Question
Why is design pressure considered twice for head calculation in EN 13445-3?
This leads to the higher required thickness calculations, Please clarify.
Answer
The design pressure (P) is doubled due to the opening being closer to the knuckle.
Please refer to the code clause below for your reference:
In this case, since one of the nozzles (4a) is located in the knuckle region of the head, the design pressure is doubled in accordance with clause 7.7.2 mentioned above.
Avoidance: Relocate the nozzle into the central part of the head or increase the thickness to meet the code requirement.