Steam article questions

Lyman

Does anyone remember Holohan's article in Plumbing and Mechanical that explains the speed at which steam at different pressures moves through pipes? It somehow equated the entire process down to VWs and school buses on an interestate. I have searched the archives but have been unable to locate anything. Any help would be appreciated.
Thanks,
Lyman

Steamhead (in transit)

I think this is in \"Lost Art\" too

basically, steam at higher pressures is more compressed so it takes up less space in the system. You need to keep generating more and more steam to fill the system as the pressures go up. Since high-pressure steam fills the system slower, it doesn't move thru the pipes as fast.

With steam at or close to atmospheric pressure, the steam is not compressed so it takes much less steam to fill the system. With proper air venting, low-presure steam moves faster thsn high-pressure steam with poor venting.

The key is venting the air properly. With good venting, you don't need to develop more than a few ounces pressure to make the steam move. That's all it takes to overcome the friction in those big pipes.

David Hohengasser

Vents on radiators

I know proper sized vents on mains is critical. Are there different size (volume) vents for the radiators? Should a hissing noise ever be heard? How do you determine size of vent, if avaialable?

michael_15

You should start a new thread

Since this is a new topic.

In short, though, yes, there are multiple radiator vent sizes (as well as adjustable versions) that can be found. Hissing is often an indication of an overly powerful boiler or lack of main vents.

If you post a picture of your vent (start a new thread), someone here can almost certainly tell you what type it is. If you're hearing hissing, I'd look into the main vent situation. Main vents are the vents on your mains (the big pipes typically in your basement).

-Michael

Christian Egli

My memory fails me

I distinctly remember that article. I always love reading Dan Holohan's columns.

It was in PM Magazine. However, I do not remeber the date. I would say it was within the last two years.

I did a little search on the PM site, in the feature items, and I found nothing.

The best thing to do is look back into the old stack of magazines...