Pipe Calculations

BAB

The article was written several years ago but am I the first to notice a rather important typo?



“Balancing Steam Systems”

Using a Venting Capacity Chart

by Gerry Gill & Steve Pajek

© copyright 2005 Gerry Gill & Steve Pajek

 

On page #14 there is a chart with a typo.

 

     How Much Air Is In A Pipe ?

 

Cubic feet of air

Pipe Size                in each linear foot of pipe

 

1-1/4"                     .010

1-1/2"                    .014

2"                          .023

2-1/2"                    .030

3"                          .053

3-1/2"                     .07

4"                          .09

5"                          .014  >>>   (should it be .14 ?)

6"                          .2

8"                          .36

 

<strong>I came across some funny answers when I used

this chart to calculate air in 5” pipe</strong>

gerry gill

opps..

that would tend to alter the result a bit, huh..good catch.

MikeyB

Chart

My chart reads .14 cf for 5" pipe

BAB

original vs copy

Thanks for the reply.  The article has been very, very helpful. 

I downloaded my copy on 9/12/07.  The chart reads .014 for 5" pipe size, a definite typo.  Try downloading a fresh copy from the site like I did to see if it matches your originals.  Maybe someone noticed the typo before me & the website corrected the entry a year or so ago, .... great!



The only question I have is ideal placement the air eliminators?  I use Gorton #2 & #1.  My first installation of the Gortons was near the end of my main pipe headers, furthest from the boiler.  Recently I noticed that on my long pipe mains the majority of the pipe air volume is actually close to the boiler.  For example, 20 feet of 5" pipe and 3" pipe will have more trapped air to eliminate than 20 feet of 2' pipe.  In round numbers there is three times more air in the large pipe mains versus the smaller pipe mains.  I have therefore started to move some of my air vents (Gortons) from the end of the pipe runs to the start of the runs, closer to the boiler.



I have 5 steam mains each with its own respective thermostat & Honeywell motorized steam valve.  My longest main is about 200 feet long & caused me the most trouble.  It used to take 25-30 minutes for us to get steam.  After we got the steam it would rarely heat the radiators.  Now we get steam in in 10-15 minutes & the radiators really cook, all the way across their 14 foot lengh.. 

What is your advice on placementof the Gortons on the long, long pipe runs?