where Δ(Pb) is the bolt force increase,
and Δ(Pg) is the gasket clamping force
decrease.
Action of axial force P leads
to bolt elongation increase Δ(δb) and
gasket contraction decrease Δ(δg),
which are equal one another (See
Fig. 2). The creep-relaxation of the
bolts and gasket due to prolonged
action of constant internal pressure p
and elevated temperature T will lead to
complete gasket compression loss
accompanied by joint opening and
leakage.