on them.

 

[Tennman]

Is that black stuff manganese?

Don't know but it flushed off the stainless screen cylinder easy. It wasn't gritty like a metallic would be. Ya think I should check it more than once every 10 years?

 

[Tennman]

Oh... the other thing I was wondering since performance dropped off was the temp readings out and return to the boiler barn. I was seeing far more than the design 30*F out/in temp drop. So..... first thot was OH CRAP.... underground problem! AAAGH!

Nope, just BTUs/hr sucked due to the clog. But the symptoms were the same. Anyway, after clearing screen, BTUs/hr restored, deltaT in/out of the boiler barn returned. Until.... my next thread.