Raised face spiral finish

[Thirlmere]

Hi guys, ASME B16.5 mentions that a flange face should have a certain roughness and be spiral or concentrically machined.

We have received some valves that AREN'T spiral or concentrically machined but probably do have the required roughness.

They we machined using a milling machine and to me they look unacceptable.

Is the spiral or concentric finish an absolute must or is the surface finish enough to sneak them thru the required standard?

Thanks
Thirlmere

 

[racookpe1978]

Measure them.
Show us what the measurements are, and what the photographs look like.

Your question is like: I am taller than my sister.
Am I tall enough?

 

[Thirlmere]

My question is in relation to the pattern, not the height of groove.
What i'm asking is if the pattern is important or just the surface roughness.

And i don't have a sister

 

[BJI]

Yes the pattern is important, a milling machine will likely create radial grooves across the face and is not acceptable. Depending on the application and gasket type it might still but if you have a look at ASME PCC-1 Appendix D, a radial defect (which this is) is not permitted across the full sealing face for either hard or soft faced gaskets.

Please still post a picture of the raised face machining though!

 

[Thirlmere]

Thanks guys, please see attached photo......

To me that just seems to be non compliant.....Your thoughts?

 

[DSB123]

Looks like they are trying to promote leakage with those grooves. Cannot understand why a reputable valve Company would do that to the sealing face. Not Chinese origin are they??

 

[XL83NL]

I agree with DSB123. This is unaccetpable, they indeed like to promote as much leakage as possible.

 

[Gator]

Curious about thing in center of zoom:

 

[Thirlmere]

I agree that the machining of the gasket face is poor at best, but my question is would it meet the required standard.

Regards
Thirlmere

 

[BJI]

Not compliant.

 

[TGS4]

6.4.5.3 Other Flange Facings. Either a serrated
concentric or serrated spiral finish having a resultant
surface finish from 3.2 m to 6.3 m (125 in. to 250 in.)
average roughness shall be furnished.

(emphasis mine)

The requirement for concentric or spiral is a shall, meaning mandatory requirement. Therefore this flange facing is not compliant. There should be no doubt about this.

 

[SwinnyGG]

That's pretty weird. Looks like to me like it was machined with a face mill, with the part on a rotary table or dividing head.. not sure why you would ever machine a gasket surface that way.

 

[racookpe1978]

Those patterns of radial grooves, all of them criss-crossing each other in addition, means the surface is more likely to leak through. Reject the part. Inspect others received at the same time from the same vender.