Added my low pressure gauge

Don_175

So I added my low pressure gauge today. It wasn’t difficult. 

I had skimmed my boiler several times over the last few weeks. I still get fluctuations/bouncing in the water level of about 1.5” but it no longer drops to the bottom. 

I started boiler. Pressuretrol is set for CI 0.5 and differential of 1. 

The gauge relatively quickly goes to 0.5 psi and after several minutes of steaming, it sits at about 0.8 psi. The needle fluctuates at most between 0.75 and 0.85. Does all that sound reasonable? I assume some needle vibration is normal. Thanks for all your advice. 

Hap_Hazzard

That's similar to what I see. Mine never goes above 0.5 psi, but I believe this difference probably means my radiation is a little more closely matched to the boiler's output. Ideally the radiators should condense the steam as fast as the boiler produces it, but as long as we stay under 1.5 psi, and not cycling on pressure, I'd say we're doing pretty well.

The fluctuations are normal, since steam is produced in bubbles, but, like the fluctuating level in the gauge glass, less is better. Flushing and skimming the boiler can reduce it, but you can never eliminate it.

Don_175

Thank you. I went back and looked again. Today, when it starts producing steam, it is  basically ticking between 0.5 and 0.6. And after running for 10 minutes, it hovers around 0.7. 

ethicalpaul

Does it go to .5 psi even before the main vent is closed? If so I'd say more main venting is called for.

Don_175

ethicalpaul said:

Does it go to .5 psi even before the main vent is closed? If so I'd say more main venting is called for.

I'm not sure. How would I tell? Feel pipe where vent is to see when it gets hot?

EBEBRATT-Ed

@Don_175

The gauge needle pulsing is normal. But low pressure gauges don't survive that very well. I would put a valve or gauge cock under the gauge and keep it shut unless your checking the pressure.

ChrisJ

Here's my Magnehelic without a snubber, or a valve.

https://youtu.be/Sndnc4ZFFVs


That went on for a few weeks and then I added a 0.015" snubber from Mcmaster.

The snubber is just a fitting with a 0.015" hole in it so it restricts the flow. For those who are afraid of the gauge breaking and venting steam into the room the snubber also restricts that as well.

ethicalpaul

Don_175 said:

ethicalpaul said:

Does it go to .5 psi even before the main vent is closed? If so I'd say more main venting is called for.

I'm not sure. How would I tell? Feel pipe where vent is to see when it gets hot?

You can do that, or you can feel or hear the air escaping the main vent before it closes.

reggi

@ChrisJ

The snubber is just a fitting with a 0.015" hole in it so it restricts the flow. For those who are afraid of the gauge breaking and venting steam into the room the snubber also restricts that as well

Well it's good that you take some precautions against failure of constant operation of a ultra low pressure gauge on your quasi vapor system..
Is that the gauge without a siphon on a 18" 1/2" pipe attached to your boiler ? A photo would be interesting 

archibald tuttle

@ChrisJ that is only a 2 inches of water gauge?

ChrisJ

archibald tuttle said:

@ChrisJ that is only a 2 inches of water gauge?

Yes sir 

reggi said:

@ChrisJ

The snubber is just a fitting with a 0.015" hole in it so it restricts the flow. For those who are afraid of the gauge breaking and venting steam into the room the snubber also restricts that as well

Well it's good that you take some precautions against failure of constant operation of a ultra low pressure gauge on your quasi vapor system..
Is that the gauge without a siphon on a 18" 1/2" pipe attached to your boiler ? A photo would be interesting 

I'm curious why you keep bringing this up?
Do you feel there's a safety issue with it?

reggi

reggi said:

@ChrisJ

The snubber is just a fitting with a 0.015" hole in it so it restricts the flow. 

Well it's good that you take some precautions against failure of constant operation of a ultra low pressure gauge on your quasi vapor system..
Is that the gauge without a siphon on a 18" 1/2" pipe attached to your boiler ? A photo would be interesting 

I'm curious why you keep bringing this up?
Do you feel there's a safety issue with it?

I apologize sir for the confusion.. 
I'll try to go slow and explain..
I had made my opinion known in a previous post that I am of the opinion that Ultra. low pressure gauges used for fine tuning and other visual pressure movements are of value when they are being observed.
I am of the opinion that being of ultra low pressure that exposure to continuing boiler cycling has more of a wear and tear affect on these type gauges and thus a ruptured or some other type failure risks the release of steam into the boiler room and beyond..
As such most consciencious installations
require a valve installed for good practice..

Though to preciously answer your question
I'm curious why you keep bringing this up?

I'm not..I was responding to your comment:

For those who are afraid of the gauge breaking and venting steam into the room the snubber also restricts that as well

So I really didn't bring it up...you brought it back from the last thread..
We may have varying opinions on certain things..But FACTS are undisputable

Don_175

ChrisJ said:

The snubber is just a fitting with a 0.015" hole in it so it restricts the flow. For those who are afraid of the gauge breaking and venting steam into the room the snubber also restricts that as well.

Is that 0.015" opening specific to the type of low pressure gauge you have? I have a 0-3 psi. Would I use the same opening? I looked on Amazon and there are several but they do not specify internal opening.

ChrisJ

Don_175 said:

The snubber is just a fitting with a 0.015" hole in it so it restricts the flow. For those who are afraid of the gauge breaking and venting steam into the room the snubber also restricts that as well.

Is that 0.015" opening specific to the type of low pressure gauge you have? I have a 0-3 psi. Would I use the same opening? I looked on Amazon and there are several but they do not specify internal opening.

The only place I've seen that actually specifies it is McMaster.  It's not specific, no.  

It just has to do with how fast you want the gauge to respond and I think smaller ones are made for higher pressure.

Don_175

ChrisJ said:

Don_175 said:

ChrisJ said:

The snubber is just a fitting with a 0.015" hole in it so it restricts the flow. For those who are afraid of the gauge breaking and venting steam into the room the snubber also restricts that as well.

Is that 0.015" opening specific to the type of low pressure gauge you have? I have a 0-3 psi. Would I use the same opening? I looked on Amazon and there are several but they do not specify internal opening.

The only place I've seen that actually specifies it is McMaster.  It's not specific, no.  

It just has to do with how fast you want the gauge to respond and I think smaller ones are made for higher pressure.

Thanks Chris. You've been a big help. I see Winters specifies an SSN515 for water but SSN516 for air. Does it really matter which one is used? The 515 seems to be much more available

SteamingatMohawk

@ChrisJ and I have messaged privately over the subject of low pressure gauges not being able to handle a pressure excursion (system failure of some kind). He's having fun with me, which is OK.

If you look at the gauge label it says his Magnehelic is good for 15 psig, which is the Max Allowed Working Pressure (MAWP) for these boilers. I have been looking in codes to see what may be in any regulations.

The ASME boiler code, Section IV, on low pressure heating boilers, is silent, but it is largely focused on the boiler itself for structural integrity.

The NY code considers,

"The term boiler shall include the apparatus used by which heat is generated, and all controls and devices related to such apparatus or to the closed vessel."

I take this to mean any pressure gauge is "required in NY" to be able to operate at that MAWP.

In NY, his gauge is acceptable. I have no idea what, if anything exists in other states.

To me, it seems illogical to not require equipment (controls, gauges, etc.) that can see MAWP not have to handle that pressure. In a stretch of the imagination, it could apply to the radiator vents, but that is a subject for another day I am pursuing out of curiosity when I have nothing else to do.

Bottom line, I have consistently urged guys on HH to either use a Magnehelic (to @ChrisJ's credit) or not leave a low pressure gauge permanently installed or to have an isolation valve specifically for the low pressure gauge.

Send me a message if you want to learn more.

Don_175

ethicalpaul said:

Does it go to .5 psi even before the main vent is closed? If so I'd say more main venting is called for.

So, I checked it out. I have 2 returns each about 35 feet long. Each one has a Big Mouth mid-pipe. When my pipes are warm, but the boiler has been off a while, I timed it. When the boiler started, pressure was at 0. After about a minute, pressure rose to about 0.5 psi and stayed there. I could feel air coming out of Big Mouths. After about 5-6 minutes, the vents closed, and pressure rose to 0.6 psi and leveled off at 0.65-0.7 until boiler shut off. Does this mean I need more venting? Thanks

ethicalpaul

Reading your good description I don’t think so. 

With a big mouth on each main and the gauge only going from .5 while they are open to .6 when they close, I think the gauge probably isn’t accurate but that’s just a guess.

Don_175

ethicalpaul said:

Reading your good description I don’t think so. 

With a big mouth on each main and the gauge only going from .5 while they are open to .6 when they close, I think the gauge probably isn’t accurate but that’s just a guess.

What would you expect to see with an accurate gauge in my situation?

ethicalpaul

I would expect something like .5 to 5 inches of water column with the Big Mouths open. That would be under .2 psi. A Big Mouth provides a LOT of venting.

Now let's say .5 psi were accurate with the Big Mouths open. I can't imagine a scenario where, after they closed, you'd only see an increase to .6 psi

jhewings

I can't comment on the accuracy of the gauge but it sounds like your system is working great. It's spring now so the heat call probably is shorter than it would be in colder weather. Maybe pressure will be higher next winter but if it stays below say 1.7 psi next winter you are in good shape. You mentioned your main vents are "mid-pipe". Are they after the last run-outs?

Don_175

jhewings said:

I can't comment on the accuracy of the gauge but it sounds like your system is working great. It's spring now so the heat call probably is shorter than it would be in colder weather. Maybe pressure will be higher next winter but if it stays below say 1.7 psi next winter you are in good shape. You mentioned your main vents are "mid-pipe". Are they after the last run-outs?

From what I see, they are in the pipes that head back to boiler. There are no branches into these pipes before they drop down to get to boiler

jhewings

OK that's good

Don_175

ethicalpaul said:

I would expect something like .5 to 5 inches of water column with the Big Mouths open. That would be under .2 psi. A Big Mouth provides a LOT of venting.

Now let's say .5 psi were accurate with the Big Mouths open. I can't imagine a scenario where, after they closed, you'd only see an increase to .6 psi

I'm getting another low pressure gauge just to see if the first one is inaccurate. I will report my pressures once I receive it.

AdmiralYoda

ChrisJ said:

Here's my Magnehelic without a snubber, or a valve.

https://youtu.be/Sndnc4ZFFVs


That went on for a few weeks and then I added a 0.015" snubber from Mcmaster.

The snubber is just a fitting with a 0.015" hole in it so it restricts the flow. For those who are afraid of the gauge breaking and venting steam into the room the snubber also restricts that as well.

Just FYI....I was poking around for a compound 0-16oz/in^2 that can also read vacuum. Didn't quite find one but I did come across a snubber from Winters.

https://winters.com/PDF/SSN_SSN-LF.pdf

ChrisJ

AdmiralYoda said:

ChrisJ said:

Here's my Magnehelic without a snubber, or a valve.

https://youtu.be/Sndnc4ZFFVs


That went on for a few weeks and then I added a 0.015" snubber from Mcmaster.

The snubber is just a fitting with a 0.015" hole in it so it restricts the flow. For those who are afraid of the gauge breaking and venting steam into the room the snubber also restricts that as well.

Just FYI....I was poking around for a compound 0-16oz/in^2 that can also read vacuum. Didn't quite find one but I did come across a snubber from Winters.

https://winters.com/PDF/SSN_SSN-LF.pdf

A Dwyer Magnehelic 2350 or 2360 would work for the range you're asking for.
https://www.ebay.com/itm/333250948364?hash=item4d974ded0c:g:SUgAAOSw1wZdFnVd

Or a Dwyer LPG4-D9322N.
Not as nice or as good as a Magnehelic, but it'll get the job done.

Chris_L

Don_175 said:

ethicalpaul said:

I would expect something like .5 to 5 inches of water column with the Big Mouths open. That would be under .2 psi. A Big Mouth provides a LOT of venting.

Now let's say .5 psi were accurate with the Big Mouths open. I can't imagine a scenario where, after they closed, you'd only see an increase to .6 psi

I'm getting another low pressure gauge just to see if the first one is inaccurate. I will report my pressures once I receive it.

If you just want to check your gauge, why not make a manometer? Just attach some clear tubing to one of the drain points below the water line and compare the height of the water in the tubing with that in your gauge glass. The difference in height is the pressure in inches of water. Cheap and accurate.

AdmiralYoda

@ChrisJ My brain hasn't gotten used to inches of water column yet but that is still a great idea. Why can't they make this in oz/in^2 ?!?!?! I may have to pick one up though.

ChrisJ

AdmiralYoda said:

@ChrisJ My brain hasn't gotten used to inches of water column yet but that is still a great idea. Why can't they make this in oz/in^2 ?!?!?! I may have to pick one up though.

You might be able to custom order one in ounces, but inches of water is more standard in really
low pressure gauges.


For you, really all you need to remember is 25 inches is the same as roughly 14 ounces.
So that gauge maxed out is just under a pound. Half of it would be roughly half a pound etc.

Exact numbers don't really matter on our systems.
On my system I found anything higher than a 8 inches, or 1/4 PSI to be annoying.

AdmiralYoda

A side note, and I think it pertains to the OP's question....I have a 16oz/sq.in gauge right now and it works great. My Vaporstat is set to 12oz and when my system shuts down it pulls a vacuum. I have no idea how much....but will that hurt a low pressure gauge?

ChrisJ

AdmiralYoda said:

A side note, and I think it pertains to the OP's question....I have a 16oz/sq.in gauge right now and it works great. My Vaporstat is set to 12oz and when my system shuts down it pulls a vacuum. I have no idea how much....but will that hurt a low pressure gauge?

I guess it depends on how much of a vacuum, but I've never had one damaged by the vacuum produced by my heating system.

It doesn't mean it can't happen, but I haven't had it happen.

AdmiralYoda

It has been working fine for the past two winters so I'm going to say its fine with the vacuum at this point. I've had to adjust the zero setting twice, but only about a half an ounce or so.

Don_175

ChrisJ said:

AdmiralYoda said:

ChrisJ said:

Here's my Magnehelic without a snubber, or a valve.

https://youtu.be/Sndnc4ZFFVs


That went on for a few weeks and then I added a 0.015" snubber from Mcmaster.

The snubber is just a fitting with a 0.015" hole in it so it restricts the flow. For those who are afraid of the gauge breaking and venting steam into the room the snubber also restricts that as well.

Just FYI....I was poking around for a compound 0-16oz/in^2 that can also read vacuum. Didn't quite find one but I did come across a snubber from Winters.

https://winters.com/PDF/SSN_SSN-LF.pdf

A Dwyer Magnehelic 2350 or 2360 would work for the range you're asking for.
https://www.ebay.com/itm/333250948364?hash=item4d974ded0c:g:SUgAAOSw1wZdFnVd

Or a Dwyer LPG4-D9322N.
Not as nice or as good as a Magnehelic, but it'll get the job done.

Thanks for the info. I'll keep the Magnehelic in mind. My snubber and low pressure gauge are Winters. Are they considered a good brand?

ChrisJ

Don_175 said:

ChrisJ said:

AdmiralYoda said:

ChrisJ said:

Here's my Magnehelic without a snubber, or a valve.

https://youtu.be/Sndnc4ZFFVs


That went on for a few weeks and then I added a 0.015" snubber from Mcmaster.

The snubber is just a fitting with a 0.015" hole in it so it restricts the flow. For those who are afraid of the gauge breaking and venting steam into the room the snubber also restricts that as well.

Just FYI....I was poking around for a compound 0-16oz/in^2 that can also read vacuum. Didn't quite find one but I did come across a snubber from Winters.

https://winters.com/PDF/SSN_SSN-LF.pdf

A Dwyer Magnehelic 2350 or 2360 would work for the range you're asking for.
https://www.ebay.com/itm/333250948364?hash=item4d974ded0c:g:SUgAAOSw1wZdFnVd

Or a Dwyer LPG4-D9322N.
Not as nice or as good as a Magnehelic, but it'll get the job done.

Thanks for the info. I'll keep the Magnehelic in mind. My snubber and low pressure gauge are Winters. Are they considered a good brand?

Winters is a common brand.
Not sure if it's good, or bad, but I do know they make both expensive and cheap stuff.

I have a really cheap gauge I put on my pool filter outside that lasted 1 season from Winters. Might also be because it froze at one point too tho............

Don_175

I replaced the gauge and also skimmed for 2 days. Put 8 way in and started boiler. Water level still fluctuates a couple inches at times but usually about ½ inch or so. The new gauge reads less than 0.2 psi max after all main vents close. 

Don_175

My water line is definitely more stable but was still bouncing a bit. rechecked the gauge and during steaming was getting around 0.3 psi. Not sure if it's lower due to my skimming or that it's shoulder season in New England.

ChrisJ

It's going to move up and down a finger width no matter what you do.

More than that could be an issue

ethicalpaul

Don_175 said:

My water line is definitely more stable but was still bouncing a bit. rechecked the gauge and during steaming was getting around 0.3 psi. Not sure if it's lower due to my skimming or that it's shoulder season in New England.

The boiler doesn't know what season it is. Or am I missing your point?

Don_175

ethicalpaul said:

Don_175 said:

My water line is definitely more stable but was still bouncing a bit. rechecked the gauge and during steaming was getting around 0.3 psi. Not sure if it's lower due to my skimming or that it's shoulder season in New England.

The boiler doesn't know what season it is. Or am I missing your point?

I guess I was thinking that since the boiler is not running very long to satisfy the thermostat as it's relatively mild, I might not see quit the same pressure as might occur on a design day when it's running more.

ethicalpaul

Gotcha. Honestly I lost track of our goal here. Are you trying to find out if your boiler is oversized?

Don_175

ethicalpaul said:

Gotcha. Honestly I lost track of our goal here. Are you trying to find out if your boiler is oversized?

No. I spent a lot of time skimming it as the waterline had been very unstable and now it seems pretty stable.
After all of the skimming, I guess I was wondering if the 0.3 psi is an appropriate pressure with boiler steaming and if I might expect the pressure to rise more on a cold winter day.