Thanks dan,
well scalar combination gives results which will never occur in piping as the scalar combination simply adds stress as numbers.
Take a simple case , when we add a spring to a system we simply add a force to system F=Kx or a constant force F (in case of constant sprinf)to reduce stress.What Caesar does is combines this spring force algebrically and gives the resultant stress and forces.So in this case if i am right it is algebraic combination.
Why cant the same be applied when we add a psv thrust force,which simply is a force.
I hope dan you got my point.
Regards