Equalizer and near-boiler piping

Jack M

Does this one-pipe steam (Crown/Dunkirk) boiler piping have an equalizer? The riser starts off the back of the boiler and has what seems like a very long (7-ft) sloping header that distributes steam to six radiator feeds in the loop. At the end of the very long header, a 1.5" drops at a "T" with a main valve on antlers above. The return travels to the base of the boiler. Does this return (mud leg) function as the equalizer?

Jamie Hall

Nope

Intplm.

It doesn't appear to be. Tough angles on those pictures but there doesn't seem to be a equalizer.

ChrisJ

Boy is that smoke pipe close to combustible material.

ethicalpaul

Luckily the Equalizer doesn't do much. How well does it operate?

And why is it mounted so dang high?

delcrossv

ethicalpaul said:

And why is it mounted so dang high?

Thought that was weird myself.

So they didn't have to lower the return or lengthen the risers.

Jack M

This boiler is from the early 1970s (this 1920 house had a coal-fired "snowman" steam boiler that was converted to oil burning. In 1936 there was a flood in New England and there is a "mud line" around the walls of the basement. The boiler is installed just above that line. I guess that the owner was concerned about losing the boiler to the next flood. That is just a guess.
The "snowman" was on the adjacent side of the chimney (you can see the blocked chimney hole), and the old boiler's riser appears to have been connected at the very end of the line. No idea why the boiler would have been moved to a different location unless they needed to move the chimney hole higher.
I appreciate the feedback on the equalizer. I watched someone's (a member's) video of how a boiler still runs dry when using a Hartford loop and it got me thinking about the equalizer. Steam is never dull.

Jack M

ChrisJ said:

Boy is that smoke pipe close to combustible material.

Yes, if a Megasteam were installed at the location of the old coal boiler (using the old thimble) and placed on the floor, the vent pipe would meet Burnham's 18" requirement for clearance to combustibles.

Jack M

ethicalpaul said:

Luckily the Equalizer doesn't do much. How well does it operate?

Seems to work just fine. I have lost three good service technicians in the past 8 years (retirement) and that is a concern.

ethicalpaul

Good. Basically as long as you don't see the water line plunge lower during a call for heat, it's not surging, and it's doing fine.

Jack M

ethicalpaul said:

Good. Basically, as long as you don't see the water line plunge lower during a call for heat, it's not surging, and it's doing fine.

Last year I accidentally overfilled (water coming out the Main Vent) and all that water flushed debris into the wet return (mud leg) and I ended up with surging. I had to flush that mud leg out twice before things returned to normal. Lesson learned, don't get distracted or walk away when replacing water from a flush of the low-water-cutoff.

So the job of the equalizer is to do what?
Note: I just found NJ Steam Homeowner's video on Equalizers thank you. https://youtube.com/watch?v=6ZLg3fqU1MQ&list=PLJnFCP6aLvI_wpKz-QjbkZokT0yKj4-bU&index=6

ethicalpaul

Yes, that's my video. There is debate about this, but I have shown the equalizer's only valid purpose is to let any water in the header drain away from the supply pipes back into the boiler. So it should be called the "header drip" not the "equalizer".

There is a theory that the equalizer somehow keeps water in the boiler while it is operating. I have disproven that with my video, although not everyone accepts that (although they don't provide any evidence to counter my claims).

There is another theory which I think was the effect of people scrambling to find an actual purpose for the equalizer after I showed it doesn't really do anything. They say if your wet return catastrophically fails, then the equalizer will prevent the water from siphoning out of the boiler. This is true enough, but it won't prevent your boiler from running out of water because the boiler is generating steam which ends up in the wet return anyway.

ChrisJ

Which, since it's 2024 and not 1920 makes a 2nd LWCO far more useful than an equalizer.

Sylvain

ChrisJ said:

Which, since it's 2024 and not 1920 makes a 2nd LWCO far more useful than an equalizer.

And, maybe, on the boiler body, a temperature switch opening at something like 220° (with some additional circuitry for alarm and prevention of automatic restart ).

ChrisJ

Sylvain said:

ChrisJ said:

Which, since it's 2024 and not 1920 makes a 2nd LWCO far more useful than an equalizer.

And, maybe, on the boiler body, a temperature switch opening at something like 220° (with some additional circuitry for alarm and prevention of automatic restart ).

You know, that sounds like a really good idea.

ethicalpaul

I agree, Chris. If the governing bodies were actually concerned about boiler leaks causing fires and/or explosions, they should:

- mandate two completely separate LWCO
- mandate two completely separate pressure controls
- mandate two completely separate pressure relief valves

For those last two, they could at least make it be plumbed far above the water line, instead of so close to it that it gets gunked up.

ChrisJ

ethicalpaul said:

I agree, Chris. If the governing bodies were actually concerned about boiler leaks causing fires and/or explosions, they should:

- mandate two completely separate LWCO
- mandate two completely separate pressure controls
- mandate two completely separate pressure relief valves

For those last two, they could at least make it be plumbed far above the water line, instead of so close to it that it gets gunked up.

You'd think on a home heating steam boiler there's a cheaper easier solution to a pressure relief.
Something like a wax plug that melts and blows out at low pressure.

15 PSI on home heating steam is completely obnoxious really.

ethicalpaul

I'd like to see a pressure relief "whistle" that make an annoying teakettle sound at 5psi

ChrisJ

15 PSI relief on a home heating steam boiler reminds me of this from The Burbs.

https://youtu.be/oaVIWpUMcd4?si=3Ms8lh-8O2vXQJoN

pecmsg

Jack M said:

This boiler is from the early 1970s (this 1920 house had a coal-fired "snowman" steam boiler that was converted to oil burning. In 1936 there was a flood in New England and there is a "mud line" around the walls of the basement. The boiler is installed just above that line. I guess that the owner was concerned about losing the boiler to the next flood. That is just a guess. The "snowman" was on the adjacent side of the chimney (you can see the blocked chimney hole), and the old boiler's riser appears to have been connected at the very end of the line. No idea why the boiler would have been moved to a different location unless they needed to move the chimney hole higher. I appreciate the feedback on the equalizer. I watched someone's (a member's) video of how a boiler still runs dry when using a Hartford loop and it got me thinking about the equalizer. Steam is never dull.

That flood line was from the hurricane of 1938. That is a measurement of what can happen. We’ve seen nothing even close since. 

ChrisJ

pecmsg said:

Jack M said:

This boiler is from the early 1970s (this 1920 house had a coal-fired "snowman" steam boiler that was converted to oil burning. In 1936 there was a flood in New England and there is a "mud line" around the walls of the basement. The boiler is installed just above that line. I guess that the owner was concerned about losing the boiler to the next flood. That is just a guess.
The "snowman" was on the adjacent side of the chimney (you can see the blocked chimney hole), and the old boiler's riser appears to have been connected at the very end of the line. No idea why the boiler would have been moved to a different location unless they needed to move the chimney hole higher.
I appreciate the feedback on the equalizer. I watched someone's (a member's) video of how a boiler still runs dry when using a Hartford loop and it got me thinking about the equalizer. Steam is never dull.

That flood line was from the hurricane of 1938. That is a measurement of what can happen. We’ve seen nothing even close since. 

https://en.wikipedia.org/wiki/1938_New_England_hurricane

CLamb

ChrisJ said:

You'd think on a home heating steam boiler there's a cheaper easier solution to a pressure relief.
Something like a wax plug that melts and blows out at low pressure.
15 PSI on home heating steam is completely obnoxious really.

Steam locomotives and tractors would have a lead or other alloy plug which melted when the temperature got too high. A device I've seen for emergency pressure relief is simply a diaphragm of metal foil which ruptures when pressure gets too high.

Sylvain

CLamb said:

Steam locomotives and tractors would have a lead or other alloy plug which melted when the temperature got too high. A device I've seen for emergency pressure relief is simply a diaphragm of metal foil which ruptures when pressure gets too high.

It won't stop the burner though.

SteamingatMohawk

Use of a destructive relief mechanism, like a wax plug, opens the relief path, but doesn't stop relieving until all the available steam energy is expelled.

How can that be better than a relief valve that resets after a reduction in pressure?

I have no background in steam locomotives and tractors to comment on those devices. However, read this.

https://www.steamlocomotive.com/appliances/safetyvalve.php

ethicalpaul

SteamingatMohawk said:

Use of a destructive relief mechanism, like a wax plug, opens the relief path, but doesn't stop relieving until all the available steam energy is expelled.

How can that be better than a relief valve that resets after a reduction in pressure?

Because relief valves fail to activate

ChrisJ

SteamingatMohawk said:

Use of a destructive relief mechanism, like a wax plug, opens the relief path, but doesn't stop relieving until all the available steam energy is expelled.

How can that be better than a relief valve that resets after a reduction in pressure?

I have no background in steam locomotives and tractors to comment on those devices. However, read this.

https://www.steamlocomotive.com/appliances/safetyvalve.php

When I said it I was picturing a really cheap simple pressure relief that won't / can't stick shut.

Similar, fuses are safer than circuit breakers in that they cannot fail to open. They may fail sooner than expected, but they won't stick on.

SteamingatMohawk

@ethicalpaul That's a maintenance issue...how many boiler owners actually hand lift the valve periodically and/or setpoint check the valves?

A search on home boiler (low pressure) relief valve testing hasn't revealed a "code" reference. There are multiple sites that talk about quarterly manual testing ( I assume hand lifting) and annual pressure setpoint testing. The manual for my boiler has no information on relief valve maintenance.

@ChrisJ There's a big difference between an open circuit and a boiler at pressure "open to the atmosphere".

ChrisJ

SteamingatMohawk said:

@ChrisJ There's a big difference between an open circuit and a boiler at pressure "open to the atmosphere".

Please explain?

EBEBRATT-Ed

Ther is a cheaper solution to a relief valve. It's called a pipe plug. If you trust your pressure control to fail and your pigtail to never plug, go for it. It's called insanity.

If the boiler stays at low pressure under 2 psi (at least on residential) the relief valve should never open. It should be tested occasionally but usually they never fail unless you rund the operating pressure above 12psi when they can weep and rust shut.

I know of a "technician" who couldn't figure out why an oil burner was locking out so he took the cad cell control out and hot-wired around it. It ran that way for a year until someone else (this one had a brain) serviced the burner.

I know of many old steam boilers that were so old they never had low water cutoffs installed and survived for years

You don't need any controls until something goes wrong.

There are millions of old gravity hot water boilers installed that have nothing more than a strap on aqustat and a thermostat.

ChrisJ

EBEBRATT-Ed said:

Ther is a cheaper solution to a relief valve. It's called a pipe plug. If you trust your pressure control to fail and your pigtail to never plug, go for it. It's called insanity.

If the boiler stays at low pressure under 2 psi (at least on residential) the relief valve should never open. It should be tested occasionally but usually they never fail unless you rund the operating pressure above 12psi when they can weep and rust shut.

I know of a "technician" who couldn't figure out why an oil burner was locking out so he took the cad cell control out and hot-wired around it. It ran that way for a year until someone else (this one had a brain) serviced the burner.

I know of many old steam boilers that were so old they never had low water cutoffs installed and survived for years

You don't need any controls until something goes wrong.

There are millions of old gravity hot water boilers installed that have nothing more than a strap on aqustat and a thermostat.

I feel you completely missed the point.
A pipe plug isn't a safe solution.


My suggestion, if anything, is safer than a mechanical pressure relief which are known to get stuck shut. It certainly wasn't a pipe plug. I also mentioned 15 PSI seeming way too high for a residential heating system. Again, not a pipe plug.


Unless my memory is failing me, the recommendations were for safer lower pressure solutions as well as multiple LWCO's, not to remove safeties.

bburd

@EBEBRATT-Ed said:

"There are millions of old gravity hot water boilers installed that have nothing more than a strap on aqustat and a thermostat."

Oh yes. My friends had just bought an old house. It had a "snowman" boiler on a gravity hot water system converted to oil with forced circulation. Service tags showed regular professional attention.

When I couldn't find a safety valve I explained why they needed one and 

suggested they call their oil company, which promptly came out and installed one with profound apologies for not noticing this obvious safety hazard during their regular servicing.

SteamingatMohawk

@ChrisJ said Please explain?

The energy source at a blown fuse or a tripped breaker does not endanger anyone at that location. Activation of the safety device stops the energy flow.

A boiler with an open path to the immediate area while spewing the residual built up energy in the boiler , including steam and hot water, is a hazard (even with the discharge pipe exit near the floor). At least with a functioning relief valve, the total energy released is limited to the amount expelled until the valve gets to its reset point. Any device that ruptures/melts does not stop the energy flow.

ChrisJ

SteamingatMohawk said:

@ChrisJ said Please explain?

The energy source at a blown fuse or a tripped breaker does not endanger anyone at that location. Activation of the safety device stops the energy flow.

A boiler with an open path to the immediate area while spewing the residual built up energy in the boiler , including steam and hot water, is a hazard (even with the discharge pipe exit near the floor). At least with a functioning relief valve, the total energy released is limited to the amount expelled until the valve gets to its reset point. Any device that ruptures/melts does not stop the energy flow.

True.

But my reasoning is lot less energy is going to be released at 5 PSIG than 15 PSIG. Or is that incorrect?

My thoughts were, especially at 15 PSIG if somehow that pressure was reached, something is incredibly wrong and dangerous and you're at the shut it down for good until someone looks at it point. So I wouldn't want the valve closing and building pressure again. Turning my basement into a sauna still seems safer than letting the system build pressure again at that point.

Regardless, why are mechanical pressure reliefs for residential steam systems 15 PSIG and not lower like 5? For hot water boilers it's very understandable. For steam, it's confusing.

SteamingatMohawk

First, on the subject of plugs vs. relief valves:
It depends on the scenario you are suggesting. If it's a one shot deal rather than going on for "hours" at a time, there would be a difference between the energy properties of the steam. Here are some numbers, just for the heck of it. One unknown would be the actual number of pounds of water in the boiler available to form steam. But once all the water is at saturation temperature, all the energy goes into making steam.

Pressure (psig/psia) Temperature (F) Total heat of steam (BTU/LB)
0/ 14.7 212 1150.5
5.3/20.0 228 1156.3
30.0/15.3 250 1164.1

At the different pressures/temperatures there is only about 14BTU/LB (1%) difference in the heat content. There is essentially no difference.

With the rupture disc/plug/etc. option once the initial pressure is released, continuing to create steam at atmospheric pressure would release approximately the same amount of heat regardless of the starting point (ignoring the difference in liquid water energy content at the different starting temperatures).

At a 100,000 BTU/HR steaming rate making steam from water (970BTU/LB to make steam out of liquid 212F water) would make 103 LB of steam. Each LB of steam would occupy 26.8 CUFT. Each hour then would create 2760 (103*26.8) CUFT/HR of steam. A 1000SQFT basement 8 feet tall would be filled every 2.9 (8000/2760) hours.

While that seems like a long time, I can’t imagine any company or governing body allowing such a possibility by using a self-destructive protective means, as suggested.

Second regarding the 5 vs 15 suggestion:

Back in March 2022 I had an HH discussion titled, "Low Pressure Heating Boiler Regulations" that just happened to mention the 15psig relief valve and the 30psig gauge. Here’s the URL: https://forum.heatinghelp.com/discussion/187854/low-pressure-heating-boiler-regulations

ChrisJ

@SteamingatMohawk. Perhaps you're right.
You have many good points that's for sure.

ethicalpaul

A basement wouldn't be filled with steam. It would condense immediately into water.

EBEBRATT-Ed

@ethicalpaul

Not true it gets very foggy real fast everything gets hot and steamy takes a while to dissipate.

@ChrisJ I would never condone a pipe plug you missed the last sentence " It's called insanity."

ChrisJ

EBEBRATT-Ed said:

@ethicalpaul Not true it gets very foggy real fast everything gets hot and steamy takes a while to dissipate. @ChrisJ I would never condone a pipe plug you missed the last sentence " It's called insanity."

Oh I know that.
It seemed like you were suggesting I would.

I'm hoping no one on this forum would.

ethicalpaul

EBEBRATT-Ed said:

@ethicalpaul

Not true it gets very foggy real fast everything gets hot and steamy takes a while to dissipate.

that's not steam, it's condensation. Steam is invisible.

You may think I'm picking nits here, but no. @SteamingatMohawk is using calculations to determine the cubic feet of steam, but they don't apply unless the room is actually filled with steam (which it's not, not by a long shot)

Intplm.

@ethicalpaul

Have you ever looked into the Hartford Steam Boiler Insurance Company?
Im not sure if they are a steam boiler insurers still, but they have shown expertise in steam and steam heating concerns for more then one hundred and fifty years.
They started when steam power was in its infancy and they implemented many steam heat and steam energy safety requirements.
You might enjoy their history.
Looking into them you might find some of the answers as to why things are done the way they are to this very day.
It might be worth a look?

ChrisJ

Intplm. said:

@ethicalpaul Have you ever looked into the Hartford Steam Boiler Insurance Company? Im not sure if they are a steam boiler insurers still, but they have shown expertise in steam and steam heating concerns for more then one hundred and fifty years. They started when steam power was in its infancy and they implemented many steam heat and steam energy safety requirements. You might enjoy their history. Looking into them you might find some of the answers as to why things are done the way they are to this very day. It might be worth a look?

I'm not so sure steam engines were in their infancy in the 1860s?

I was under the impression it was quite mature by then.