NOZZLE DESIGN

[Danfort]

HI,

FOR WHICH DESIGN/OPERATING CONDITION IN A NOZZLE WITH WELDS DIRECTLY INTO HEADER OR VESSEL FOR TOTAL INTEGRAL TYPE CONSTRUCTION AND WITH BUTT-WELDED FOR EASE OF NDT OR IN-SERVICE INSPECTION?

THANKS IN ADVANCE.

DAN

 

[austsa]

Dan,
There are various ways for nozzle compensation:
(1) reinforcement pad (non-integral)
(2) self-reinforced nozzle (eg LWNRF)
(3) saddle-type nozzle
Option (1) is non-integral reinf. Option (2) will generally use UT/MPI as NDT methods.
Option (3) utilises butt-weld (in true sense of the word) and can use UT/MPI or RT as NDT methods. Use of option 3 is generally dictated by client and material of construction. Many/some would argue that UT of SS or very high alloy materials is not very reliable, and thus if client requires volumetric NDT, then option 3 is the way to go.
In cases where nozzle diameter relative to vessel diameter is large, option 3 is (generally) unavoidable.
austsa