bending stress in horizontal pressure vessel saddle base pla

huangyhg

bending stress in horizontal pressure vessel saddle base pla
i am looking for a correct formula for the bending stress in the saddle base plate of a horizontal pressure vessel.  the current formula i have has incorrect units.  
fb = [(6*m)/(tb^2)] is the formula i'm using (units of lb/in instead is lb/in^2), where fb = bending stress, m = bending moment, tb = base plate thickness.
i have limited access to references so i would appreciate any formula or online reference site anyone could provide.  
also, if this is the correct formula could someone explain to me why the units are not in psi.
your formula seems simply the elastic stress for bending of a rectangular section, which is obtained by dividing
m (ft x kip or in x kip) (which is moment)
by
(b x d^2)/6     (say in^3)
b is width of the rectangular plate and d is its depth against flexure (it seems, for your case, the thickness).
which is the elastic modulus of section for the outer fibers in a rectangular section,
this will give you stress in consistent units, be kip/in^2 or kgf/cm^2 and so on.
the stress you will compare to some allowable or limit stress.
i hope you have no doubt about what your moment for design is.