API 594 Minimum Wall thickness 1

[CarlosEstinos]

Hell All,

I am in the process of approving a 10" Dual plate check valve ANSI 1500LB with hubbed end connections. The specified design standard is API 594. I have a query related to the minimum wall thickness of the valve.

I'm reading that the standard species this type of valve as having a minimum wall thickness of 57mm , is this number an absolute requirement that can have no deviation , or can there be agreed deviations in this value?

The manufacturer im speaking to have shown the minimum wall thickness as being the attached drawing snip. Does anyone have any comments on this?

Any feedback would be greatly appreciated.

Carlos

 

[Danlap]

Wall thickness is related to the wetted parts. Assume there is no internal parts, and the body act as a spool, does the body itself could comprehend Maximum Allowable Design Pressure of Class 1500? Rhetoric question

If your pipeline system (along with this valve) are built in respect with ASME 16.34 (which incorporate API 594), then the answer is Yes. the figure is your minimum threshold.
Choose the least minimum wall thickness from both standard (probably you may interpolate the figure from ASME 16.34) and compare it with API 594, and that is your minimum wall thickness.

However normally, two occasion may waive this conditions:
a. Special material being used. however the body itself should be CE marked as evidence that the design has been approved by higher institution.
b. The operation never reach maximum design pressure. Valve is built in accordance with Class 1500 just to comply with standard dimension. However, both parties (manufacturer and end user) Must acknowledge this condition.

Regards,
MR



Greenfield and Brownfield have one thing in common; Valve(s) is deemed to "run to fail" earlier shall compared to other equipments

 

[reverman]

API 594 refers to B16.34 for wall thickness and B16.34 para 6.1.6 has guidelines for small local areas that have less than the minimum wall thickness.