Threaded pipe min wall thickness
Threaded pipe min wall thickness
(OP)
API 570 defines required thickness as the lesser of pressure design thickness or structural design thickness. Pressure design thickness is defined as "minimum thickness without corrosion allowance based on design code calculations for pressure."
Let's say pressure design governs our threaded pipe and the code is B31.3. Pressure design thickness is 't' in 304.1.1. 'c' is the sum of all allowances - corrosion, erosion, and mechanical allowances. Say I calculate t=1.5, CA=.06, and thread allowance =.06 (i.e. c=.12). Am I correct that the required thickness would be 1.44"? In other words we don't take out the mechanical allowance in figuring the required thickness as defined in API 570?
Let's say pressure design governs our threaded pipe and the code is B31.3. Pressure design thickness is 't' in 304.1.1. 'c' is the sum of all allowances - corrosion, erosion, and mechanical allowances. Say I calculate t=1.5, CA=.06, and thread allowance =.06 (i.e. c=.12). Am I correct that the required thickness would be 1.44"? In other words we don't take out the mechanical allowance in figuring the required thickness as defined in API 570?





RE: Threaded pipe min wall thickness
The pressure design thickness would be 1.5
The required design thickness using threaded pipe is 1.56
The required B31.4 design thickness including thread and the required corrosion allowance is 1.62
Not having read it, but not that it makes a difference, I can't imagine anybody caring what API 570 may, or may not, say in regard to the required thickness for a B31.3 design code. B31.3 decides the minimum thickness that it needs to be, given a typical installation. The piping engineer decides if it should be more. Nobody else can say it should be less.
RE: Threaded pipe min wall thickness
RE: Threaded pipe min wall thickness
RE: Threaded pipe min wall thickness
RE: Threaded pipe min wall thickness
RE: Threaded pipe min wall thickness
RE: Threaded pipe min wall thickness
RE: Threaded pipe min wall thickness