AWWA ring flange

American Water Works Association () is an international non-profit, scientific and educational association founded to improve water quality and supply. Established in 1881, it has a membership (as of 2012) of around 50,000 members worldwide.

These tolerances are a part of and AWWA -01 Sec. 4.2 except where noted otherwise.

AWWA flange

Dimensional tolerances for AWWA Standard

These tolerances are a part of ANSI B16.5 and AWWA C207-01 Sec. 4.2 except where noted otherwise.

Listed below are the Dimensional Tolerances to which flanges are manufactured.    The limits given are maximum.

Rigid inspection procedure assures the maintenance of high standards of accuracy in regular day to day production.

Ring type Slip-on and 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)

AWWA Vs. ANSI Flange Standards

Both the AWWA and ANSI have thorough standards for flanges, and the two standards are different in several ways.

Both the AWWA and ANSI have thorough standards for flanges, and the two standards are different in several ways. AWWA standards provide flange properties intended for potable water use only. In contrast, ANSI standards are aimed at industrial flange applications.

For example, ratings are applicable only at atmospheric temperature, while ANSI ratings cover flange installations from -20°F to 1500°F. AWWA standards provide flange properties intended for potable water use only. In contrast, ANSI standards are aimed at industrial flange applications. For example, ratings are applicable only at atmospheric temperature, while ANSI ratings cover flange installations from -20°F to 1500°F.

ANSI covers numbered class flanges from 150 to 2500, and AWWA standards encompass lettered flange classes B, E, F, and the commonly used class D connection. AWWA provides ratings for a much broader range of nominal pipe sizes (3″-144″) than ANSI provides (1/2″-24″).

Finally, ANSI and AWWA flange standards differ in the breadth of applications discussed. ANSI includes information for welded auxiliary connections and tapping, while AWWA does not address those installations. Also, the AWWA standard only encompasses ring, hub type, blind flanges, and threaded iron flanges while the ANSI standard inlcudes all flange types.

This discussion on AWWA flange standards and ANSI flange standards is based on information from ANSI/AWWA C115/A21.15-99: “American National Standard for Flanged Ductile-Iron Pipe with Ductile-Iron or Gray-Iron Threaded Flanges”, ANSI/AWWA C207-94: “AWWA Standard for Steel Pipe Flanges for Waterworks Service-Sizes 4 In. Through 144 In.”, and ANSI B16.5-1981: “Pipe Flanges and Flanged Fittings”.

Related products maybe you like
AWWA Vs. ANSI Flange Standards
Flange materials acc. to ASTM
AWWA and Plate Steel Flanges General Information
size data
Stainless steel caps
Carbon steel caps

Leave a Reply

Your email address will not be published. Required fields are marked *