Stainless Steel Pipe Ovality

In the cross section of the stainless steel pipe, there is a phenomenon that the outer diameters are not equal, that is, there are maximum and minimum outer diameters that are not necessarily perpendicular to each other. The difference between the Maximum outer diameter and the minimum outer diameter is the Ovality (or out-of-roundness). In order to control the ovality, some stainless steel pipe standards stipulate the allowable tolerance of ovality, which is generally specified as not exceeding 80% of the outer diameter tolerance (implemented after negotiation between the supplier and the buyer).

The general requirement standard for stainless steel pipe is ASTM A999. The OD under tolerance on all sizes is -0.031”. The over tolerance increases with OD size but for the range of 1-1/2 to 4 NPS the plus tolerance is also 0.031”. An additional ovality tolerance allowance is permitted for thin wall thickness pipe which is defined as a pipe where the nominal wall thickness is 3% or less of the OD size. In such a case, the OD tolerance range applies to the mean OD and the ovality is permitted to be 1.5% of the OD.

Stainless Steel Tube Dimension
Stainless Steel Tube Guage
ANSI Standard Pipe Chart
Millimeters Inches Conversion Chart
Stainless Steel Tube Weight Calculation Tool
Conversion Table of Temperatue, Length,Mass,Pressure
NPS-Nominal-Pipe-Size
NPS-Nominal-Pipe-Size and DN – Diametre Nominal
Pipe Schedule

Stainless Steel Pipe Ovality

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