Boiler feed pump

RJ_4

Installing boiler feed pump on 1 pipe system, how close does pump need to be to Peerless boiler. have 5 dry vertical returns currently connected to a header which ties into boiler return line. Would like to install pump around corner from boiler ,about 15 ft. return lines are 1-1/4 what size should main return to boiler feed tank be ?. what size pump discharge line. Boiler is 211-A-07  tank is Hoffman Duplex 50 gallon.

nicholas bonham-carter

feed pump

what's wrong with keeping it a  gravity return?--nbc

RJ_4

feed pump

The old boiler held more water than the newer Peerless, that is why we went with the feed pump.

gerry gill

Why not a passive

reservior tank..less expensive..no moving parts..not pump controller..gravity doesn't fail.

nicholas bonham-carter

reservoir tank

gravity plus a couple of reservoir tank worked like a charm for me. here is cut and paste from an earlier thread:my reservoir tanksi put 2 old 15 gal. expansion tanks in my system. their horizontal centerline is 1.5 in. below the boiler waterline, measured from the floor, so as to best use the limited band of extra water that can be used by the boiler. the top of each tank is connected with a 1 in pipe from a tee at the top of the equalizer, to give sytem pressure to the surface of the tank waterline. the bottom of each is piped with a .75 in pipe swing joint to the wet return, so i can adjust the height if needed. each tank has .75 in. vertical nipples welded to the outer edge, and these have threaded rods running down to the floor. they are thus adjustable for height, if needed. this extra water supply will compensate for that time the burner cuts out on pressure, and the steam bubbles collapse, leaving the boiler low on water for a few minutes. the advantage over a pumped system is that it cannot overfill the boiler. now it seems to work. the system is a peerless 211a 1,050,000 btu. many thanks to gerry gill for showing pix of one he did recently, so i had more faith in this method of water compensation.--nbc [url=http://www.heatinghelp.com/forum-thread/122013/weil-mclain-reservoir-piping]http://www.heatinghelp.com/forum-thread/122013/weil-mclain-reservoir-piping

RJ_4

feed pump

Thanks for the detailed info.  Engineer spec-d feed pump , equip. already ordered

nicholas bonham-carter

who to call at 2 AM?

that brings up an interesting question: who to call at night about any heat problems-the engineer or installer?

how easy is it in a case like this to get the engineer to listen to the voice of experience, as opposed to hastily read specifications from catalog of the manufacturer of some gadget? remember all those "steam dryers" we have seen pictures of on badly installed supply pipes. those were the 200 MPG carburator of the steam world!--nbc

Jean-David Beyer

Who to call...

I do not think I overinsulated my house, but if my boiler quit at 2 AM, then unless it was leaking badly, I would just turn it off and call during normal business hours. It probably went down to 50F outside last night, and it was 73F this morning anyway. It did not heat yesterday either. If it was leaking badly, I would turn off the supply water if it was on, and possibly close the valves to the house.



As far as steam dryers are concerned, I do not know what they are in relation to home heating systems. On steam locomotives, they are called superheaters. They were originally called steam dryers, but when their true function was understood, they were renamed superheaters. The boilers on those machines are mainly firetube boilers, but the steam coming out of them goes through hairpins right down the flues to heat the steam well over the boiling point of the water (that is already quite high at 225 to 300 psi frequently used). The reason for that is that, except for starting, they just put a puff of steam into the cylinder and let it expand to push the piston down the cylinder. If the steam were not hot enough, it would start condensing in there and act as a brake instead of an accelerator. I suppose if the steam coming out of a home heating boiler is not hot enough, there could be a lot of condensation in the supply pipes wasting heat. But as long as the steam is hot enough to get to the radiators without too much condensation along the way, I do not know why they would need "steam dryers."

Jamie Hall

The steam dryers

to which we are referring here are an amazing array of doodads, mostly patented and sold at considerable price, which are alleged to remove the carried over water from a residential (or smaller commercial) boiler which was piped, not to put to fine a point on it, wrong.  There is no need for them in a properly piped installation.  Residential and commercial heating boilers, to my knowledge, never used superheat, which involves taking hopefully already dry steam (in a steam locomotive, from the steam dome, in a power boiler, from the steam drum) and running it through additional heating.  In locomotive boilers this is done with tubes in the flue passages (fire tube boilers); in power boilers, it is simply additional tube banks, usually in the flue passages from the main fire box.  The purpose is to shift the temperature and pressure away -- usually significantly away -- from the condensation point of the steam.  It also extracts additional thermal energy from the exhaust heat.  Superheated steam can be used expansively, without running any risk of condensation; in a steam locomotive, as noted, this means you can set the cutoff quite short and save a lot of steam and fuel.  In power applications, it means your high pressure turbines can have a considerable pressure drop across them without condensing.

But don't confuse superheaters -- even with the old old name of steam dryers -- with 'steam dryers' sold for heating applications!

Jamie Hall

I might add...

at the risk of confusing all and sundry...

That saturated steam, which is at the combination of temperature and pressure at which it will condense if energy is removed, is sometimes referred to as wet steam.  This is not the same thing at all as steam with carried over water droplets entrained (although if there is carried over water, the steam will be saturated...).  Entrained water is what can be avoided by proper near boiler piping, and should be.

To which it might be added that anything which removes energy from a saturated steam flow -- such as poorly insulated mains, or reduced throat valves, or a several other things -- will not cause entrained water droplets, but will cause condensation of some of the steam.  Which not only is inefficient, but can cause water hammer.

To which might also be added that entrained water in power applications -- such as from foaming in a locomotive boiler -- can raise all kinds of havoc in the attached turbine or piston engine, and thus is to be avoided... (you wouldn't believe until you see it what entrained water droplets will do to a steam turbine!)

Jean-David Beyer

condensing

I would believe. If too much steam condenses in a steam locomotive cylinder, the thing will crack or explode, depending how much water is in there. Steam is compressable, but water is not. And since the locomotive will not stop on  a dime, the piston will go all the way to the end, and if you are lucky, you will just get a large repair bill.



I do not know what would happen in a steam turbine. I guess the blades would not wear out as fast as if sand were blown in there, but it would not be a good thing.