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FITTING PIPE INTO
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OPEN-WEB JOISTS
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GIVEN
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d
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pipe diameter
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in
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L
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joist spacing (center to center)
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ft
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D
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total depth of the joist
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in
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W
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width of the chord of the joist
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in
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h
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height of the chord of the joist
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in
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l
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total cut length of the pipe
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(Optional)
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ft
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PIPE RISE CONCEPT
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g
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length of opening (gap) between joists
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g = L - (W / 12)
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ft
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r
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slope of the pipe as it slips past joist
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r = (d + h) / g
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in / ft
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∆d
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total rise
of the pipe above bottom of joist, when slipping past joist
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Δd = l x r
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in
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∆o
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available
height for pipe to slip inside of top chord
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Δo = D - h
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in
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lm
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maximum length of pipe given joist
parameters
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lm ≤ (D - h) (L - W/12) /
(d + h)
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ft
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SIMPLIFIED FORMULA
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lm
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maximum length of pipe given joist
parameters
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lm ≤ (D2/3 + g2/3)3/2
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ft
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ED MILLER AFSA FORMULA
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lm
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maximum length of pipe given joist
parameters
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lm ≤ (D / 6) x L
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ft
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https://www.meyerfire.com/uploads/1/6/0/7/16072416/2527-v1-v600_orig.jpg
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