Is Main Vent (Vent-rite 75) large enough on this one pipe system?

Jack M

Is the main line vent ( a Vent-rite 75) large enough for this system. I'm trying to boost the efficiency on this system to leave a few $ in my pocket after this cold winter.
The boiler takes a while to send steam to the radiators and I’d like to know if my main vent (Vent-rite 75) is adequate.

Back story: Live in a 1500 square foot 2 story farmhouse built in the 1920’s. The house is 4” balloon framing with newer window and little insulation. The steam system is a Crown UPCS4 Boiler (steel boiler) rated at 315 square feet of steam, 75,000 btu hot water, running on a 1gallon per hour Becket RWB burner (like a Beckett AFG). The tag on the boiler says “15 PSI” steam and the USG gauge often reads 10 to 12 psi when running at full pressure (The service tech says these gauges are never accurate and house would have blown up by now if we had that kind of pressure). The one pipe system feeds 4 American Standard radiators (3 column/ 38" tall) on the first floor. Two of the American Standards are 10 section radiators and two are 7 section (3 column) radiators with Vent-rite #1s . There is one smaller “newer” radiator in the second floor bathroom. The first floor layout is pretty open. I’ve never had a complaint about the comfort in the house. We use 1200 gallons of oil a year and keep the thermostat at 60 night/ 68 F during the day. There’s an internal coil in the boiler for domestic hot water (hot water never runs out). The main lines are short and measure 2.5” on the OD. The four longer lines to the radiators measure 1 ¾” OD with runs of 5 ft, 5 ft, 12ft, and 22 ft on the first floor to the American Standard radiators. The pressuretrol is set as low as it can go.
We have lived in the house 10 years and serviced the boiler annually. The heat exchanger soots up between service intervals. Sometimes I get a knowledgeable service tech, sometime I don’t. I picked up Dan Holohan’s “The Lost Art of Steam Heating” and have been learning what I can here on the forum and from the book. The boiler has not been flushed in 10 years (other than the low water device). The same service company did service on the boiler the 10 years prior to us. Oddly, the system ran best one year when a 19 year old (a new hire) did the work. He was so thorough I wrote a letter to the company president. He was promoted to manager (doubt it had anything to do with the letter) and sadly (for me) never left the office again.

nicholas bonham-carter

"He was so thorough....."
No good deed goes unpunished!
the pressure should never exceed 1.5 psi, for comfort and efficiency. I presume you have just one main, and for that, start with one Gorton #2, (check your clearance).--NBC

Abracadabra

A ventrite 75 is a very slow main vent. It's about 1/3 of a Gorton #1 which is a slow main vent as-is. I'd use a couple of gorton #2 at least. There's only one main vent location?

Jack M

GORTON #1 RISER AIR VENT 1/2-3/4" is only $27. A Gorton #2 is going to set me back $82.
The 3 1/2" tall Vent-rite #75 just clears the floor joist. The Gorton #1 should fit (no way a 6.5" tall #2 will fit) I guess I could extent the antler to the side and that would give me some clearance for a larger main vent. But the main vent is a good 5 feet from the boiler as it is. I almost think the radiator on the first floor directly above is closer. Added some images.

Abracadabra

A Gorton #2 is worth 4 Gorton #1, ie. it vents 4x as fast as a #1. It's worth it. You'll easily save the $82 in one heating season. Take out one nipple and the #2 will thread into that coupling.

Fred

It takes almost 4 Gorton #1's to equal the throughput of a Gorton #2. A single Gorton #1 is in no way able to vent your Main suffeciently (Rule of thumb is 1 Gorton #2 for each 20 ft. of 2" pipe. You can elbow that vent pipe over and go between the floor joist. It does not matter that the vent is away from the boiler, you are venting air out of the Mains, not the boiler and you don't want to use your radiator vents to vent the air out of the Mains. They are not designed to accommodate that volume of air. They vent the air out of the radiators. Until you get the air out of the mains, the steam can't push the air out of the radiators.

Jack M

Abracadabra said:

Take out one nipple and the #2 will thread into that coupling.

If the nipple is removed and the Gorton #2 is threaded on at the lower height will I be inviting all sorts of problems? Will the vent fill with rust and crud from higher pipes in the system above and clog?
Other issues? I could do like Fred said and "elbow that vent pipe over and go between the floor joist." if it matters.
Will these old pipes come apart with a large pipe wrench and some elbow grease?

Abracadabra

Jack M said:

Abracadabra said:

Take out one nipple and the #2 will thread into that coupling.

If the nipple is removed and the Gorton #2 is threaded on at the lower height will I be inviting all sorts of problems?

No.

Jack M said:

Will the vent fill with rust and crud from higher pipes in the system above and clog?

No.

Jack M said:

Other issues? I could do like Fred said and "elbow that vent pipe over and go between the floor joist." if it matters.

You could if you want I guess. More work, I don't see any benefit.

Jack M said:

Will these old pipes come apart with a large pipe wrench and some elbow grease?

Yes

What pressure is the system running at?

Steamhead

How "short" are the steam mains?

Jack M

Jack M said:

What pressure is the system running at?

The tag on the boiler says “15 PSI” steam and the USG gauge often reads 10 to 12 psi when running at full pressure. The gauge is not on a pigtail and I have never trusted it. The pressuretrol is set as low as it can go.

Jack M

Steamhead said:

How "short" are the steam mains?

If the "steam mains" are just the 2.5” ( OD) pipes that start as a single pipe coming out the back of the boiler and slanting toward the ceiling and then splitting into two laterals before branching out onto smaller diameter pipes (not main lines) that feed to the radiators, then the Steam Mains total about 19 feet. About 3/4 of it can be seen in this photo:

nicholas bonham-carter

If you have 2 dry returns, then put on 2 Gorton #2's.
Think of these as investments which will cut down on the time the boiler runs to get steam to the radiators. Otherwise, your fuel supplier will be very happy with the extra burn times!--NBC

Jack M

Abracadabra said:

Take out one nipple and the #2 will thread into that coupling.

If the nipple is removed and the Gorton #2 threaded on at the lower height will I be inviting trouble. Will the vent fill will crud from higher lines, clog, spit or create some other problem. I just assumed that someone went to the trouble or raising is so high for a reason.

Abracadabra

Jack M said:

Jack M said:

What pressure is the system running at?

The tag on the boiler says “15 PSI” steam and the USG gauge often reads 10 to 12 psi when running at full pressure. The gauge is not on a pigtail and I have never trusted it. The pressuretrol is set as low as it can go.

Get a gauge on there that works. You need to ensure pressure is running low, otherwise you'll destroy your vents.

If you are 6" above that tee with the vent you should be ok. If you want an extra buffer you can pipe in a couple elbow to get some distance from the tee.

Fred

Taking off the top nipple as Abracadabra suggested will still give you plenty of heigth. Make sure you get that pressure down to a max of 1.5 to 2PSI. Take the Pressuretrol off and clean the pigtail (looped pipe) out and clean the small orifice in the bottom of the pressuretrol where it connects to the pigtail and do get a 0 - 3PSI pressure gauge and mount it on the same pigtail as the Pressuretrol, using a Tee and a couple nipples.

Jack M

The existing Vent-rite 75 sits 6" above the large steam mains. Isn't that "6 inches above" some kind of rule? So I should not go below this existing height of the Vent-rite 75 when I add more vents?

Fred

The vents need to be above the Main, if that is where they are mounted or above the return, if that is where they are mounted. Six inches above whichever one it is mounted on is great.

Jack M

I installed a Gorton #2 on an antler along with the old Vent-rite #75. I fired up the boiler and it took about 57 minutes to heat the 5 radiators in the house (ambient temp inside was 58).
The pressure gauge on the boiler read 10 PSI most of the time and I could hear the water boiling in the boiler. I never heard the Gorton or the Vent-rite make a sound. I thought if I had 10 PSI in the system that Gorton would be howling. Are there any observations of the Gorton that I could make to confirm that its set up correctly?

BobC

Does the pressure gauge read zero when the boiler is not making steam? Does the system ever shut down on pressure?

If the system were running ay 10psi the vents on the radiators would be very loud and probably never stop venting, same goes for the main vents.

Bob

Fred

They are set up correctly but I can teell you if you are running at 10PSI, you are going to ruin all your vents in a hurry. The Pressure trol should be set as low as possible, .5PSI Cut-in and no more than 1.5PSI Cut-out.
The higher the pressure, the slower the steam will move through the system.
The 15PSI rating on the boiler is the max pressure the boiler can take before failure is emminent. That's why there is a 15PSI Pressure Relief valve mounted on the boiler.

Abracadabra

I'd be suspicious of the accuracy of the gauge.

Jack M

Abracadabra said:

I'd be suspicious of the accuracy of the gauge.

From what I've read here on various threads, the gauge mounted to the front of the boiler (the one I'm reading) is not known to be accurate. But Yes, it does read zero when the system has not been running. It takes about 10 minutes to climb to 2-3 psi and and about 40 minutes before it gets up to 10 psi.

I still don't have any confirmation that the Gorton is venting. I certain don't hear anything, or see anything. I does get hot (both main vents do).
I guess I should start looking for a good description of how to hook up a pressure gauge over at the "pressure trol."
I feel like I'm missing something.

BobC

There is a chance the pigtail between the boiler and pressuretrol is clogged so the pressuretrol has no idea what is going on inside the boiler. Do you know if that pigtail is clear?

Bob

Fred

Do you have the Pressuretrol set like we suggested? The very first thing you need to do is take the Pressuretrol off of the pigtail (looped pipe) it is mounted onto and take the pigtail off and clean it out. I am guessing that pigtail is clogged with gunk and the Pressuretrol can not trip like it should at about 1.5PSI because it isn't seeing the boiler pressure (as a result of being plugged)
If it is a Gray colored Pressuretrol, make sure the Cut-in scale on the front is set at the bottom at .5PSI. Take the cover off of the front of it and inside you will see a white wheel. Set that at "1"PSI.
That will give you a Cut-out Pressure of 1.5PSI.
If you have a Pressuretrol that has a clear plastic cover on the front, set the "Main" scale at 1.5PSI and set the Differential scale at "1" Psi. That will give you a Cut-out pressure of 1.5PSI.

As far as adding a low Pressure gauge, simply add a Tee to the pigtail your Pressuretrol is mounted on, add a couple nipples and 90 degree elbows and mount the new gauge on one elbow and the Pressuretrol on the other.
With the boiler running at that pressure and for that long per cycle, the Vents simply can't open after their initial closing.
EDIT: I might also add that if you are still using an 8 degree set-back at night, you are adding to yor problems. Steam boilers don't like more than a 2 to 3 degree set back. Recovery, of more than 2 to 3 degrees, especially in very cold weather, is almost impossible, in a reasonable heating cycle.

Abracadabra

Add a 0-3PSI gauge.

Jack M

I'm trying to familiarize myself with the Pressuretrol. These are new to me and have electricity attached to them. I'm not always confortable around old electric wires.

Jack M

I still don't get the Gorton #2. It is definitly not venting at all. Same with the Vent-rite #75. I took the Vent-rite off and then fired up the boiler. Immediately I had steam coming out of the bare pipe. Then I put the Vent-rite back on and took the Gorton #2 off. Again, within 30 seconds steam was billowing from the open pipe. Why isn't anything coming out of these vents when they are attached?

BobC

That looks like it is set to trip at about 1.5 PSI, make sure the pigtail is not blocked.

Bob

Steamhead

Remove the vents when they're cold, hold them vertically and try blowing into them. You'll know if they're stuck closed.

Fred

A

Jack M said:

I still don't get the Gorton #2. It is definitly not venting at all. Same with the Vent-rite #75. I took the Vent-rite off and then fired up the boiler. Immediately I had steam coming out of the bare pipe. Then I put the Vent-rite back on and took the Gorton #2 off. Again, within 30 seconds steam was billowing from the open pipe. Why isn't anything coming out of these vents when they are attached?

As I said earlier, they are too hot and there is too much pressure for them to open as they should. That is a very old Pressuretrol, if you clean out the pigtail and the pressure still builds like it is doing now, the Pressuretrol probably has failed and may need to be replaced. You have to get the pressure down to a normal range and stop using an 8 degree set back on the thermostat.

Jack M

I was able to confirm that when the Gorton #2 is cold it vents. I can feel the air escaping. I had been looking for really hot air but this air is not hot and not steamy. Just air that makes no sound. Not very exciting for $70. As soon as the Gorton #2 gets hot it stops venting. I put a infra red thermoter on it and at 90 degrees F it was definitly not venting.
The steam pipes naturally get really hot. Over 200 degrees and because the Gorton is attached to some of those pipes (remotely) it seems like it gets hotter and hotter too. I can smell the paint curing on the Gorton #2.

Jack M

I took the cover off the pressuretrol to look at things. In order to see if the pigtail is clogged, it looks like the blue wires need to come off (after shutting down the power) and then the whole pressuretrol screws off the pigtail.

Jack M

Removed the pressuretrol and removed the pigtail. The pigtail was clogged completely. I worked at it a while and got it cleaned out. Reinstalled the pigtail and pressuretrol and fired up the boiler. The pressure on the boiler's gauge eventually climbed to 9 psi and after the boiler ran for 30 minutes. By that time three quarters of each (5 total) radiator was hot (the end of each radiator was still cold to the touch). I will look for pressuretrol options and look for a way to attach a seperate pressure gauge near the pressuretrol pigtail. I'm still not understanding the roll of the pressuretrol. If the pressuretrol shut the system down every time the boiler reached a pressure of 2 or 4 psi, wouldn't the radiators be waiting all day for steam?

nicholas bonham-carter

Its very possible that the pigtail blockage extends into the boiler, or into the orifice of the pressuretrol, so more cleaning is needed, (maybe even pressuretrol replacement).
When the pressuretrol shuts down the burner at 10 psi, the steam rapidly begins to condense, and a vacuum develops. The main, and radiator vents should open to let air back into the system. Probably the heat coming off the steam line is causing the Gorton vent to close prematurely, causing your fuel supplier to rub his hands with glee, as the system uses 30-50% more fuel than it should. The only worry he has is whether your fingers, shivering with cold, can make out the check when his bill arrives!
You may well need more than that one Gorton, so think of it as an investment in retaliation to high fuel consumption. If you can't get the pressuretrol working properly, then replace that as well.--NBC

BobC

i suspect there may be another clog inside the boiler tapping or at the base of the pressuretrol as NBC said. When the boiler is at pressure does that mercury bulb start to tilt?

As old as it is it could have failed but make sure everything is clear before replacing it.

Bob

KC_Jones

Jack M said:

Removed the pressuretrol and removed the pigtail. I'm still not understanding the roll of the pressuretrol. If the pressuretrol shut the system down every time the boiler reached a pressure of 2 or 4 psi, wouldn't the radiators be waiting all day for steam?

Technically the pressuretrol is a safety device to keep the pressure down on your system. The true goal (if you are not over sized terribly) is to get the system to run at a low pressure and NOT trip the pressuretrol. Higher pressure steam moves SLOWER so all you are doing with the pressure you are building is packing steam into a pipe, but you are not heating the house faster you are actually heating it slower than you could. I was checking out your pictures and it looks like you actually have 2 mains. It appears the piping comes up from the boiler and splits and goes 2 different directions (if so that piping is actually incorrect). It appears as though you are only venting one side of this, but can't tell for sure. If that pipe coming up from the boiler splits and goes 2 different ways you need to vent BOTH of those as they are both main lines. If your pressure is indeed running high (verify after installing low pressure gauge) your fuel consumption should drop by getting the pressure down. The goal should be to do this with venting again as long as you aren't terribly over sized. Have you measured all your radiators to compare that to the boiler size? This is a good exercise to see where your system is now and should you ever need a boiler replacement you will know what size boiler you need.

Jack M

KC_Jones said:

Jack M said:

Removed the pressuretrol and removed the pigtail. I'm still not understanding the roll of the pressuretrol. If the pressuretrol shut the system down every time the boiler reached a pressure of 2 or 4 psi, wouldn't the radiators be waiting all day for steam?

Technically the pressuretrol is a safety device to keep the pressure down on your system. The true goal (if you are not over sized terribly) is to get the system to run at a low pressure and NOT trip the pressuretrol. Higher pressure steam moves SLOWER so all you are doing with the pressure you are building is packing steam into a pipe, but you are not heating the house faster you are actually heating it slower than you could. I was checking out your pictures and it looks like you actually have 2 mains. It appears the piping comes up from the boiler and splits and goes 2 different directions (if so that piping is actually incorrect). It appears as though you are only venting one side of this, but can't tell for sure. If that pipe coming up from the boiler splits and goes 2 different ways you need to vent BOTH of those as they are both main lines. If your pressure is indeed running high (verify after installing low pressure gauge) your fuel consumption should drop by getting the pressure down. The goal should be to do this with venting again as long as you aren't terribly over sized. Have you measured all your radiators to compare that to the boiler size? This is a good exercise to see where your system is now and should you ever need a boiler replacement you will know what size boiler you need.

This is helpful. I removed a few of the vents from some of the radiators. They do heat up much faster with the vents removed. Eventually steam starts to come out of the holes in the radiators. But not like a guiser, the steam just waffles out slowly. If there is really 10 psi of pressure and all this heat building up in the system shouldn't this pressure be more apparent with the vents removed? ...... still learning.

KC_Jones

I think your gauge it probably wrong, but it's just guessing until you get a good gauge on there and see what is really going on. those 0-30 PSI gauges are basically useless.

Fred

The other thing to remember is that the Pressuretrol will control the max pressure and should keep it at no more than 1.5PSI. This typically only happens on very cold days when the boiler runs for extended periods of time. Most of our boilers run at between 2 ounces up to about 12 ounces. At about 1.5PSI, the system is about as full of steam as it can possibly handle and the Pressuretrol shuts the boiler down long enough to allow that steam to condense and give off its heat before re-starting the boiler to produce more steam.
If you are actually running at the pressures your gauge indicates, the vents can't open. They close at about 130 degrees but they also have what is called a "Drop-out" pressure (the pressure at which they can reopen to let more air out during the next firing of the boiler, especially if the boiler does do some short cycling). At your pressures (again assumming your gauge is anywhere near accurate), they simply don't have time to re-open so that more steam can enter the radiator.
One final note, depending on how cold it is outside and how long the boiler runs to satisfy the thermostat, most radiators will not get hot all the way across with each heating cycle. When the Thermostat is satisfied, the boiler will shut down, regardless off how full or hot the radiators are.

neilc

guys, look close at that last pressuretrol picture,
and the pigtail,
which looks like it's piped to the top of the low water cutoff,
that pigtail isn't applied correctly, is it?
don't I understand that one wouldn't want water right up against the ptrol diaphragm?
shouldn't there be a taller nipple and air gap above the pigtail and that 90?
or get a full circle pigtail instead of the 270 , , ,

OP, can we get a wide shot of the Ptrol, pigtail, and low water cutoff

Fred

neilc said:

guys, look close at that last pressuretrol picture,
and the pigtail,
which looks like it's piped to the top of the low water cutoff,
that pigtail isn't applied correctly, is it?
don't I understand that one wouldn't want water right up against the ptrol diaphragm?
shouldn't there be a taller nipple and air gap above the pigtail and that 90?
or get a full circle pigtail instead of the 270 , , ,

OP, can we get a wide shot of the Ptrol, pigtail, and low water cutoff

Yes, it is piped on top of a McDonnell Miller #67. It is ok to put it there (although that tapping is notorious for plugging up) but you are right, it looks like the Pressuretrol is below the boiler water level, which is also part of his problem, in terms of it being able to sense pressure. He needs an upright pigtail or he needs to put a 4" to 6" nipple on that elbow and then mount the Pressuretrol. Good Eye neilc!