Steam problems (Toronto) -- help!

Stuart Rogers

Please see my message below in the Controls section, Subject: "3 Pressuretrols??" (Oct. 15/07). One of the respondents advised me to repost in this section of the Wall.

Any help and advice is greatly appreciated. Thank you!

Stuart

Stuart Rogers

cycling the boiler harms pipes?

Since we have such poor control of our system at the moment, and the seasonal temperatures are mild, I have proposed that we operate our boiler for only a couple of hours in the morning and again a couple of hours in the evening -- by operating the wall switch that powers the controller.

The wind-tunnel expert who normally looks after the system is out of the country but has objected via his wife, the superintendent, that "leaving the boiler on for two hours is not good for the piping and there is not enough steam buildup to heat the building."

Is that true? Will our 82-year-old pipes be damaged by this pattern of operation? Will our Weil-McLain 1280 boiler and uncontrolled rads fail to heat a 4-storey, 25-unit brick building in 2-4 hour blocks when the outside temperature varies between 5-13 degrees C (41-55 F)?

Your help is appreciated,

Stuart

Unknown

There's some merit to that

If you could keep the boiler hot (180 to 200 degrees F.) during the day, it wouldn't take as much of a beating from expansion and contraction.

Until you get control of the steam running around in the returns from failed steam traps, it's not a bad idea to stop the steam during parts of the day. Your tennants will be more comfortable.

Noel

ttekushan_3

Hurt the steam pipes?

Okay, that's a new one.

I used to do what you are suggesting in a building that at the time had steam distribution problems. Before "tweaking" the system and balancing it with creative main and return venting (it was a two-pipe system), I or the landlord would flip the switch for a predetermined amount of time. As a matter of fact, the south boiler was fitted with a timer specifically for this purpose, reverting to thermostat operation when median outdoor temps dropped enough. Full cycle length in my case was about 50 minutes. It worked out well because everyone got heat, and the heat load in mild weather really is so minimal.

Of course, maybe the steam pipes survived this amazing stress (!?) at that time because they were merely 75 years old! Now that they're 80 years old they'd just "bust apart" kind of like the Blues Mobile at the end of the Blues Brothers movie. Or something like that.

Its hard to justify that "hard on the pipes" belief. Basically I see a super thats got turf issues and commands you to believe that everything's fine under his control, even though the evidence screams otherwise. Your legitimate attempt to learn about solutions to what are likely simple problems is a threat.


There are a couple private parochial schools in my area with this problem. Everyone complains about the heat, and the people I know who teach there know I could solve the problems... Trouble is, the maintenance guy won't let anyone in. Apparently he's got everyone intimidated. So nothing will happen. I say, let him quit when he huffs and puffs and threatens to do so if someone's to be brought in to solve particular problems. Everyone would be better off.

-Terry

Stuart Rogers

keeping the boiler simmering

Hi Noel,

Thanks for the reply. Unfortunately, I have no clue how to keep the boiler merely warm between full firings. It's a Power Flame controller, and I haven't been able to locate any user manuals or theory of operation information. It appears capable of more than it's doing, since there are the two pressuretrols that you say are for hi/lo ops, and there's also a "modulation" control (set to minimum). I have no clue what that does.

We've located a steam pro in Toronto (Bell Combustion), and supposedly we'll be able to meet with someone later this week. I'd write down all my questions for him, but he'd probably turn and flee when he saw the stack of paper ;-)

thanks again,
stuart

Stuart Rogers

re; hurt the pipes?

Terry, thanks for backing me up! Our super's husband is a great guy, and yes, he does have kind of a "proprietary" attitude about the boiler. Unfortunately, he has only a partial understanding of low-pressure steam heat, and so has allowed the system to get out of hand while also stressing it with high temps/pressures. See my reply to Noel in the previous message -- help is on the way!

best,
Stuart

ttekushan_3

Noel

Naturally, I was typing in my reply while distracted and Noel's post appeared before mine, making it sound as though I'm belittling the point of thermal stress. Its just that in heating systems there are so many angles and offsets in the piping that take up the slack (and the fact that the temperatures and pressures in heating systems are very very low) The pipe stress failures are almost unheard of. And if it was to show up it would have shown up decades ago.

Now. High pressure industrial steam is a whole different ball game. [hey, how 'bout those Cleveland Indians!? HA worked in. hehe] Those systems get shut down maybe once a year and require a supervised start-up that is slowwww in order to prevent those long pipes from expanding too quickly and to prevent catastrophic water hammer.

Its merely my point that low pressure heating is low stress.

Unknown

A TREMENDUS SHAME,

> Naturally, I was typing in my reply while

> distracted and Noel's post appeared before mine,

> making it sound as though I'm belittling the

> point of thermal stress. Its just that in

> heating systems there are so many angles and

> offsets in the piping that take up the slack (and

> the fact that the temperatures and pressures in

> heating systems are very very low) The pipe

> stress failures are almost unheard of. And if it

> was to show up it would have shown up decades

> ago.

>

> Now. High pressure industrial steam is a

> whole different ball game. [hey, how 'bout those

> Cleveland Indians!? HA worked in. hehe] Those

> systems get shut down maybe once a year and

> require a supervised start-up that is slowwww in

> order to prevent those long pipes from expanding

> too quickly and to prevent catastrophic water

> hammer.

>

> Its merely my point that low pressure

> heating is low stress.



I`m in Ontario, but most try to covert from steam to HW because they think there is no-one left alive to service them, or too cheap minded to bear the costs!
Then the game begins,,I have seen it!!

Dave

Unknown

A TREMENDUS SHAME,

I`m in Ontario, but most try to covert from steam to HW because they think there is no-one left alive to service them, or too cheap minded to bear the costs!
Then the game begins,,I have seen it!! Steam rules.

Dave

ttekushan_3

Of pressuretrols and venting.

And another thing. How are the returns vented in this system? It doesn't appear to me from the photos that the receiver is vented. Lousy venting with a large boiler can cause the boiler to flip between high and low fire (based on the staging pressuretrol setting). Low fire before saturation of all pipes and radiators with steam allows the remaining air to expand also. So no heat in some areas.

Just this morning, I looked at an apartment building two-pipe steam system. The usual preseason procedures. The owner said that there's one group of apartments that never seem to warm up. All stacked one above the other all the way up to the fourth floor. So I looked for a return that heads below the water line. Sure enough, the end of that return had a cap where there was supposed to be a vent. There was a new vent on the shelf there. Installed. Fired it up; problem solved. It had been like that for years!

It really is fun to solve these problems. With steam the problem isn't usually near the symptom. Yet when you figure it out its usually so simple-- and has huge effect on how effectively and efficiently the system operates.

-Terry (again)

Unknown

Terry,

Are you gonna come-up here and fix-it??
Not likely.

Dave

Stuart Rogers

thermal stress

Not to worry, Terry. You (and my aerodynamics engineer) were talking about the distribution pipes and you (and I) both thought it was silly to say cycling a low pressure boiler could harm them. Noel was talking about the boiler itself, and we can all see the point that it would be easier on the boiler not to go through a lot of high temperature swings. I don't see any contradiction between your and Noel's comments. IOW, you were contradicting my aerodynamics engineer and not Noel

Stuart Rogers

Re: of pressuretrols and venting

There is an open pipe on the receiver (and a large water stain fanning out on the wall above it). I can feel moderately warm moist air coming out of it. The pipe with the arrow pointing to it in the revised photo attached is open at the top.

There is also a vent on one of the mains, but it's painted over and I don't think it's working. Another main on the other wing has a short capped vertical pipe, so I think a vent used to live there but is gone.

Something I noticed when I checked this evening is that not only is there the sound of running (trickling, draining) water from the boiler when the burner shuts off, there is also a long injection of cold fresh water into the condensate receiver. Every time the burner shuts off. We must be adding a huge amount of fresh cold water (and oxygen and CO2) every heating season. I have a feeling the fixes I'm identifying are going to pay for themselves in a fairly short time...