Gauge glass erosion

ChrisJ

My gauge glass has been seeping for a few years now and I knew I needed to fix it but I had no idea it was going to be this bad.

I knew my pH was on the high side but I always felt I'd rather replace a cheap glass than a boiler.

Here's what I found after 9 years of 2 tablets of Steamaster.





Yes it's chipped at the bottom, and I scored it a hair in the middle expecting to have to break it in half to get it out.  The chip isn't from me and not only did I not have to break it to get it out but it was much shorter than it was new.  The funnel shape you see at the middle isn't an illusion, it's there.

Original length was 7 3/8.  It's now 7 3/16 and razor thin on the bottom half.

I think from now on I'll put a new glass in every 5 years or so.

EBEBRATT-Ed

I only ran into this once. We had a high pressure steam process boiler that we couldn't keep gauge glasses in the thing without leaking. They wouldn't last even a month. Etche's the glass

Finally had the water tested and got a water treatment guy on site

ChrisJ

EBEBRATT-Ed said:

I only ran into this once. We had a high pressure steam process boiler that we couldn't keep gauge glasses in the thing without leaking. They wouldn't last even a month. Etche's the glass Finally had the water tested and got a water treatment guy on site

I assume how high the pH is Temperature etc effect the speed of it.

My pH runs between 9 and 10 I think.  9 years is good enough for me but 5 is safer I think.

dopey27177

In a home sized boiler operating at 2 psi and less the gauge should last forever. looking at the gauge glass it appears to have been leaking for a long time look at the rusty color and how it traveled up to the packing nut.

For many years now the packing rings supplied were made of rubber or synthetic rubber, they get hard and crack then leak slightly. the glass is hot enough to vaporize the slight water leak.

When you replace the gauge glass install graphite packing instead of the supplied packing ring. That done you will never see that rust color again on the gauge glass.

Jake

ChrisJ

dopey27177 said:

In a home sized boiler operating at 2 psi and less the gauge should last forever. looking at the gauge glass it appears to have been leaking for a long time look at the rusty color and how it traveled up to the packing nut. For many years now the packing rings supplied were made of rubber or synthetic rubber, they get hard and crack then leak slightly. the glass is hot enough to vaporize the slight water leak. When you replace the gauge glass install graphite packing instead of the supplied packing ring. That done you will never see that rust color again on the gauge glass. Jake

Jake,

I feel you missed the entire point of the post.

  

The outside of the glass is fine and the rubber was fine.   Yes it was leaking but I didn't realize the lower half of the glass was paper thin until I removed it today.

The inside was eroded.

ChrisJ

@Hap_Hazzard
@Gordo

JUGHNE

I don't know what your last post refers to, but Gordo has a recent Utube on the very subject caused by the same high PH.

ChrisJ

JUGHNE said:

I don't know what your last post refers to, but Gordo has a recent Utube on the very subject caused by the same high PH.

Gordo had commented on a thread on the subject many years ago.

I didn't know about the YouTube video?

JUGHNE

I watched it maybe a week ago, don't think the video was very old.

I wish he made more of them.

ChrisJ

Here's the video

https://youtu.be/uY0MZ7p08F0

Mine doesn't have any damage or erosion to the upper half as my water level is fairly stable.

PMJ

@ChrisJ ,

I happened across this. Seemed to address exactly what you were talking about but I have no idea if it makes any sense or not. I'm at 30 years on both my untreated boiler at home and heavily treated 200HP firetube at work and never had to replace a sight glass.

https://watersystemsmanagement.com/2020/06/08/boiler-sight-glass-erosion/

ChrisJ

PMJ said:

@ChrisJ , I happened across this. Seemed to address exactly what you were talking about but I have no idea if it makes any sense or not. I'm at 30 years on both my untreated boiler at home and heavily treated 200HP firetube at work and never had to replace a sight glass. https://watersystemsmanagement.com/2020/06/08/boiler-sight-glass-erosion/

There's no condensation running down the glass.  There's no erosion on the top half of the glass at all.

Its from high pH and it's staying that way.

   

Thankyou for sharing it though, the more info the better imo.

I think Gordos video is excellent.

HVACNUT

If the pH is going to stay that way, how about a high pressure gauge glass?

ChrisJ

HVACNUT said:

If the pH is going to stay that way, how about a high pressure gauge glass?

The one I installed is rated for 280 PSI steam.

The previous one went through 9 seasons.....

Jamie Hall

I hadn't been paying much attention to this one... just a minor comment. It's worth remembering that water -- good old water -- is about the closest thing to a universal solvent we have. But it won't attack glass unless the pH is quite basic -- 9 or above. If it is basic, though, at that level, it will dissolve glass. Why I recommend -- if asked -- that if it needs to be controlled boiler water pH should not be higher than 8.

KC_Jones

Jamie Hall said:

I hadn't been paying much attention to this one... just a minor comment. It's worth remembering that water -- good old water -- is about the closest thing to a universal solvent we have. But it won't attack glass unless the pH is quite basic -- 9 or above. If it is basic, though, at that level, it will dissolve glass. Why I recommend -- if asked -- that if it needs to be controlled boiler water pH should not be higher than 8.

Won't argue any of your statements about what is going on chemically, totally accurate.

For @ChrisJ and I, we'd rather run the PH high to the point of eroding glass, than replace the entire boiler. Glass is cheap, the iron, and associated labor, not so much.

Last time I checked PH, mine was sitting around 10.

Life is filled with choices.

ChrisJ

Jamie Hall said:

I hadn't been paying much attention to this one... just a minor comment. It's worth remembering that water -- good old water -- is about the closest thing to a universal solvent we have. But it won't attack glass unless the pH is quite basic -- 9 or above. If it is basic, though, at that level, it will dissolve glass. Why I recommend -- if asked -- that if it needs to be controlled boiler water pH should not be higher than 8.

But at the same time as you become more acidic it dissolves cast iron which is why I recommend staying in the 9-10 range.

A $15 gauge glass every 5+ years isn't worth a new boiler.

It is fascinating that what attacks one material is safe for another.

PMJ

One more opinion attached - this from the ChemWorld site.

I am sure my PH in the treated boiler is over 9. Never replaced the glass.

I admit I don't know what is happening.

ChrisJ

PMJ said:

One more opinion attached - this from the ChemWorld site.

I am sure my PH in the treated boiler is over 9. Never replaced the glass.

I admit I don't know what is happening.

If your pH is above 9, perhaps you want to drain that glass and look at it closely.

ethicalpaul

I just set an alarm for 2030. No way I'm giving up my 10-11 ph

EBEBRATT-Ed

@HVACNUT

Tried HP gauge glass it didn't make much difference

PMJ

ChrisJ said:

PMJ said:

One more opinion attached - this from the ChemWorld site.

I am sure my PH in the treated boiler is over 9. Never replaced the glass.

I admit I don't know what is happening.

If your pH is above 9, perhaps you want to drain that glass and look at it closely.

I keep spare glass material and gaskets on hand always. At a minimum, after 30+ years of operation we can conclude I don't have the issue you do, whatever is causing it. At the rate of deterioration you are describing mine would have failed long ago. It is starting to appear that perhaps it is not just the PH, but maybe due to a specific ingredient in the treatment.

For all I know the glass in the boiler at home is original. I can account for 30 years of the 65 anyway. I do no treatment in that one like the manual advises.

ChrisJ

Not treating the water in any steam boiler is fascinating.

I mean besides all of the modern ones rotting out, the other fact is all of the mineral and scale that builds up over time without treatment.

PMJ

ChrisJ said:

Not treating the water in any steam boiler is fascinating.

I mean besides all of the modern ones rotting out, the other fact is all of the mineral and scale that builds up over time without treatment.

There is only so much scale introduced when you don't change or add water. I only make sure the bottom drains actually run each season and I operate the LWCO every couple weeks. Can't be 5 gallons a year added - likely half that. So I just run the same water now boiled 10s of thousands of times. I don't know where idea came from that these things turn naturally acidic. Obviously mine doesn't.

My vacuum system is open to the atmosphere less than 10% of the total elapsed time so I have minimal new air also.

ethicalpaul

This is interesting: https://www.corrosion-doctors.org/Household/Glass.htm

The second stage of corrosion is a process of destruction of the leached surface layers of glass. Glass is resistant to most acids but is highly susceptible to attack by alkaline materials, especially a concentration of OH- ions giving a pH greater than 9.0. The result is an attack of the network forming silica-oxygen (Si-O) bonds, leading to dissolution of the glass surface.

nde

Had not idea but did see that GS video lately... like that one write up says you dont want to be around if/when it explodes!

ethicalpaul

It won't explode, not at our pressures. It will start to ooze.

Hap_Hazzard

The thing that looks really weird to me is how uniform the erosion is. Mine gets ripples where it's been eroded.

Maybe you should remember to invert the glass every season so you get more use out of it, unless you drop it on the floor while you're taking it out.

ChrisJ

Hap_Hazzard said:

The thing that looks really weird to me is how uniform the erosion is. Mine gets ripples where it's been eroded. Maybe you should remember to invert the glass every season so you get more use out of it, unless you drop it on the floor while you're taking it out.

I manually feed and keep it within a 1/2" of it's proper height.

I had thought about flipping it.  

Hap_Hazzard

ChrisJ said:

I manually feed and keep it within a 1/2" of it's proper height.

Same here. The ripples aren't due to a fluctuating water level. It's just a wavy appearance like frost on a window.