This document contains calculations for the trunnion support of a pipe. It provides input data on the pipe dimensions and material properties, as well as loading conditions. The calculations determine the linear loads, bending stresses, primary stresses, and combined stresses on the pipe. The results indicate that the circumferential stress of 163.03 MPa and longitudinal stress of 170.73 MPa exceed the allowable stress of 148.94 MPa, meaning the current trunnion design is inadequate for the given pipe and loading.
1. Trunnion Calculation Sheet
PIPE SUPPORT No.
LINE NUMBER.
PIPE INPUT DATA:
Pipe Dia. mm = 600 Pipe radius (R) mm = 300
Pipe nom. thk (Tnom) mm = 12.7 Pipe tolerance (%) = 12.5
or Pipe tolerance (mm) =
Pipe min. thk (T) mm= 7.93
Trunnion Dia (d) mm = 355.6 Trunnion radius (r) mm = 177.8
Pad nom. thk (tpnom) mm = 0 Pad tolerance (%) = 12.5
or Pad tolerance (mm) =
Pad min. thk. (tp) mm = 0.00
Moment arm (L) mm = 613 Pipe corr. allw. (mm) = 3.18
Effective wall thickness for calculation
(tmin) mm = T + tp = 7.93
LOADING INPUT DATA:
Design press. (P), barg = 15.17
Direct axial load (Fa), N = 38500
Force producing longitudinal moment (Fl), N = 17000
Force producing circumferential moment (Fc), N = 7000
0 - Original Issue 6/28/2008
Rev Revisions Date Drawn Chkd Appd
Drg No. Trunnion calc Sheet 1 of 2
partrunn page 1 6/28/2008 7:20 PM
2. Trunnion Calculation Sheet
PIPE SUPPORT No. 0
CALCULATION: (USING KELLOGS METHOD)
Longitudinal linear load (fl), N/mm = 104.92
Circumferential linear load (fc), N/mm = 43.20
Direct axial lineal load (fa), N/mm = 34.46
Combined circ. load with out-plane factor (f1), N/mm f1=1.5(fa+fc) = 116.49
Combined long. load with out-plane factor (f2), N/mm = 156.60
Circumferential bending stress (Sbc), N/mm² = = 105.66
Longitudinal bending stress (Sbl), N/mm² = = 142.05
Hoop primary stress (Sph), N/mm² = Sph=P*R/(10*tmin) = 57.37
Longt. primary stress (Spl), N/mm² = Spl=P*R/(20*tmin) = 28.69
Combined circ. stress (Sc), N/mm² = Sbc + Sph = 163.03 109%
Combined long. stress (Sl), N/mm² = Sbl + Spl = 170.73 115%
Allow. stress (Sh), N/mm² = 99.29 1.5 · Sh (Sha), N/mm² = 148.94
Sc to be less than 1.5 · Sh
Sl to be less than 1.5 · Sh
RESULTS:
This calculation shows the trunnion to be: INADEQUATE
0 - Original Issue 6/28/2008
Rev Revisions Date Drawn Chkd Appd
Drg No. Trunnion calc Sheet 2 of 2
f
F L
rl
l
=
π 2
f
F L
rc
c
=
π 2
f
F
ra
a
=
2 π
( )f fa l2 15= +. f
S
f R
t
bc =
117 1
3
2
.
min
S
f R
t
bl =
117 2
3
2
.
min
partrunn page 2 6/28/2008 7:20 PM
