Laserfiche WebLink
<br />I <br />J <br />1 <br />I <br />J <br />J <br />) <br />J <br />J <br />J <br />J <br />J <br />J <br />J <br />J <br />J <br />J <br />J <br /> <br />Plugged tees and crosses in a straight run do not require restraint. For restrained joints. <br />the number of feet of tied pipe required sha1I be in accordance with the following table: <br /> <br />TABLE OF RESTRAINED OR TIED PIPE REQUIRED ON EACH SIDE OF THE BEND <br /> <br />Note: (1) Table based on sand excavation for silt increase 500.4 <br />(2) Jf polyethylene wrapping is used. increase value by 100% <br />NR = Not Recommended <br /> <br /> 4' COVER 6' COVER S' COVER <br /> Bend Sizes by Degrees Bend Sizes by Degrees Bend Sizes by Degrees <br />Pipe 22.5 45 67.5 90 22.5 45 . 67.5 90 22.5 45 67.5 90 <br />size <br />3- NR NR NR NR l' 3' 4' S' l' 2' 3' 4' <br />4- NR NR NR NR 2' 4' 5' 13' 1 ' 3' 4' 5' <br />6- NR NR NR NR 3' 6' S' 9' 2' 4' 5' 6' <br />S- NR NR ; NR NR 4' 7' 9' 11' 3' 5' 7' 9' <br />lr NR NR NR NR 6' 10' 14' 17' 5' 8' 10' 12' <br />16- NR NRI NR NR 7' 13' IS' 21' 6' 10' 14' 17' <br />20. 12' 22' 30' 37' 9' IS' 22' 27' 7' 12' 17' 20' <br />24- 14' 25' 37' 43' 10' 18' 26' 30' NR NR NR NR <br />30- 17' 30' 45' 52' 12' 21' 30' 37' NR NR NR NR <br />36- 19' 35' SO' 61' 14' 25' 35' 43' NR NR NR NR <br />4r 22' 39'. 56' 69' 16' 2S' 40' 49' NR NR NR NR <br />4S- 24' 43' 63' 77' IS' 31' 45' 55' NR NR NR NR <br /> <br />The table was determined ftom the following fonnula printed in the 1975 fall issue of <br />.Cast Iron Pipe News. published by the Cast Iron Research Association. <br /> <br />L (restrained ~ength) = StKP A <br />. KFs+DPp <br /> <br />Sf = Safety factor (1.25) <br />P = Max. Pressure (150 p.s.e.) <br />A = Pipe Cross-section area (m. sq.) <br />Fs = Conduit fiictional resistance <br /> . neglecting bell resistance (p.l.f.) <br />D = Conduit outside diameter (ft.) <br />Pp = Passive soil pressure (p.s.f.) <br />K = 4 tan (fiiction angle) <br /> 2 <br /> 300-13 <br />