DW85745
Member
https://terrylove.com/forums/attachment.php?attachmentid=16470&d=1338214054
Terry: From the YES picture I think I see what you mean.
Let me confirm please.
The Wye is on it side with the 45 at the same level as the Wye outlet.
The "P" trap weir appears to be slightly above center line of the 45 in order to obtain the "1/4 to 1" required slope.
So I ASSUME I should consider the center line of 2 inch branch pipe to its top to be the vent area.
Using the - rule - that:
"The bottom of the pipe at the trap weir may Not be higher than the top of the pipe at the vent opening"
should keep one out of trouble.
So if I run a string line from the top of the branch pipe to the trap weir and make sure the bottom is not higher
than I should be OK ? Is this CORRECT ?
=============
COMMENT: I guess the code makes this presumption (example):
Using the wet vent from the lav with a San-Tee at its end and the vent located on top of the San-Tee, its easy to
see how the vertical pipe gets vented. However since the fixture arm slopes downward gas IMHO could collect there.
The code must ASSUME (??) the pipe will never be full with water, hence that any gas will escape from the fixture arm by the draft
of the vertical pipe pulling it out even though we have a downward slope.
Terry: From the YES picture I think I see what you mean.
Let me confirm please.
The Wye is on it side with the 45 at the same level as the Wye outlet.
The "P" trap weir appears to be slightly above center line of the 45 in order to obtain the "1/4 to 1" required slope.
So I ASSUME I should consider the center line of 2 inch branch pipe to its top to be the vent area.
Using the - rule - that:
"The bottom of the pipe at the trap weir may Not be higher than the top of the pipe at the vent opening"
should keep one out of trouble.
So if I run a string line from the top of the branch pipe to the trap weir and make sure the bottom is not higher
than I should be OK ? Is this CORRECT ?
=============
COMMENT: I guess the code makes this presumption (example):
Using the wet vent from the lav with a San-Tee at its end and the vent located on top of the San-Tee, its easy to
see how the vertical pipe gets vented. However since the fixture arm slopes downward gas IMHO could collect there.
The code must ASSUME (??) the pipe will never be full with water, hence that any gas will escape from the fixture arm by the draft
of the vertical pipe pulling it out even though we have a downward slope.
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