Steam Radiator Vent Problem

Alva Allen III - AA Mechanical Contractors

Started this thread while on vacation. When I got back, I lowered the system pressure from 3 psi to 2 psi max. Now the boiler cycles the burner on at 1.25 psi and off at 2 psi. What a difference!! System began to function like a dream for over 7 days. Now I am getting periodic failure of the steam air vents which I know are caused by the water being dirty.

2 Questions:

1. How do you recommend skimming the boiler?
2. How do you recommend cleaning a system that is 60
years old with no prior treatment that I know of?

Alva Allen III - AA Mechanical Contractors

Steam Air Vent Problem

I recently replaced the boiler in a old one-pipe system. Once I got the boiler on-line, I began to have water and steam spitting out of the air vents. I replaced the air vents, but several of the new ones are doing the same thing. Where should I begin troubleshooting this problem?

DanHolohan

Right here

Spitting vents

It pays to wander off the Wall.

Unknown

check a few things

If the water is bouncing in the glass heavy, the boiler needs skimming.

If the insulation is missing on the piping, the pipes are too small for the load, and the velocity of the steam will carry water with it.

The header and equalizer are all as the book says, height and diameter, and there are no bullhead tees, of course.

The radiation amount matches the boiler rating plate "sq ft EDR", or a little more.

The main air vent is at the right place for whichever steam or vapor system it is.

The radiator vents haven't failed.

The vents don't vent faster than they should on the radiators (velocity again).

The steam pressure as at about 1-2 PSI on a one piper.

And likely something else that I forgot......

Noel

Dave Yates (PAH)

Man, oh man

Have we seen that this past week! Nice article in SHT, BTW. Ours was the "doorway method" for a one-pipe turn-of-the-last-century system. 280,000 Btu in a 1,400 sq ft home! Actual conected load was less that 1/2 the rating.

I contacted Burnham to get the max de-rate allowable for this beauty. We re-piped the 2" running straight up into the old mains with the exact factory specs and added the 3" header/equalizer/& 3" connections to the 3" main.

The wet returns were replaced.

A vaporstat replaced the pressuretroll and, unfortunately, short cycles will be the norm from now until eternity. Very quiet now.

One problem remains: The 1" 90-degree-to-the-side-horizontal takeoff to a bathroom continues to collect water, which can be heard slogging its way back during the off cycles. There's no room to add a 45 degree angled take-off, so we're contemplating a downward slope with dripped end.

What connected load! Good grief, we could still heat the neighbor's home with the excess capacity.

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Boilerpro_3

Welcome to my world

Minimum oversize is about 60% water or steam. The "best" contractors doing steam in the area don't even measure radiation or pay any attention to factory recommended piping. Lots and lots of really bad Weil EG installs round here.

Boilerpro