App. 9 – Item Modeling:
1. TOWER:
1.1. By default analyst should use the more conservative modeling of nozzle by
using anchor with cnode (see below). Analyst may use the WRC 297 for
overcome overstress in complex system in occasional cases.
1.2. Modeling of the skirt:
1.2.1.
1.2.2.
1.2.3.
1.2.4.
1.2.5.
Enter the dimensions of the skirt accordingly.
Calculate the skirt average temp.
Enter 0 bar pressure.
Enter the anchor at the base.
Use the correct thk. Of the plates.
1.3. Modeling the tower by sections acc. to the tower drawings (i.e. O.D. and
section thk. Temp. and press. Fluid density up to the HHLL)
1.4. Nozzle modeling:
1.4.1.
At the correct elevation using a rigid element no weight with the same
properties as the tower.
1.4.2.
Modeling the nozzle using the nozzle true dimension (i.e. dia. And wall
thk.) starting with an anchor with cnode.
1.4.3.
Add the flange
1.4.4.
Alternative option is to use the WRC 297 option (optional)
Enter the values needed from vessel drawings.
1.5. Nozzles on heads can only be modeled as in para. 1.4.2. due to the limitation of
WRC 297.
1.5.1.
Model a rigid no weight to the point on head.
1.5.2.
Use an anchor with cnode to connect the nozzle.
2. VESSEL:
2.1.
2.2.
The same principle as towers concerning the nozzles.
Supports will be modeled as shown in CAESAR II application guide
chapter 6.
3. PUMPS:
3.1.
3.2.
Model it as rigid elements with the diameters of suction & discharge
sides adhering to the pump dwg. (or even of larger dia. but no way
lesser).
The fix point or the location for pump anchor. Go through the pump dwg.
thoroughly to confirm the type of pump supporting, meaning whether it's
a centerline supported pump (central pedestal type) or off-centre
supported or may be of some other type.
FLANGE WEIGHT
CALCULATED
MANUALY USING
EXCEL FILE
NO WEIGHT
PUMP FIX POINT
SAME PROPERTIES
AS SUCTION PIPE
SAME PROPERTIES
AS DISCHARGE
PIPE
4. Safety Valves:
4.1.
4.2.
4.3.
4.4.
Safety valves should be model as two rigid elements perpendicular to
each other.
Weight of each segment will be half of the valve weight.
Diameter and w.t. as the pipe inlet and outlet.
Reaction forces will be applied depending on the system (closed or
opened).