steam opions on 2 stage gas valve

Ross_7

I was just thinking about this the other day. I was also thinking that Asco makes a modulating gas valve, with 135ohm input, there is a 135 ohm modulating Honeywell Pressuretrol (Vaporstatwith a 0-1psi adj.) range output on it.I would think it feasible to match them both up? Available in 24VAC. Quite interesting.
Ross

Chas_2

steam opitions 2 stage gas valve

Just wondering ,what's the thoughts on using a 2 stage gas valve to stop or shorten mid and end of the cycle short cycling on a steam boiler which is controlled by a heat timer boiler controller .The boiler runs about 15 to 20 minutes and distrubites steam so so then after the mains have vented the boiler starts it cycle based on the heat timer 20 minute run cycle after steam had reached the sensor .I was planning to use the 2 stage gas valve to lower the input once the system has 12 ounces of pressure and if the pressure drops below 7 ounces the hi fire would kick back in .Does this set up make sense and how do you feel it would affect the gas comsumpition .as of now there alot of short cycling as i staed at the mid to end of the cycle and as the outdoor is high it's worse .Thanks for any input peace and good luck clammy

ttekushan_3

great idea

I'm aware of Steamhead, Gerry Gill, BoilerPro doing this (and stage firing multiple boiler systems) for steam. If memory serves, numbers on the order of 30% fuel savings have occurred.

I just did this to a somewhat oversized LGB last week. The system could build pressure like crazy after the initial 15 minutes of operation. The low fire kicks in and the pressure holds pretty steady, with a very slight creep upwards to assure cold weather heating but not enough for it to shut off on pressure within most heating cycles.

Its a personal preference, but on most apartment buildings I prefer having a pickup factor of almost 1.5, but only with the ability to lower the fire to the ideal 1:1 load match for "cruising."

-Terry

Chas_2

Thanks

Thanks for your input ,as i staed the mid and end f the cycle short cycling is ridilous and even with tight permeters it's hard because of by the time the burners kick back on my steam pressure is only about 4 to 6 ounces and i believe thatthe drop in pressure also hinders some of the steam distrubition .The heat timer also in my mind does creat issues i personally don't like em and am seeking better control set up .i feel even a remote sensor t/stat or averaging t/stat would be a better fit then pre determined boiler run time ?what's yout thoughts on that and system performace between the two ,thanks again for the information ,happy holidays and of course may peace and good luck follow you to where you may roam clammy

Unknown

Ross, does Asco have

a web site I would be interested in looking into that modulating valve?

Ross_7

ASCO

Hi Tim,
Yes, I believe it's one word, www.ascovalve.com, or just www.asco.com, and there is a link to the correct web site.My mistake though, Tim. The modulating control valve is 120VAC. Sorry about the mix up.
Good Luck!
Ross

gerry gill

we stage fire

just about all our steam boilers Clammy.

It really makes the systems operate nicely.

I'd recommend you do it.

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Ross_7

Fuel usage

Gerry,
by doing this, how much of a reduction of gas usage for the steam system did you see? how often does it go to high fire on design day? TIA

jim_72

Clammy give Gerry Gill a call he is the axe on two stage firing. After he sets you up shoot me an e-mail and you can install a two stage in my Queens house. I've been looking for someone to do this since speaking to Gerry last winter.Peace Jay

gerry gill

depends

upon how big the boiler is Ross..if the boiler is sized dead nuts, it never builds up any pressure..if its say, the next size up, then it may go into low fire on a long morning run..how long it stays in low fire is strictly governed by how low the low fire setting actually is..we have some that once they go to low fire, they stay there..basically all weve done at that point is to remove the piping pickup factor once the pipes are hot..other systems we have jockeying back and forth between high fire and low fire..we go on a case by case basis and try to find the best way to steam for each particular system..no hard and fast rules here..some report fuel savings..some say the fuel use was about the same..but all say the systems heat more evenly..well sure they would..the high/low fire replicates the coal boiler the system was designed for..

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