wht is the purpose of holes in man hole covers
wht is the purpose of holes in man hole covers
(OP)
what is the purpose of holes in manhole covers?
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wht is the purpose of holes in man hole covers
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RE: wht is the purpose of holes in man hole covers
RE: wht is the purpose of holes in man hole covers
"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.
http://waterhammer.hopout.com.au/
RE: wht is the purpose of holes in man hole covers
RE: wht is the purpose of holes in man hole covers
1. "At most, a ventilated cover may permit partial drying of the manhole but it cannot affect appreciably conditions in the pipe between manholes."
2. "In exceptional conditions where ventilation may be needed to relieve pressure differences or prevent oxygen depletion, special vents should be provided." (I believe Mr. stanier's application might fit this bill, and I think "special vents" in that context were probably meant to potentially refer to structures beyond simple cored or drilled holes in the cover.)
3. "On sanitary sewers, holes in the covers allow the undesirable entry of stormwater and grit, as well as the mischievous entry of sticks; and they favor the escape of sewer air, causing odor nuisances." (i.e. holes are likely to increase volume to be treated, particularly in low lying areas or areas subject to flooding etc., where alas many sewers are wont to be!)
For these reasons I believe modern trends are more likely to want tighter overall systems and manholes, including covers.
RE: wht is the purpose of holes in man hole covers
RE: wht is the purpose of holes in man hole covers
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: wht is the purpose of holes in man hole covers
Addenda:
In front of the old home place there is 12' diameter brick gravity sewer that comes from Birmingham, Alabama. The manholes are spaced quite close to gather as I could see three standing on sidewalk in front of the house. While walking to school one morning the air was still enough that you could get whiff of H2S as you passed by a manhole. That morning as I got to the one in the street in front of the school and about 15' from the manhole there was an explosion in the sewer line which lifted every cover in sight to way above he 50' telephone poles. The one by me came down through the telephone wires and took out about 1/3 of them. from that time on I avoided hanging around any sewer manholes.
RE: wht is the purpose of holes in man hole covers
The stack vents in the house laterals take care of the venting.
RE: wht is the purpose of holes in man hole covers
RE: wht is the purpose of holes in man hole covers
Note that gravity sewers do not operate with full pipes, there is air above the fluid.
Note that when you drive down a northern residential street in the winter, you can observe the venting and condenstation.
If you remain unconvinced, perhaps you should consider reviewing a book like Metcalf & Eddy's Collection & Pumping of Wastewater. The link contains a pertinent section discussing house venting.
RE: wht is the purpose of holes in man hole covers
Thanks Bimr for sharing a great stuff with all.
John ww.minidig gerhire.ie /#/skip-hi re-dublin/ 4547725214
http://w