Please suggest me for the followings points:-
(i) For calculating Circumferential Stress at Horn of Saddle, Pvelite does not consider thickness of wear/wrapper plate except when saddle location satisfy A<= R/2 condition.I think it has nothing to do with saddle location as for bending both shell and wrapper plate thickness play their role. I studied from D. Moss, that also not take into account wrapper plate thickness but from Zick Analysis Papers which states wrapper plate thickness shall be taken into account if saddle location is near to head but it does not tell how much near ?In my opinion both thicknesses i.e. shell and wrapper thickness shall be taken into account.
(ii) For calculating required Anochor Bolt area for Shear Stress Pvelite takes Bolt Allowable Stress corresponding to Pressure bolt's allowable stress while Criteria for allowable stress for structural parts are different i.e.
For Tension, Allowable Stress = 0.6 x Sy
For Shear, Allowable Stress = 0.4 x Sy
For Bending, Allowable Stress = 0.66 x Sy
where, Sy = Yield Stress
(iii) Also load due to Friction force (Cofficient of friction X Operating Weight) shall be shared only by fixed saddle support.
Hence, Required anchor bolt area = Frictional Force / (N * Allowable shear stress)
where, N = No. of Anchor bolts for Fixed Saddle.
Am I right ?
Saurabh Gajwani
Engineer- Mechanical (Static Equipments)
Saipem Triune Projects Pvt. Ltd.
New Delhi - 110044
Mobile :- 9873732200
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saurabh