Re: F A I
Posted by Sylvan Tieger on April 13, 2004 at 16:22:25:
In response to Re: F A I
: How does one size a F A I and how many holes are required?

: Also is one required on storm water?

: Any and all information would be deeply appreciated

OK Arthur, this is going to be slightly technical so the ones who find technical stuff boring please move on.

This answer is for a UA apprentice mentality

Arthur, IF your using a comic book code like the SPC then here is the simpleton answer

Chapter 10 Traps

1002.6 Says NOTHING worth repeating total waste of ink and paper.

Now a real "plumbing code" states something to the effect

The F.A.I shall be half the diameter of the building house drain and in no case less then 3"

The F A I shall be located within 4 feet of the building house trap (up stream)

This F.A.I shall terminate at least 6" above outside grade.

The holes required would depend on the size and the actual size of the F A I and cover plate

The open end shall be protected by a perforated metal plate permanently fixed to the mouth of the inlet having a ventilating area at least equal to the area of the pipe OR you can use a return bend (180 degree fitting, prevents debris and or vandalism and full flow)

(The SPC piece of garbage that thinks its a a code says use a "screened outlet" )<<I wonder got paid off to allow this so called code to be used in a non third world country.

OK now for the number of holes for the cover plate SAME as an area drain cover opening

Lets assume we have a small min house drain of 4" dia and we know the F.AI. is half the size BUT no case less then 3"

The cover plate has 5/8 holes, so there would be 25 holes in this plate

If the cover plate has 1/2 holes it would require 36 etc.

PART two

Want to know WHERE the FAI AIR exits?

The colder air (6" above grade heavy air closer to the ground)) picks up heat within the building and it circulates taking the sewer "gases" out through the vent terminals.

The Vent terminals extend (if its a decent code) 24" above the roof IF this is a weather protection roof only and 7 FEET above roof level if it is a promenade type.

The vent terminal shall be (shall be means this is it in plumbing codes) 4" in diameter to prevent closure during the winter months as the warm vapor hitting the cold outside exposed piping can freeze (HOAR FROST) if this piping is less then 4" depending on climate and FUs usage.

Arthur there is a lot more to the vent terminal as far as locations by over hangs, adjoining buildings widows but that is another posting OR just E mail me.

See now imagine if you didn't have a real code to deal with this F A I would not even be considered neither would a house trap as many localities no longer use them.

Makes smoke testing a lot easier

By the way stomm systems do not require a FAI as they are not connected to a soil/waste system where various types of sewer gases are present.

FUN huh, WAIT till you hit your 5th year apprentice studies THEN you really have fun learning WHY

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