Contact — Bolted Flange Joint Preload & Gasket Opening

Bolted high-pressure pipe flange joint: 8-bolt preload, internal fluid pressure separating force and contact sealing land compression.

Tolerance:

5%

Problem statement

Geometry

Two mating flange spools: bore R_in=45 mm, pipe outer R=60 mm, flange outer R=105 mm, thickness tf=24 mm, 8 bolt holes R=8 mm on bolt circle R_bc=84 mm. Contact mating face area A_gasket = 26666 mm2. Bolt preload F_bolt = -180 kN, internal fluid pressure p = 16 MPa (end separating force F_pressure = p * pi * R_in^2 = 1… show full text

Two mating flange spools: bore R_in=45 mm, pipe outer R=60 mm, flange outer R=105 mm, thickness tf=24 mm, 8 bolt holes R=8 mm on bolt circle R_bc=84 mm. Contact mating face area A_gasket = 26666 mm2. Bolt preload F_bolt = -180 kN, internal fluid pressure p = 16 MPa (end separating force F_pressure = p * pi * R_in^2 = 101.79 kN), external axial tension F_axial = 50 kN.

Material

Lower flange: ASTM A105 Forged Carbon Steel (E=200 GPa, nu=0.29). Upper flange: ASTM A182 F316 Stainless Steel (E=193 GPa, nu=0.30). Unilateral frictionless Mortar contact.

Boundary conditions

Fix lower pipe end (surface number 1). Lateral restraint on top pipe end (surface number 82 component=x, y). Internal fluid pressure 16 MPa on inner bore (surface number 2, 78). Bolt circle clamping force -180 kN on surface number 81. External axial tension +50 kN on surface number 82.

Measured quantity

Net residual sealing clamping force F_net = F_bolt - (F_pressure + F_axial) = 180 - 151.79 = 28.21 kN > 0 (prevents joint opening / separation; deviation <= 5%); mean gasket pre-compression pressure pc = 6.75 MPa under 180 kN preload.

WebCAE Terminal

units mm
material E=200000000000 nu=0.29 density=7850
import path="flange_joint_assembly_body1.step" format=step
material E=193000000000 nu=0.3 density=7980
import path="flange_joint_assembly_body2.step" format=step
contact frictionless
mesh tet size=7.5 order=2 bonding=0
fix surface number 1
fix surface number 82 component=x
fix surface number 82 component=y
load surface number 2 pressure=16000000
load surface number 78 pressure=16000000
load surface number 81 force=-180000 component=z
load surface number 82 force=50000 component=z
solve
minmax displacement_magnitude

Results comparison

Updated: 2026-10-19 · WebCAE solver