Mill test pressure

[jaimeleiva]

I would like to know what exactly means mill test pressure, is the pressure at the factory before a piece of pipe leaves the manufacturing plant or is it a design pressure...?
Thank you

 

[metengr]

Mill test pressure is a pressure test conducted by the mill which supplied the pipe.

 

[JStephen]

I would assume that it is the pressure actually used for testing the pipe in the manufacturing process, and bears no relation to your design pressure. Presumably the design pressure would be lower, particularly if used at higher temperatures. The test pressure should be set by the ASTM standard under which the pipe is made, while the design pressure would be controlled by the pipe or vessel spec the piping is used for.

 

[panduru]

Pardon my ignorance but if I should require pipe for a certain design pressure, should I go for a pipe of about the same mill test pressure? A pipe with mill test pressure of about 3.5 times my design pressure?

How does mill test pressure guide me in evaluating the suitability of the material [pipe, say] for my requirement?

 

[metengr]

You need to review the MTR carefully and determine if the mill test pressure = hydrostatic test pressure per either ASTM or ASME Standard Specifications. I have seen on incoming MTR's mill test pressure as the hydrostatic test pressure.

 

[pvesseleng]

General specification for pipe mill hydrotest is SA 530,
this specification clearly defines the hydrotest pressure.
This pressure test must be conducted by the pipe manufacturer, or another code permitted material certifying
bodies.( PG-11 in section I permits boiler manufacturer making certification, also section VIII Div1. etc..)

 

[amirparviz]

As per ASME Code you should test your piping or equipment system after fabrication with test pressure which is stipulated in Code.
This is regardless of mill pressure test in mill shop.
So we can not consider the mill pressure test instead of field pressure test which is requirement of Code.