ASME Flanged and Dished Head

ASME flanged and dished head made by Dingjin means the dished heads with straight flange.

Impact on stress

After the curved surface of the head is connected to the cylinder, under the action of internal pressure, the cylinder expands radially, and the bottom edge of the head shell contracts radially, generating shear stress and bending moment at the connection. These stresses are superimposed on the membrane stress to form the maximum stress of the head. The setting of the straight edge section avoids the superposition of the bending stress at the head and the stress of the butt weld of the cylinder.

Impact on manufacturing

The design of the straight edge section of the head is conducive to cutting part or all of the straight edge when it is difficult to repair due to severe edge wrinkling after forming, and the assembly of the head and the cylinder, and is also conducive to the operation of RT non-destructive testing.

Selection standard of the straight edge section height of the top gold head

1. Select the straight edge height according to the nominal diameter of the head. When DN≤2000mm, the straight edge height h should be 25mm; when the nominal diameter of the head DN>2000mm, the straight edge height h should be 40mm, and the straight edge height tolerance is (-5%~10%)h (meeting asme specifications).

2. Select the straight edge height according to the thickness of the head. When δ≤10mm, h should be 25mm; when 10＜δ≤30mm, h should be 40mm; when δ＞30mm, h should be 50mm, which also meets the ASME specifications.

After the new dished head is processed, it is best to use manual welding during installation. This welding method has a higher density of capacity than that of the small line. It can also well reduce the heat inputting during welding, reduce the sensitized processing range to the minimum as far as possible, and effectively avoid larger crystal particles in the heat affected zone.the crystal particles become larger and lead to serious embrittlement phenomenon, so the stress caused by welding is well reduced.

If the stainless steel dished head supplied by Dalian Dingjin will be installed in an isolated environment of sulfur dioxide, and a layer of anti-corrosion coating will be added to the outside of the equipment.Meanwhile, it is necessary to use a home improvement coil for cooling treatment, also good to eliminate the spray device because the entire coil is wrapped.