Jacobus steam radiator vents - what gives?

Precaud

I would like to experiment with different radiator venting combinations, and the most convenient and cost-effective way to do it is with Maid-O-Mist vents.

I have read some pro installers steer users away from the MOM vents, due to their apparently using plastic floats internally.

When I use google to search for posts on these vents, I see many satisfied users and no evidence of them failing due to the plastic floats.

So what's the story here? Is the plastics objection just a theoretical one? Or is there any evidence to back it up?

ChrisJ

It's pretty much like everything else in life.

Opinions.

You know what they say about opinions right?

I've never used a MOM vent but avoided them because of the plastic.

SteamingatMohawk

Is this an engineering experiment or something more mundane like balancing a system in a building you own?

I spent a lot of time on my converted 2 family near Schenectady, NY, going from Heat Timer Varivalves through MoM valves with lots of orifices to mainly Vent Rites. I have a table and chart I created based on a report on vent valve capacities that may help you, if you are interested.

Hap_Hazzard

I've never seen evidence, but I've heard people claim they have. All I can tell you is that I've been using them on all of my nine radiators for more than ten years, and in all that time I've only had one bad one. I took it apart to try to see why it failed, but I couldn't see anything obvious, so I don't know if it's the plastic float or the brass seat.

Someone claimed he's seen them leaking around the seal between the front and the back, which I find a little hard to believe having taken one apart, but then, he also claimed that they're made in China, whereas mine all say "Chicago" on them, for what it's worth.

Ironically, I bought these vents assuming they probably wouldn't last. My original plan was to use them to get my radiators balanced and then replace them with Gortons whenever they failed because they use the same sizing system, but then, as I said, I've only had one fail, and I'd bought a few extra because they're cheap, so I haven't had to spring for Gortons yet, except for the ones I got for my mains.

Precaud

SteamingatMohawk said:

Is this an engineering experiment or something more mundane like balancing a system in a building you own?

The latter.

Because of a flaw in the NBP, there's nothing much I can do with main venting until the piping is correected. Because of that, chances are it isn't going to behave "by the book" so I'll experiment with the rad venting. But sure, I'd like to see your report.

Yes, lots of opinions... I'm wanting to see if there is anything credible behind the negative ones, of greater incidence than other rad vents.

Precaud

Hap_Hazzard said:

All I can tell you is that I've been using them on all of my nine radiators for more than ten years, and in all that time I've only had one bad one. I took it apart to try to see why it failed, but I couldn't see anything obvious, so I don't know if it's the plastic float or the brass seat.

I like those percentages... thanks for weighing in.

nicholas bonham-carter

Precaud as the main vents do all the heavy work of air elimination in the supplies, it would be beneficial for you to put generous main venting on now, even if they have to be moved/reinstalled when your repiping starts.
More venting equals shorter run times, and smaller fuel bills.—NBC

Precaud

@nicholas bonham-carter , thanks but that's not true in this case.

See: https://forum.heatinghelp.com/discussion/178437/old-bryant-steam-boiler-and-duty-cycle#latest
where you basically said the same thing but were told why it doesn't apply in this situation... not yet, anyway. I am going to experiment with the main vent but am not expecting any significant change from it.

And its not the subject of this thread.

ethicalpaul

I have exclusively MoM after experimenting with some others which were more noisy (metallic ping on close/open) or had adjustment problems (for the ones I tried that were adjustable).

The MoM are chromed brass. They even have a #1 main vent that I'm going to try. Which came first? Jacobus or Gorton? I have to find out some time.

You want the real Jacobus ones from Chicago, not the no-name ripoffs currently available in Home Depot. I had one of the no-names with a bad stamp seal that would spin.

I get mine for a single digit dollar value from supplyhouse. This link should give credit for your visit to heating help: https://www.supplyhouse.com/Jacobus?utm_source=HeatingHelp

mattmia2

If you could find a place to add a main vent or 2 at the far end of your mains that would help your balancing task greatly, if there is some fitting or stub you could take out and add a tee or vent to the main far from the boiler.

Precaud

It's an interesting suggestion, @mattmia2 , one I'll pursue in the other thread. Got any experience with MOM air vents?

Precaud

Bump to get input from more folks.

So far, we have direct evidence of one vent failing. I watched a youtube last night (made by a Heatinghelp member, I believe) which showed a cutaway comparison of a MoM and a Gorton. While he objected to the plastic float, he noted no failures due to it. His main objection was that the case parts were only crimped together, and not sealed/soldered like the Gorton's.

ethicalpaul said:

I have exclusively MoM after experimenting with some others which were more noisy (metallic ping on close/open) or had adjustment problems (for the ones I tried that were adjustable).

Nice.

The MoM are chromed brass. They even have a #1 main vent that I'm going to try.

I wish I'd known that before ordering the Gorton #1, I would have tried one.

You want the real Jacobus ones from Chicago, not the no-name ripoffs currently available in Home Depot.
I get mine for a single digit dollar value from supplyhouse. This link should give credit for your visit to heating help: https://www.supplyhouse.com/Jacobus?utm_source=HeatingHelp

Yes, that's where I ordered a couple from, along with other stuff. Their service is excellent; everything shipped same-day. Should be here Monday.

Apparently Jacobus used to sell a version of the rad vents that came with a full set of the screw-in orifices. Would have been nice to have one of those for experimenting.

ethicalpaul

I think they still sell that. But honestly, the individual vents are so cheap that you can order a few different sizes and swap the orifices as needed anyway.

I defy anyone to look at a real MoM and tell me the seal in the body isn't up to snuff. I have an old no-name one that was loose, but my real MoM are rock-solid.

Hap_Hazzard

The MoM vent I took apart had a neoprene gasket between the case halves, which seems to make at least as good a seal as a bead of solder. The brass is very thick too. It took a lot of effort to un-crimp it.

SteamingatMohawk

Here's my table and chart. The bottom line in it is for the really low end (less venting than a #4), you need an adjustable vent, like the Vent Rite.

For lots of radiator venting, the Varivalve has a lot more capacity, but on the low end, it still passes a #5 capacity when set at minimum/shut.

I highlighted the Varivalve numbers to make it easier to see. The data is from the Gill/Pajek report in 2005.

SteamingatMohawk

Here's the copy with the highlighting and mention of the report.

Hap_Hazzard

I notice there's no sample size, mean or standard deviation, which makes me suspect they're all based on a sample size of one, which should be taken into consideration, especially wrt the variable vents.

I've noticed a lot of variation in the actual port sizes of the MoM vents caused by deformation caused by the number or letter being stamped too close to the hole. It's probably not all that significant, and it could even be useful in those cases where you might want something with a slightly smaller port, but I admit it's not very scientific.

Gordo

My main objection to the MoM vents is when they fail and sometimes when you go to remove them, the crimped gasket has allowed the body to spin, while the threaded part remains in the radiator.

The Gortons do not have that switchable orifice, that is true and they cost more. However, when you compare them side by side in the hand, the Gortons are clearly better built both inside and outside and are likely to provide better longevity.

For a homeowner, the MoM might be the better deal. As a steam professional who wants to avoid call-backs, I'll avoid the MoM.

Hap_Hazzard

@Gordo, are you saying that the fitting comes out of the body, or the front of the body separates from the back?

motoguy128

I have all MoM on my TRVs. Everything else has ventrites. But my boiler is intentionally undersized to the radiator capacity, so only 5 of the 15 regularly see steam.

When I was experimenting with balancing and vent rates last winter , I emailed MoM and they sent me a bag with about 30 orifices. I’ve since used up all the 4s. They also sent me a drill size chart for the holes. Basically any 4 can become a 5,6,C or D. You can even make a 4.5, 5.5 etc as I think there are intermediate drill sizes.

Gordo

@Hap_Hazzard : What happens is...oooh, the next time I get one, it is so going on YouTube!...is the main body, the part with the vent, when you grip it to spin it off and expect the whole valve to spin out of the 1/8" npt hole like it should, is the that body slips around the "crimp", while the back part with the 1/8" npt stub Does. Not. Move. The only way to get that PoS MoM out is to get a very small Knipex pliers and get a grip on that 1/8" bugger and eventually spin it out. Such fun.
You start to look at a MoM vent in a whole new light when that happens!

STEAM DOCTOR

@Gordo. Same thing has happened to me endless times. What I do is wiggle the vent body back and forth until it separates from the nipple. Then easy pickings to get nipple out

Hap_Hazzard

I honestly can’t see that happening. I’m gonna have to see it to believe it. That brass is really thick.

Gordo

Its not the brass that fails, it slides around and around in the crimped part!!!
@STEAM DOCTOR : Thanks for the tip!

BobC

@motoguy128 Could you post that MOM drill size info?

Bob

ChrisJ

Hap_Hazzard said:

I honestly can’t see that happening. I’m gonna have to see it to believe it. That brass is really thick.

How can you not see that happening?

ethicalpaul

ChrisJ said:

Hap_Hazzard said:

I honestly can’t see that happening. I’m gonna have to see it to believe it. That brass is really thick.

How can you not see that happening?

Have you held one on your hand? The no-name junk copies, sure, but real MoM are solid.

Hap_Hazzard

ChrisJ said:

Hap_Hazzard said:

I honestly can’t see that happening. I’m gonna have to see it to believe it. That brass is really thick.

How can you not see that happening?

Because I've taken one apart. I've seen how they're made. They're thick, heavy brass, crimped very tightly, with a neoprene gasket. Neoprene is not a slippery material.

It sounds like we're talking about two different products here.

Precaud

Hap_Hazzard said:

It sounds like we're talking about two different products here.

Agree, and that's exactly why I started this thread.

Do the fakes look exactly like the originals?

Hap_Hazzard

I've never seen the fakes, so I can't say, but @ethicalpaul says he's seen them at Home Depot. Some of mine came from Home Depot, but that was more than ten years ago, so maybe they're selling knock-offs now. Apparently they don't even say "Maid O' Mist" on them.

Some of the people who've complained about them have said they were made in China. Mine all say Chicago. Maybe they've outsourced some of their manufacturing (like almost everybody else these days) and the Chinese ones aren't being held to the same standards. If that's the case, I think they should know about it.

Recently there's been a spate of defective Barnes and Jones Big Mouth vent discs. The people who found them contacted Barnes and Jones about them and got replacements, so, presumably, they're aware of the issue and are working to fix the problem. But has anybody thought to tell Jacobus when they're found defective Maid O' Mist vents? No. From what I've seen they just go around tellng people they're junk and not to buy them and pay three times more for Gorton vents. I'm sorry, but I don't think that's fair.

I think we'd be doing consumers a favor if we could identify the bad products, and if Jacobus is selling bad vents, let them know about it and how to identify them. If some of their products don't measure up, I'm sure they'd want to deal with it, because it's hurting their brand. If it's just a case of Home Depot selling knock-offs, I think both Jacobus and Home Depot should know about it, because it's hurting both of them.

ChrisJ

@ethicalpaul @Hap_Hazzard

What I got from Gordo was the 1/8" NPT nipple starts spinning in the back of the housing. Is there neoprene there?

I could easily see this happening on many things. Brass is soft and crimped won't hold terribly well on something of such a small diameter.

Hap_Hazzard

The ⅛" fitting is actually soldered in, at least in the one I took apart, but from what Gordo said,

Gordo said:

Its not the brass that fails, it slides around and around in the crimped part!!!

it sounds like he's saying the whole back is sliding around.

Precaud

If the crimping is loose, that's a pretty easy fix with pliers...

Hap_Hazzard

I wouldn't try it. I'd send it right back to Jacobus and say, "what's the deal???" Or, as Mike would say,

ethicalpaul

I don't think you'd want to bother to fix a seven dollar vent with pliers. I am quite sure the patent on this vent has expired, so anyone can make this design without ramification (in fact, I'm sure Gorton or Jacobus must have copied the other decades ago).

I'm not saying it's impossible to have a MoM vent spin on a failed crimped back. Let's say it happened. How many years old was it, and how tightly must it have been in that port?

It's fine for folks to choose not to use them. All I'm saying is that before spreading negative opinions about them, hold one in your hand, put it on a radiator, and see how it works. I'm convinced it's the best value in radiator vents available.

ethicalpaul

Precaud said:

Hap_Hazzard said:

It sounds like we're talking about two different products here.

Agree, and that's exactly why I started this thread.

Do the fakes look exactly like the originals?

Well, very similar. I wouldn't call them fakes (I'm not sure if I did in the past). I would call them "knockoffs" or "a very similar design made by a different company"). They weren't marked "Maid o' Mist"--they just looked identical from a distance.

Chris_L

The picture @Precaud posted is of a real one.

The ones I saw at my local Home Depot had no markings on them at all. And I could not find a country of manufacture on the plastic bag the vent was packaged in.

I think Home Depot is scamming people. If you go to their website it says the ones they are selling, including those at my local store, are Maid O'Mists made in the USA. In reality, all the ones at my local store were no-name generics made who-knows-where.

As for them coming apart, I'd be interested to hear what those who've experienced that are using on the threads. And just how tight are you tightening them? I have never had a problem with them using teflon tape.

Hap_Hazzard

ethicalpaul said:

I'm not saying it's impossible to have a MoM vent spin on a failed crimped back.

I'm just having a hard time seeing it, because the machines that perform that operation produce very consistent results. Assuring the quality of solder joints is a much harder proposition.

gfrbrookline

@Hap_Hazzard has a valid point, I have had a Big Mouth, Gorton and MOM fail. I contacted Barnes and Jones and Gorton for replacements and both companies stood by their product and sent replacements. I did not do so with the MOM because of the price point and was suspect of the plastic bladder and crimping.

Bottom line they are all decent products, maybe not the HD knockoffs, that do the job. Just like cars, you can buy a Ford or a Rolls Royce, at the end of the day it gets you from point A to B, it just depends on how much you want to pay for the craftsmanship and materials that go into the product. I prefer welds over crimps and brass over plastic, will it last longer, who knows.

ChrisJ

Since we discussing quality.

I've never known @Gordo to be full of s........beans.
The quality of his word tends to be high.

Just saying.

ethicalpaul

ChrisJ said:

Since we discussing quality.

I've never known @Gordo to be full of s........beans.
The quality of his word tends to be high.

Just saying.

I agree completely and having had the pleasure of meeting him, that was only reinforced.