How did it work?

lchmb

I removed this steamer for a friend. The only reason we did anything to the system was because of a small crack in the 3rd section. He's had no complaint's of banging or uneven heating.

As you can see from pic 2 there are two 90's about 10 feet down the main. The main pitche's down towards the 90 which then goes up. The main leading away from that point pitched back towards the 90's and when I broke it apart it was well flooded (not a nice bath)

So can someone explain to me why there was no banging? This of course was only one issue, they have a few and we'll be dealing with them all...

Kal Row

the anatomy of a bang is...

Fresh hot steam going out and cold return condensate coming back on the same line, the condensate explodes into steam on the spot against the top of the horizontal pipe, and that what you hear, but in your system the steam doesn’t get out until it has slowly cooked out the trapped condensate, and stays clear until the whole show cools – the regular return path for the condensate from the house must be good and going back into the boiler through the Hartford loop – so you system is silent – there are people that do dropped headers that trap lots of water upon cool down, but never bang for the same reason, “slow cookout”

Read “the lost art of steam heating” – you can get it here in the on-line store

lchmb

I have

Good thought Kal, and yes I have read the lost art (excellent and a must read) but here's a few thing's I forgot to mention (actually to tired to type). 1-the Hartford loop was actually two inch's higher than the water line. 2- the condensate line was gone, I mean rotted right through. So there was no water returning that way. And on the Hartford loop itself, which is supposed to be a close nipple was actually a 6" nipple, which in itself should have caused some banging at the end of cycle..
Just incredible some of the thing's we find that work, and shouldn't have....


It has been repiped properly and is incredibly silent, I just couldn't believe when the customer's told me that it never banged at all. Thank's for the thought's...guess it goes to show steam will do what it wants..

Unknown

Slow cookout?

I have never heard this analogy before. If the condensate collected at these low points which it did, then no steam could have got to the rads downstream of this point. Raising boiler pressure would make-it "plow-through" but initiate hammering. Drop headers are used to further dry the steam in lower ceiling heights providing a longer length for the steam to travel, and are graded accordingly to permit the piping to drain.
Steam constantly wants to revert back into condensate, so if there is a low point in the "road downstream" , how is it cooked-out unless it`s dripped?

Dave

Kal Row

2 things...

Steam doesn’t “want to” anything, it’s an intimate energy object – it’s temp will move from high to low, as will it’s pressure – with the latent heat equation added in, yes it condenses, but as it does, it gives up the latent heat, to the local pipe and water pool, faster than it can absorb it, and it will in turn vaporize it, to be sure this water absorbed tons of heat as it vaporizes (latent heat again – refrigeration cycle) but this initial steam is not as superheated dry steam as direct steam off the fire, so this initial plug of steam being cooler and wetter– wont flash water in it’s path as much, as from dropped headers being dry – I have seen “down and up” ones that have to be pooling water, beside there may be enough pressure to literally push through the few inches of water, and no, you don’t get banging unless it’s a little water at the bottom of a relatively horizontal pipe, where the latent heat of condensation instantly imparts way more heat than the water can hold – a lot of water however, takes away all the latent heat from the steam, and there is just a pressure equalization going on across it until enough latent is imparted to it to turn it into steam

Also to lcmb: even though you have no return, this, area is the return pool at the end of the cycle – and while it is quiet – it is definitely costing you BTUs big time