12 Allowable Pipe Span Formulas and Tables

12Allowable Pipe Span Formulas and Tables Pipe-Span Stress Limits M 5 WL2 Sa=-= z 4Z In order to have a workable set of pipe-span tables or to find an allowable span that will require a minimum of manual calculations, the limit for dead load stresses is set at Sh/2. This eliminates the need for checking the sum of the longitudinal pressure stresses plus dead load stress. (Sh = allowable stress at maximum temperature, ASA Code B31.1 and B31.3.) The formula used to determine the maximum spans in the tables (Tables 12-1 through 12-9) is a mean between a uniformly loaded beam simply supported at both ends and a uniformly loaded beam with both ends fixed. This mean formula most nearly depicts the conditions actually existing in a refinery. (See Figure 12-1.) By inspection, if the two moment diagrams in Figure 12-1 are superimposed, the point of the maximum bending moment will still be at mid-span. or L Maximum allowable pipe deflection between supports must not exceed 1 in. or 1/2 the nominal pipe diameter. whichever is the smaller. This is the basic piping practice: however, it is subject to compliance with the customer's specification. The formula used to determine the deflections in Tables 12-1 through 12-9 is a mean between a uniformly loaded beam simply supported at both ends and a uniformly loaded beam with both ends fixed. (See Figure 12-2.) In order to maintain homogeneous units, " Lh must be in in. and "W" must be in lbs/ in ., however, for ease of handling we wish to have " L" in ft and "W" in lb/ft, which we must now convert to inch units. The preceding equation becomes: + -wu) (wu 8 24 A safety factor of 1.25 is required because of the discrepancy between theoretical assumption and the actual field situation. 5WU 48 In order to maintain homogeneous units, "L" must be in lb/in.; however, for ease of handling we wish to have " L" in feet and "W" in lb/ft, which we must now convert to inch units. Thus the preceding equation becomes: swv M = -48 = w Pipe-Span Deflection Limits Mean = M = 112 - wv 5 M=--X12 4 ~ ~0.8 Z f, "" 5WU 4 6 WL4 13.5WL4 = -- = 128EI EI 6 = 13.5WU EI (Text continued on page 320 314 Allowable Pipe Span Formulas and Tables Fixed Ends Simply Supported a~:=:~~~-L.~IIIII ~ ___. :___. . .,___~ - .~ Load -. .,.> _j_ !---~..,.....--- . . - - > ..LL.---~~--,.­ > L 2 Shear _j_ ,I Moment Fixed Ends Simply Supported V = WL V = WL 2 Mmax = 2 WL2 WL2 S 24 Figure 12-1 . Diagram showing how stress limits are determined by figuring the mean between a uniformly loaded beam supported at both ends and a uniformly loaded beam with both ends fixed . Fixed Ends Simply Supported ~ 1 = 5WL 4 .:12 = 384EI Mean: = ~1 + ~2 2 = WL4 384EI 3WL4 384EI Figure 12-2. Diagram showing how deflection limits are determined by figuring the mean between a uniformly loaded beam supported at both ends and a uniformly loaded beam with both ends fixed . 315 Piping Stress Handbook 316 Table 12-1 Piping Spans Based on the Following Carbon Steel Materials: Seamless A53 Gr. A, A106 Gr. A, API SL Gr. A; Welded A53 Gr. B, API SL Gr. B, A1 55 C55 Class 2 201"F-600"F with Commodity • (f, 6,175 psi) ;;, 200" F with Water, No Insulation (f, = 7,650 psi) Pipe Size 3/4" I 1-1 /2 " 2" 2' 3" 4" 6" B' 10" 10" 12" 12" i4' 14" .!.§' ! tl" 18 18" 20" SCH. 80 80 80 40 8U 40 40 40 40 20 _40 20 STD . JO STD. 10 SJ!J. 10 STD. 10 Maximum Span 17 ' - 6" 20 -0" 24 ' -0" 26' -0' 2~ -6" 31 -6. 34 -6" 4U - 6" 4~ - 0" 45 -0" 49 -6 47 - 0" !lZ -0" 47 -6" 53 -6' 48 -6' 5~' - 0 49 - 6" 5b - b' 50 -6" = Recommended Span Defl . 1-13 16"* 1- 131 '16"* 1-13, '16"* 1-3, I" * * 1-~ -3 4" * 1-4 '16" .. 1-l rz· * 1- '16" ... 8" * -- ( IJ' - 3 '16" - 1/4" * * * .. -1/4" * /8" -1/B" * 13/16" - 1/16" .. 3 4. 12' -0" 14 -6" 19' -0" 23 -0" 23'-0 27 -6' 31 -0" 3/ -0" 41 -6" 44 ' -0" 4l>' -:-0' 45 ' -6" 44 ' -0" 46 -b" 51 -0" 46 ' -6" Defl. 3/8" 1/ 2' l/4" I" 26'-6 29 -6" J5 - 0" 39 ' - 6" 39 ' -C 1" l" ~.· - j_ 40 -c 45 -6 1" 1" 1{8 1" .. 3/4" J 47 -6" 55 - 6" 47' -6 ' 14' -0" 15 -b' 19 -6" 21 - 0" E- 1 1" 53 ':'tl' Maximum Span 11 /1 6" 1" ~8 4!. Weight of Water, Minimum Insulation Recommended Span Defl. 7/8" * 7/8" * 1" 7/8' 11 ' -0" 13 -6 ' 18 -0' 20 -0" .. __£] 1" 1" / I!' '8" 8' jf~ 5 '8" 1 / 16" -b' ';)f.l!" 4b'-6" 42 -6" 48 -0' 43 - 6" 49 -6" ..'!_4 ' - 0' 3/4" 1/2" 3 ' 4' 1 ( 2" 5/ 8" l ' 2' - 25 ' -6" 27 -6' 33 -0" 39 -o· 36 ' -6" 40 -b' 56 -6 " 43 -0" 37 - 6" 44' -0" 38 ' -0" 45 -0" 39 -6' Defl. 3/8" 1/2 " 3/4' 3/ 4' / 8' 1/ 8" 3/ 4" 3/ 4" 7/B" 9/16" /16' 1/16' 11/16" 7/ 16" ~/ 8" 3/ 8" 9/16' 3/ 8" 4~--6 " 1!2'' 41'-D" 3/ 8" !I • Exceeds maximu m deflec tion. Courtesy of Power Piping Company. Table 12-2 Piping Spans Based on the Following Stainless Steel Pipe Materials: Seamless A3 12 TP316, A312 TP317, A430 FP316H , A376 TP317 201 " F-600° F with Commodity (f, = 8.550 PSI) ;;, 200"F wit h Water, No Insulation (f, 9,375 psl) = Pipe Size SCH. Maximum Span Defl. Recommended Span Defl. .. Maximum Span Weight o f Water, Minimum Insulation Recommended Span De fl. .. 1" .. * •.. • Exceeds maximum deflection . Courtesy of Power Piping Company. Defl . . 7/ 8" Allowable Pipe Span Formulas and Tables Table 12-3 Piping Spans Based on the Following Stainless Steel Pipe Materials: Seamless A213 TP304L, A312 TP304L, A376 TP304, A430 FP304H " 200" F with Water, No Insulation (f, = 7,650 psi) Pipe Size SCH. Maximum Span Defl. Recommended Span 201"F-600°F with Commodity (f, = 5,800 p si) Defl. Maximum Span Defl. Weight of Water, Minimum Insulation Recommended Span Defl. ----------~----------------~--------------------~--------------------~------------ 2-1!16" 2-1 /16' 1 12'-0" 14 1 -0" 14' -0 11 22 ' -6" 3/8" l/2 11 3/4" 1" 15'-0"11 3/4" * 7/8 11 * 20' -0" 13/16" 12'-6" l8 ' -6 7/B" * 15/16" 11 /16" 10' - 6" 13' -0" 17 1 -6" 14' - 0" 20' - 0" 21 I -6" 10" 12'' 12" 14 11 • Excee ds maximum deflection. Courtesy of Power Piping Company. Table 12-4 Piping Spans Based on the Following Stainless Steel Pipe Materials: Seamless A213 TP304L, A312 TP304L ~ 200"F with Water, No Insulation (f, = 7,650 p si) Pipe Size SCH. Maximum Span • Exceeds maximum deflection. Courtesy of Power Piping Company. Defl. 201"F-600°F w ith Commodity (f, = 4,500 psi) Recommended Span Defl. Maximum Span Weight of Water, Minimum Insulation Defl. Recommended Span Defl. 317 Piping Stress Handbook 318 Table 12-5 Piping Spans Based on the Following Nickel Pipe Material: Seamless B161 Annealed i!:200"F with Water, No Insulation (1, 4 ,000 psi) 201"F-450 "F with Co mmodity • (f, • 1,000 psi) = Pipe Size 3/4" 1" 1-1 /2" z 2 3" 4" b'' 8" 10" 10" 12' 12" 14" _li'' 1b' 16" 18" _II!" 20' 20" 24" £4' 30" SCH. 80 80 80 40 80 40 '10 40 40 20 40 20 Maximum Span 12 '-0" 13 -6" 6 -0" 17 -b' 18 -0" 21 -6" 2~ STD 10 10 STD 10 :SID 10 20 10 2L 55 10'0" 12 -6" 15 -6" lb' -b' 16 -6" 1/2" 1/2" 1/2" 1/Z' /2" '2" ~~· -IJ' I(>" 28' -0" 3 -6" 3 -6" 34 -b' 32 -b' .. 31 16' /8" 5 '16" -, j, __:,_1_0 Recommended Span Defl. -- _3 }" 3• 33'-6" !::>' - o· _39' -6" 35' -b" 40'-6" 36'-6" _42_ -_u· 37 -6" -b' _2_2 -0 2b' ~o· 29' -6" 29' - 6" _3~ -b' 3 1 ~o· 34 - 6" 31 -6" ~:,· - 6 32 -6' 36'-6" 33' - 0" _38 -0 34' ~o · 39' - 0 35' -0" 40' -0 Jb ' - 0. r'_l!'' lb" /8" 3/8" ~· 4 16" 4" 'I(>" /4" 5/16" 3.'16" /4' 3/16" Maximum Span Deft. 3 8" 1.'2" 1.12" ljZ_ 112" '2" lb' ' I(>' 8" 5/16" ~{8' !l/lb' 3, 8" 5/16" _318 1/4" 5 '16" 1 14" ' If) 114' 5/16' 3/16" '4' 3/ l b' 10'-0" 12 -0" 15 - 0" _16 ~o· 17 -0" 20' -o· 2J' -0 21 -0" 37'-0" 38'-0" 33 -o· 31 -!)' 35 ' -0" 32 -0" !b' -0' 33' -o· 17 -6' 34' -0" ;sa -6' 34' ~6' 39 ' -6" 35 -6" 4• - 37 -0" Weight of Water, Minimum Insulation Recommended Span Dell. 9' - 6" 11 - 6. _14 - 0" 1:, -o· 16 -0" ·~ -6' 22 :U" 26 -o• 28 -0' 28 -0' 3 1 - o" 29 - 0" 33 ' - 0' 30 -0" 34 -()' 31 -0" 35 - 6" J2 -0" 37 -ll' 33 -o· 38 - 0" 34 - 0" 39 ' - o· 35' -o· 3/8" 3/8' 7/16 lf8' 7!16" lb' I~ 3/ B' 3/8" 5/16" 3/B' _I 14' 318 " 14" ' 16 14" '16 " 1.14" :l/ 1b' 114' 114" 3 '16" 14' 16" De fl. 3/8" 3/8" If 6" 6" 16" 6' 8" 3 8' 5/16" 3 8' I ' 4" 3 8" 1 14 ' ' 16' 1 14" 5 '16" 1 14 .. ' If>' lf4' 1 14 .. 3 16" 14'' 1b" Courtesy of Power Piping Company. Table 12-6 Piping Spans Based on the Following Aluminum Pipe Material: Seamless B241 Gr. 3003 H112 <: 200"F with Water, No Insulation (f, .. 4,000 psi) Pipe Size 3/ 4" 1 1-1 /2" 2 3" 4" 6'' 8" IU' 10 12" 12" 12'-0" 13 -0" 15' -6" 7 16" 11 ' - 0" 16" /8" 15'~' 5 ' I(>' 18" ~ '16" lb' ' 4" 14" lb' 14" 1 'll' 3 16 1 18" 6" 13' -0" 15' -0" 15' -o· 16' -6' 18' -6" 80 80 !0 I{)_ 17 -0" 18 -6" 2u· - u· 23 -o· 25' -0" 0 40 40 40 20 40 20 STO IU 14" 16" b' STO I_!!' () 8" 20" 20" 10 24" 30 II Recommended Span Maximum Span 1_4' 24" Dell. SCH. ~ IU TD TO l 10 20 5S 201 "F-400"F with Commodity = Weight of Water, Minimum Insulation (f, = 1,750 psi) 23'~ 27 -0" 24 · -o· 28 -0' 24' -0" 8 -6" ~~~ ' - 8 -(>' ~4 ' -6" 29 -0" Z:> -b' 29 -(>' 25' -0" _29 -6" 25 I -0II Courtesy of Power Piping Company. .~ 18" Ill' zu·- 3 8" 7.'16" 3/8" :,/If>" 3/8" 5 '16" lb' 22 -0" 24' -0" zz_ -6 25' -0" 23' -0" 25 -U" 23' - 0" z Maximum Span Dell. - 2 2!l 23 ~5 - 0" 114" 1 14" '!_b_' 1/4" 1 13" 18 liB" 8 Ill' '16" 18" ~~~ · - 8 ' 16" 118" • ~5 6' -6" 8 -0" 10 - 0" 10 ' -b" 11 -6" 13 -0" 14 -b' II' -0' 18 -6" J7 -b' 20 ' - 6" 18' -0" 21 -u· 18'-0" -6" -b' :_1)_" -0" 25 -0" I 24 -0 • 6" /8" II 1/8" I 8" 118" I 8 1 18" Ill' Ill' I 8 16" 6 16" 16" ' lb" '16" ~0" -6" 22'-0" ~~· ~4 Dell. -u· _2_2_' ~· 19' -0' 23'-0" 19 I -6 II 5" 6" b' ,fl" 6' '16" 1/16 II Recommended Span 6'-6" 7 -6" 9 ' -6" 10' -u· 1 -0" 3 -0" 14' -u· 16 -0 17 -6" 1b' -b' 19 -6' 17 -0" 2ll 17 -0" 0 -6" -b' ~I -0 I B ' -0" 21 -6" Ill ~· - 18 - (}''_ 22' -0' 18 I -6 II Dell. 1 8" I 18 " 1 18" 8" 1 18' 1 8' Ill' r'_l!'' '16' '16" 1 16" '16" 16" I ' l b' '16' lb' II_(>' I ' lb' '16" '16" lb' ')_(>' 16" II Allowable Pipe Span Formulas and Tables Table 12-7 Piping Spans Based on the Following Aluminum Pipe Material: Seamless 8241 Gr. 6061 T6 201 ' F-400"F with Commodity :a Weight of Water, Minimum Insulation (f, = 2,000 p si) ;;. 200"F with Water, No Insulation (f, = 3,000 p si) Pipe Size SCH. Maximum Span Recommended Span Defl. Defl. Maximum Span Recommended Span Defl. 9'-6" 3/4" 3 8" 1/ .. 11' -6" 14' -0 11 14' -0" 18' -6" 20' -6" 24'-0" 3" Defl. 1!2" 7/ l6" l/2" 1/2" 7/16" 3/8" 1/4" 3/8' 1 8" 1011 10" ~~:: • Exceeds maximum deflection. Courtesy of Power Piping Company. Table 12·8 Piping Spans Based on the Following Aluminum Pipe Materials: Seamless 8210, 8234, and 8235 Gr. 6061 T4, 8241 Gr. 3003 H18 « 200" F with Water, No Insulation 201"F-600"F with Commodity (f, 2 950 psi) (f, = 4,500 psi) Pipe Size 3/4" 1" J-1/2" 2:: 3" 4" SCH. 80 80 ~~ 40 40 40 40 2o 40 20 STD nolO Maximum Span 17'-0" 19'-0" n::~:: 26 -6" 1 28'-6" 32 1 -6" 35'-6" 33:-0" 38 -6" 33 1 -6"11 39 ' -6 34'-6" ~~: =~:: Defl. Recommended Span Defl. 1-3/4" * 1-3/4" * 3/8" 1/2" 9'-0" 11'-0 11 n:=z:: 15 ' -6 11 18' -0" 20'-0" 23'-6 11 25' -0 11 l-1/4" * 1-3/16"* 1" 15/16" 9/1611 3/4 1/2 " Maximum Span ~~: =~:: 24'-6" 28'-6" 24'-6" 11 ~k~:: = Weight of Water, Minimum Insu lation Recommended Span Defl. 5/16" 3/8" s·-6" 7/16" 3/S" 5/16" 14'-6" 17 ' -0" 19' -0 11 22'-0" 23'-6" 3/16" 174" 3/16 11 23'-011 27'-0 11 25'-0" ~~a:: 3;8" 5/16'' m~ . m~~~ 10' -6" g:=~:: ~2:-f 6II g:=z:: 20 1::4'' 24" 20 30" ~s - 41'-6" 35'-0" _11_<:: -0" 3~' - b' ' Exceeds maximum deflection. Courtesy of Power Piping Company. 5/ 16" 3/8" 7!16" 5/16" 7/16" 3/ 8" 3;8" 5!16" 5/16" ~/4 " /16" 3/16" 1/ 4" 1/2" 1/4 11 3/16" / 4" -6 20 11 Defl. 1/ 8" - 7/l!)' 40'-0" 33 '-6" 'I_D -0" 1/4" 33 ' -Q' 1/2 11 ~/lb' 3/B"3/16" 3/8 1/8 30'-6" 26 -0" 31 -0 26 -b' 3 16" 8" 3 16" l I (8" 28'-0" 24 -0" 28 ' -0" l4 -b' 3/1 6" 1/B" 3/16" _1/8' 319 320 Piping Stress Handbook Table 12-9 Piping Spans Based on the Following Red Brass Pipe Material: Seamless 8 43 201"F-600"F with Commodity = Weight of Water, Minimum Insulation (f, 4,000 psi) ~ 200" F with Water, No Insulation (f, = 1,500 psi) Pipe Size 1 2" SCH. 2 ST!Y l ~' 14" 16" T6" 18' 18 £0" 20 24 II 24 30" 11 STO 10 s 10 STD lU 20 10 20 5$ Maximum Span --0. 36 -6" 33 -6' 37 -6" 34 -6' 38 -b' 35 ' -0" 39 -6' 3~ - 6 40 6" 36 I -6 II 1 42 1 -0"11 37 -6 Defl. 71 I 1/2" 3/8" 1/2 3/8' 7/16" 5/16 7/16" 5/16" 3/8' 1/4 II 3/8 11 1/411 = Recommended Span Maximum Span Defl. - - 1 -0 34 - 6" 31 - 6" 112" 3, 8" 1 - 611 17 - 6 16 - 0' :t~ -~· ICl 1!1 - 32 - 6" 32 -6" 33 38 - 0" 36 -0 39 :__U' 35 I -0II 40 I -011 36 1 -011 I 3 8" 7 ' 16" ~'Jil'' 7,' 16 5,' 16" 3 8" 1/4 II 3/8 11 1/4 11 - 6 J Jb' 1 '16" ib' 1b -6' 18 - 6" 17' -0" I~ Recommended Span Defl. -0 ' 16" 1!1 -U" '16' 16 -0" '!ll 18 1 -6" 17 -0" -6" ~ '!6 17 -0" 1!1'_ :Q_" 17 I -6 II 20 1 -6" . _!_!)_~ 1~ -0' _1_!1 -b' Defl. 6" 16" 1/16" 1 '16" -, T6" '16' '16" Hi,_ ' 16" 1 16 ' J b -6' II 19 -0" 17 I -0II Hl6' ~ 1/16 II l/16" 1/16" 20 1 -0" 17 1 -6 11 1/ 16" 1/16" Courtesy of Power Piping Company. where Ss = Longitudinal bending stress, psi = Maximum deflection, in. w = Weight of pipe, including commodity and insulation if any, lb/ft L = Length of span, ft E = Hot modulus of elasticity of pipe, psi I = Moment of inertia of pipe, in.4 z = Section modulus of pipe, in. 3 fs = Unit stress = Sh/2, psi . Sh per ASA Code B31.3 To solve for an allowable pipe span with a known deflection, use the following formula: L=~ Piping Wind Loads Wind Loads Tables 12-10 through 12-12 can be used to calculate wind loads. The wind pressure (P) in lb/ft2 on a flat surface normal to the direction the wind for any given velocity (V) in miles/hr is given quite accurately by the formula P = 0.004V2 Table 12-11 gives the pressure per square foot on a flat surface normal to the direction of the wind for different velocities as calculated by the preceding formula. The design wind pressure at the location of a given pipeline should be applied to the projected area of the out- Allowable Pipe Span Formulas and Tables side of the pipe (or insulation) to determine a uniformly distributed load as follows: W = (P) (Cs) (D) 144 where P = D = c. W Design wind pressure, lb/ft2 Shape factor (See Table 12-12) Outside diameter of pipe (or insulation), in. Wind load (lb/in) pounds per linear foot of pipe The design wind pressure depends on the location of the vessel or stack. The U .S.A. Standard Building Code Requirements for Minimum Design Loads, in Buildings and Other Structures, A58.1-1972, and the Uniform Building Code include a table showing wind pressure at various heights, and a map where these values apply. More tables have been developed according to wind velocity in miles/hr, wind pressure lb/ft2 , with reference to a pipe outside diameter. These tables are very useful for computer data input to model uniform wind load on piping. Table 12-12 Shape Factors Table 12-10 Official Designations of Winds Designation Miles per Hour Calm Light wind Gentle wind Moderate wind Fresh wind Strong wind Gale Whole gale Hurricane Less than 1 l to 7 8 to 12 13 to 18 19 to 24 25 to 38 39 to 54 55 to 75 Above 75 Surface General Use Cylinder Towers, stacks, drums, tanks, exchangers, piping, etc. Piers for towers and drums Tanks Open signs Solid signs Closed buildings, framing, and com. parts Frames, open-type structure Octagon Sphere Flat Prism * Beaufort Wind Scale, U.S. Weather Bureau. Table 12-11 Pressure per Sq Ft on a Flat Surface Normal to the Direction of the Wind Velocity (miles/hr! Pressure (lb/ft2) Corresponding To 10 20 30 40 50 60 80 100 0 .4 1.6 3.6 6.4 10.0 14.4 25.6 40.0 Gentle wind Fresh wind Strong wind Gale Gale Whole gale Hurricane Violent hurricanes 321 Shape Factor 0.6 0.80 0.60 1.60 1.40 1.30 1.60 Open plan 0.80 Sec. plan 0.00 Other plan 322 Piping Stress Handbook Table 12-13 Wind Load (lb/in.) 15 20 25 30 35 40 45 50 55 61 71 80 86 93 100 106 112 117 2.375 .14 .19 . 24 .29 .H .39 .4 4 . 49 . 54 3.50 .21 . 29 .36 • 43 .Sl .58 .65 • 72 .eo 4.00 .25 .33 .41 .so .58 .66 .74 .83 .91 . 37 • 46 • 56 .65 • 75 • 84 . 93 1.03 Pressi lb/ft Wind Velocity Hiles/ RR 4.500 5.563 .46 . 57 . 69 .81 .92 1.04 1.15 1 . 27 6 . 625 .41 .55 . 68 .82 • 96 1.10 1.23 1.38 1.51 8.625 . 53 .71 . 89 1.07 1.25 1.44 1.61 1. 79 1.97 10.750 .67 . 89 1.11 1.34 1. 56 l . 79 2.01 2.39 1.46 12.7 50 • 7 9 1.06 1.32 1.59 1.85 2 . 12 1.38 2.65 2. 92 14 .87 1.16 1.45 l. 75 2. 04 2 . 33 2.61 2. 91 3.20 2 . 99 3 . 33 3.66 4.12 16 1.00 1.33 1.66 2.00 2.33 2.67 18 1.12 1.49 1.87 2 . 25 2.62 3 .00 3.36 3.74 20 1.25 1.66 2.08 2.50 2 . 91 3. 34 3. 74 4 . 16 4.58 22 1.37 1. 83 2.28 2.75 3 . 20 3.67 4.11 4 . 58 5 . 04 24 1.50 1.99 2.49 3.00 3 . 45 4 . 00 4.48 4 .99 5.45 26 1.62 2.16 2.70 3.25 3.79 4.34 4.86 5.45 5.95 6.41 28 1. 75 2.33 2.91 3.50 4.08 4 .67 5.23 5. 83 30 1.87 2.49 3.12 3. 75 4 .37 5.01 5.61 6.25 6 . 87 32 2.00 2.66 3.32 4.00 4. 66 5.34 5.98 6.66 7.33 34 2. 12 2.83 3 . 53 4.25 4.95 5 . 67 6.35 7.08 7.78 36 2.25 2.99 3.74 4.50 5 . 24 6.01 6 . 73 7 . 49 8.24 38 2.37 3.16 3.95 4. 75 5.54 6.34 7.10 7 .91 8 . 70 40 2.50 3.33 4.16 5.00 5.83 6.68 7. 48 8. 33 9 .16 42 2.62 3.49 4. 36 5 . 25 6.12 7.01 7.85 8.74 9.62 44 2 . 75 3.66 4 .57 5.5 0 6.41 7.34 8.22 9.16 10.08 46 2.87 3.83 4.78 5.75 6.70 7,68 8 . 60 9.58 10 . 53 9.99 10.99 48 3.00 3 .99 4.99 6.00 6.99 8 . 01 8.97 50 3 .12 4.16 5.20 6.25 7.29 8 . 35 9 . 35 10 . 41 11 . 45 52 3.25 4.33 5.40 6.50 7.58 8.68 9.72 10 . 83 11 . 91 54 3 . 37 4.49 5.61 6 . 75 7.87 9.01 10 . 09 11.24 12.37 56 3.50 4 . 66 5.82 7.00 8 . 16 9 . 35 10.47 11 . 66 12 . 82 58 3 . 62 4.83 6 . 03 7 .25 8 . 45 9.68 10 . 84 12. 08 1 3.28 60 3.75 4.99 6.24 7.50 8 . 74 10.02 11 . 22 12.49 13.74 62 3 . 87 5.16 6.44 7.75 9.03 10 .3 5 11.59 12. 91 14.20 64 4 . 00 5.33 6.65 .008 9.33 10.68 11.96 13.33 14.66 66 4.12 5.49 6 . 86 8.25 9 . 62 11.02 12 .34 13.74 ' 15 .12 Allowable Pipe Span Formulas and Tables Table 12-13 Uniform Wind Loads (lb/in.) r~n~~ Wind Velocity Miles/ HR 60 65 70 75 80 85 90 95 100 122 127 132 137 141 146 150 154 158 2.375 . 59 .64 .69 .7 4 • 79 .84 .89 . 94 . 98 3. 50 • 87 .94 1.02 1.09 1.16 1.23 1.31 1.38 1.45 4 . 00 1.00 1.08 1.16 1.25 1.33 1.41 1.50 1.58 1.66 4.500 1.12 1.21 1.31 1.40 1.49 1.59 1.68 1. 78 1.87 6.525 1.65 1. 79 1.93 2 .07 2.20 2.34 2.48 2.62 2. 76 a: 8.625 2.15 2 . 33 2.51 2.69 2.87 3.05 3.32 3.41 3.59 "'....X 10.750 2.68 2.91 3.13 3.35 3.58 3 . so 4.03 4.25 4.47 12 .70 3.18 3.45 3 .71 3.99 4.24 4.51 4.78 5 . 02 5.31 "' 14 3.50 3. 79 4.08 4.37 .4 .66 4 . 95 5.25 5.54 5.83 ~ "' Q Q ~ 0 ."'"' "' 16 4. 00 4.33 4.66 5.00 5.33 5 .66 6.00 ~.33 6.66 18 4. 50 4.87 5.25 5 .6 2 5 . 99 6.37 6.75 7.12 7.50 20 5.00 5.41 5.83 6.25 6 .66 7.08 7.50 7.91 8.33 22 5.50 5.95 6.41 6.87 7.33 1. 79 8.25 8. 70 9.16 24 6 . 00 6.49 7.00 7 . 50 7.99 8.49 9.00 9 . 49 10.00 26 6.50 7 . 048 7.54 8 . 12 8.66 9 . 20 9.75 10.29 10 . 83 11.66 28 7.00 7.58 8.16 8.75 9 .33 9.91 10.50 11 . 08 30 7.50 8.12 8. 75 9.37 9.99 10.62 11.25 11.87 12. 50 32 8 .oo 8.66 9.33 10 .00 10.66 11.33 12.00 12.66 13.33 34 8.50 9.20 9.91 10.62 11.33 12.03 12.75 13.45 14.16 36 9.00 9 . 74 10.50 11.25 11 . 99 12 .74 13 .5 14.24 15 . 00 39 9.50 10.29 11.08 11.87 12.66 13.45 14.25 15.04 15.83 40 10 .0 10.83 11.66 12.50 1 3.3 14.1 14 .oo 15.83 16 . 66 42 10.5 11.37 12.25 13 . 1 2 13.99 14 .87 15.75 16.62 17 .so 44 11.0 11.91 12.83 1 3.75 14.66 15.58 16.5 17.41 18.33 46 u .s 12.45 13.41 14.37 15.33 15.28 17.25 18.20 19.16 45 12 . 0 12 . 994 14.00 15 . 00 15.99 16.99 18 . 00 18.99 20.00 50 12 . 5 13.54 14.58 15.62 16 . 66 17.70 18.75 19.79 20.83 52 13.0 14.08 15 .16 16 .2 5 17.33 18.41 19.50 20.58 21 .66 54 13 .5 14 . 62 15.75 16.87 17.99 19.12 20.25 21.37 22.50 56 14 . 0 15.16 16.33 17.50 18 . 66 19.82 21.00 22 .16 23.22 58 14.5 15.70 16.91 18 . 12 19 . 33 20 .53 21.75 22.95 24.16 60 15 . 0 16.24 17.50 18 . 75 19.99 21 . 24 22.50 23.74 25.00 62 15.5 16.78 18.08 19.37 20.66 21.95 23 .25 24.53 25 . 83 64 16.0 17.33 18.66 20 .00 21.33 22 . 66 24.00 25.33 26 . 66 17.87 19 .25 20.62 21.99 23.27 24 . 75 26.12 27 .50 66 15.5 323