Question about pipe component drawing tolerances

[joedvo]

I am reviewing a German flow meter diagram. Many of the dimensions on this drawing have the typical plus or minus tolerances. Several others have a superscript or subscript tolerance. I am trying to determine the minimum thickness. If the outer diameter of this pipe component is 114mm with a subscript of -0.3mm, does that mean the OD can reduce up to 0.3mm or does it mean that the OD can exceed the nominal 114mm by 0.3mm? I am also in need of a reference standard that explains this, where can I find this in writing? Thank you!

 

[pennpiper]

I think you are in the wrong sector of the Forum You might want to try
"Drafting Standards, GD&T & Tolerance Analysis Forum"