When FEA is required due to abnormal condition or critical condition,
load combination shall be referred Figure 5.1 of ASME VIII Div.2(2013 ed).
2017년 2월 23일 목요일
[Engineering][Knowledge]Requirement for bottom & annular plate welding seam distance
As per para.5.1.5.4.2 of API 650(12th ed),
5.1.5.4 Lap-Welded Bottom Joints
5.1.5.4.2 Three-plate laps in tank bottoms shall be at least 300 mm (12 in.) from each other, from the tank shell, and from joints between annular plates and the bottom. A three-plate lap is created where three plates come together and all plates are joined to one another by lap welds. A location where a pair of bottom plates are lap-welded to each other and are lapped onto an annular plate constitutes a three-plate lap, but lapping a single bottom plate onto a butt-welded annular plate splice does not constitute a three-plate lap weld since the two annular plates are not joined together by a lap weld. These lap joint connections to the butt-weld annular plate are illustrated in Figure 5.3d.
But, in case of weld seam between shell and annular plate, Minimum distance shall be kept as 300 mm.
5.1.5.4 Lap-Welded Bottom Joints
5.1.5.4.2 Three-plate laps in tank bottoms shall be at least 300 mm (12 in.) from each other, from the tank shell, and from joints between annular plates and the bottom. A three-plate lap is created where three plates come together and all plates are joined to one another by lap welds. A location where a pair of bottom plates are lap-welded to each other and are lapped onto an annular plate constitutes a three-plate lap, but lapping a single bottom plate onto a butt-welded annular plate splice does not constitute a three-plate lap weld since the two annular plates are not joined together by a lap weld. These lap joint connections to the butt-weld annular plate are illustrated in Figure 5.3d.
But, in case of weld seam between shell and annular plate, Minimum distance shall be kept as 300 mm.
[Engineering][Knowledge]Leaking test requirement for shop assembled tank
As per Annex J of API 650(12th ed),
J.4.2.2 Testing
Unless otherwise specified by the Purchaser, as an alternative to the requirements of 7.3.2 through 7.3.7, a tank may be shop tested for leaks by the following method:
a) The tank bottom shall be braced by securely attaching an external stiffening member as required to prevent permanent deformation during the test.
b) All openings shall be closed with plugs or covers as needed. Bolts and gaskets of the size and type required for final installation shall be used during the test.
c) An internal air pressure of 14 kPa to 21 kPa (2 lbf/in.2 to 3 lbf/in.2) gauge shall be applied to the tank. For tanks with a diameter of 3.7 m (12 ft) or less, a maximum pressure of 35 kPa (5 lbf/in.2) gauge shall be used.
d) Soap film, linseed oil, or another material suitable for the detection of leaks shall be applied to all shell, bottom, roof, and attachment welds, and the tank shall be carefully examined for leaks.
e) After the air pressure is released, the external stiffening member shall be removed, and any weld scars shall be repaired.
J.4.2.2 Testing
Unless otherwise specified by the Purchaser, as an alternative to the requirements of 7.3.2 through 7.3.7, a tank may be shop tested for leaks by the following method:
a) The tank bottom shall be braced by securely attaching an external stiffening member as required to prevent permanent deformation during the test.
b) All openings shall be closed with plugs or covers as needed. Bolts and gaskets of the size and type required for final installation shall be used during the test.
c) An internal air pressure of 14 kPa to 21 kPa (2 lbf/in.2 to 3 lbf/in.2) gauge shall be applied to the tank. For tanks with a diameter of 3.7 m (12 ft) or less, a maximum pressure of 35 kPa (5 lbf/in.2) gauge shall be used.
d) Soap film, linseed oil, or another material suitable for the detection of leaks shall be applied to all shell, bottom, roof, and attachment welds, and the tank shall be carefully examined for leaks.
e) After the air pressure is released, the external stiffening member shall be removed, and any weld scars shall be repaired.
[Engineering][Knowledge]Ejector design - differencial head
When you design ejectors and it is for discharge fluid in sump,
You should take care fluid head by sump depth.
If it is not available to get exact information, you should consider 7 meters at least.
You should take care fluid head by sump depth.
If it is not available to get exact information, you should consider 7 meters at least.
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