QUALITY ASSURANCE

AWWA Standard Flange


Dimensional tolerances

Ring type Slip-on and Blind flanges

HUB type slip-on

O.D.


<=24"

+/- 0.6"(1.6mm)

O.D.


<=24"

+/- 0.6"(1.6mm)

>24"

+/- .12"(3.2mm)

>24"

+/- .12"(3.2mm)

I.D.



Socket-Welding

10" and Samller
+.03"(0.8mm),-0"

I.D.



10" and Samller

+.03"(0.8mm)

Slip-on and 
Lap Joint


12" and Larger
+.06"(1.6mm),-0"


12"-18"

+/-.06"(1.6mm)

20"-42"

+.12"(3.2mm)
+.06"(1.6mm)

O.D. of Hub


<=12"

+.09"(2.4mm),
-.06"(1.6mm)

Diameter of
Contact Face


0.06" Raised Face


+/-.03"(0.8mm)


14"-42"

+/-.12"(3.2mm)

Diameter of Contact face


0.06" Raised Face


+/- .03"(0.8mm)


Diameter of Hub at base


X<=24"

+/-.06"(1.6mm)

X>24"

+/-.12"(3.2mm)

Deameter of Contact face


<=10"

+.03"(0.8mm),
-0"

Diameter of Hub at point of Welding


<=5"

+.09"(2.4mm),
-.03"(0.8mm)

12"-42"

+.06"(1.6mm),
-0"

>=6"

+.16"(4.0mm),
-.03"(0.8mm)

Drilling




Bolt Circle


1/2"-24"
/26"-42"

Drilling




Bolt Circle


1/2"-24"
/26"-42"

+/-.06"(1.6mm)
+/-.06"

+/-.06"(1.6mm)
+/-.06"

Bolt hole
spacing

+/-.03"(0.8mm)

Bolt hole
spacing

+/-.03"(0.8mm)

Eccentricity of Bolt circle with respect to bore

.03" Max.
(0.8mm)

Eccentricity of Bolt circle with respect to bore

.03" Max.
(0.8mm)

Thickness


18"& Small

+.12"(3.2mm),-0"

Thickness


18"& Small

+.12"(3.2mm),-0"

20"-42"

+.19"(1.6mm)

20"-42"

+.19"(1.6mm)

Length Thru Hub


<=10"

+/-.06"(1.6mm)

Length Thru Hub


<=10"

+/-.06"(1.6mm)

12"-42"

+/1.12"(3.2mm)

12"-42"

+/1.12"(3.2mm)


These tolerances are a part of ANSI B16.5 and AWWA C207-01 Sec. 4.2 except where noted otherwise.  The limits given are maximum.  Rigid inspection procedure assures the maintenance of high standards of accuracy in regular day to day production.