Loads and Vertical Vessels

All of the loads that must be considered (and then possibly neglected) are:

• Weight of vessel and normal contents under operating or test conditions
• Superimposed static reactions from weight of attached items (e.g., motors, machinery, other vessels, piping, linings, insulation)
• Loads at attached internal components or vessel supports - particularly trays that support liquid and are attached to the shell
• Wind, including vibration from vortex shedding (fatigue), snow, seismic reactions
• Cyclic and dynamic reactions caused by pressure or thermal variations, equipment mounted on vessel, and mechanical loadings
• Test pressure combined with hydrostatic weight
• Impact reactions (e.g., from fluid shock) effects of fluid flow
• Temperature gradients within vessel component and differential thermal expansion between vessel components
• stresses imposed by damage protection devices attached to shell
• Reactions from piping systems
• The restricted thermal expansion on attachment of piping systems to the vessel, and on its hangers or anchors
• The weight of valves, pumps, blowers, and rotating machinery. (must ensure they are properly balanced and supported)
  
• Other loads due to various postulated accidents must also be considered.

The loads may further categorized into:

• Categories of loads:
  

1. General loads - applied more of less continuously across a vessel section
1. Pressure loads - internal or external (design, operating, hydrotest, and hydrostatic head of liquid.
2. Moment loads - due to wind, seismic, erection, transportation
3. Compressive / tensile loads - due to dead weight, installed equipment, ladders, platforms, piping and vessel contents.
4. Thermal loads - differential temperature across vessel skirt and vessel shell.
1. Local loads - due to reactions from supports, internals, attached piping, attached equipment, platforms, ladders, mixers, etc..
1. Radial load - inward or outward
2. Shear load - longitudinal or circumferential
3. Torsional load
4. Tangential load
5. Moment load - longitudinal or circumferential.
6. Thermal load.

• Types of loadings:

1. Steady load - longterm duration, continuous
1. Internal/external pressure.
2. Dead weights.
3. Vessel contents.
4. Loadings due to attached piping and equipment
5. Loadings to and from vessel supports.
6. Thermal loads.
7. Wind loads.
2. Non-steady loads
1. Shop and field hydotests
2. Earthquake
3. Erection
4. Transportation
5. Upset, emergency
6. Thermal loads
7. Start-up / shut-down
   

What are the loads to be considered for axial force on vertical vessel?

See above list - but the main ones to consider are weight of vessel, contents, platforms, attachments, insulation, refractory/.............

What are the loads to be considered for net sectional bending moment for vertical vessel.

See above list - but the main ones to consider are wind, seismic, erection, transportation, any eccentric loads from weight of platforms/piping/equipment, or eccentric loads due to thermal expansion and restriction from structural supports.

What do consider for torsional shell moment of vertical shell?

See above list - but the main ones would be piping reactions (lateral/hillside), fluid dynamic effects, wind on an unsymmetrical vessel (due to platforms)

Dear Guest.

In addition to your good reply, I like to advise paresh_career001 to look for any Pressure Vessel Design Handbook.