PLSS Temperature Derating Factor

The Temperature derating factor is used in MAOP (Maximum Allowable Operating Pressure) and FFS (Fitness For Service) calculations. The factor is applicable for the Pipeline, Flowline and Pipeline Jumper Equipment Groups. Its value should be between 0.1 and 1.0.

Finding (and Editing) the Temp derating factor

You can find the temperature derating factor in all places where we show the design factor.

PL Design Data section

The Temp. derating factor is shown for all Pipeline Design Codes in the Equipment's PL Design Data section. Although the default value will be determined by the applicable Pipeline Design Code, when needed, the factor can be edited to have any value between 0.1 and 1.0.

Example for ASME B31.4:

Sectioning section

You can also find it in the Equipment's Pipeline data Sectioning section:

FSS Assessment Table

It is shown in the FFS Assessment grid, as it influences the Corrosion Tolerance.

RBA Module 

You will also find it in the RBA module, on the Intermediate Results tab.

Calculations - MAOP and FFS

The Temperature derating factor is used in the Maximum Allowable Operating Pressure (MAOP) calculation:

MAOP (calculated) = Design Factor * (2 * (Nominal WT – Design Corrosion Allowance) * SMYS * Temp. Derating Factor) / Diameter. 

The factor is also used to determine the Corrosion Tolerance as shown in the FFS Assessment Table.

Temperature Derating SPEC field

There is also a TEMPERATURE DERATING INFO Specs. This is a text field that you can use to add more information on the factor that you selected in the Design Code.