Applies To
Product(s):	AutoPIPE Vessel
Version(s):	ALL
Area:	Calculations
Date Logged & Current Version	November 2024 45.00.03.001

Problem:

The following message appears when using AutoPIPE Vessel,

319 HEAD: knuckle radius (1.2 in) not covered by code §UG-32 (j) (diameter=20 in , thickness=0.5 in).

why and how to avoid?

Solution:

We face this error message when the dimensional criteria of Torispherical head are out of the scope of code requirements.
See below code reference, ASME Section VIII Div. 1, UG-32 (i),

As per the code, There are following three criteria for Torispherical Head,

1. The inside crown radius to which an unstayed head is dished shall be not greater than the outside diameter of the skirt of the head.
2. The inside knuckle radius of a torispherical head shall be not less than 6% of the outside diameter of the skirt of the head.
3. But in no case inside knuckle radius is less than 3 times the head thickness.

Refer Below Example,

In this case,

knuckle radius = 1.2 in
Diameter = 20 in
Crown Radius = 20 in
Knuckle Thickness = 0.5 in

In above case, Criteria number 3 is not met., inside knuckle radius is not less than 3 times the head thickness.
To avoid the error you can change the knuckle radius or head thickness.

319 - HEAD: knuckle radius (XX in) not covered by code §UG-32 (j) (diameter=XX in , thickness=XX in

Problem:

Solution: