AWWA Class F-Ring and Blind Flanges

As per AWWA C207-01 Sec. 1.3, the pressure ratings listed for AWWA Class B, D, E and F flanges are for conditions and temperatures customary in water utility services. The pressure ratings for the flange should be based on the design of the maximum operating pressure plus the anticipated sure pressure. Test pressures should not exceed 125 percent of the ratings. Flange design is based on pressure considerations, not for stresses induced by external moments when pipe acts as a beam. The tables of the AWWA C207-01 standard have been developed using a design stress of 16,000 psi for the working pressure design.

1. Ring flanges available overbored or counterbored per customer specification. 2. Bolt holes shall be drilled 1/8th inch larger in diameter than the nominal diameter of the bolt, except for flanges larger than 84 inch in diameter which shall be drilled 3/16th inch larger than the nominal diameter of the bolt. 3. Drilling same as ANSI/ASME B16.1 125 lb and B16.5 150 lb pattern. 4. Flanges available overdrilled to accommodate insulators. 5. AWWA recommends the use of dished head assemblies as alternate to blind flanges, sizes over 72" nominal. 6. AWWA C207-01 Class B and D Hub Flanges are identical to Industry Standard Class 125 Light Weight Flanges.

AWWA Class E-Hub and Blind Flanges

As per AWWA C207-01 Sec. 1.3, the pressure ratings listed for AWWA Class B, D, E and F flanges are for conditions and temperatures customary in water utility services. The pressure ratings for the flange should be based on the design of the maximum operating pressure plus the anticipated sure pressure. Test pressures should not exceed 125 percent of the ratings. Flange design is based on pressure considerations, not for stresses induced by external moments when pipe acts as a beam. The tables of the AWWA C207-01 standard have been developed using a design stress of 16,000 psi for the working pressure design.

1. Ring flanges available overbored or counterbored per customer specification. 2. Bolt holes shall be drilled 1/8th inch larger in diameter than the nominal diameter of the bolt, except for flanges larger than 84 inch in diameter which shall be drilled 3/16th inch larger than the nominal diameter of the bolt. 3. Drilling same as ANSI/ASME B16.1 125 lb and B16.5 150 lb pattern. 4. Flanges available overdrilled to accommodate insulators. 5. AWWA recommends the use of dished head assemblies as alternate to blind flanges, sizes over 72" nominal. 6. AWWA C207-01 Class B and D Hub Flanges are identical to Industry Standard Class 125 Light Weight Flanges.

AWWA Class E-Ring and Blind Flanges

As per AWWA C207-01 Sec. 1.3, the pressure ratings listed for AWWA Class B, D, E and F flanges are for conditions and temperatures customary in water utility services. The pressure ratings for the flange should be based on the design of the maximum operating pressure plus the anticipated sure pressure. Test pressures should not exceed 125 percent of the ratings. Flange design is based on pressure considerations, not for stresses induced by external moments when pipe acts as a beam. The tables of the AWWA C207-01 standard have been developed using a design stress of 16,000 psi for the working pressure design.

1. Ring flanges available overbored or counterbored per customer specification. 2. Bolt holes shall be drilled 1/8th inch larger in diameter than the nominal diameter of the bolt, except for flanges larger than 84 inch in diameter which shall be drilled 3/16th inch larger than the nominal diameter of the bolt. 3. Drilling same as ANSI/ASME B16.1 125 lb and B16.5 150 lb pattern. 4. Flanges available overdrilled to accommodate insulators. 5. AWWA recommends the use of dished head assemblies as alternate to blind flanges, sizes over 72" nominal. 6. AWWA C207-01 Class B and D Hub Flanges are identical to Industry Standard Class 125 Light Weight Flanges.

AWWA Class B-Hub and Blind Flanges

The blind flange is used to close ends of piping systems. It is a kind of round plate with no center hold but with all the proper bolt holes. This blind flange is available in various sizes and materials and is used to provide positive closer on the ends of pipes, valves or equipment nozzles.

1. Ring flanges available overbored or counterbored per customer specification. 2. Bolt holes shall be drilled 1/8th inch larger in diameter than the nominal diameter of the bolt, except for flanges larger than 84 inch in diameter which shall be drilled 3/16th inch larger than the nominal diameter of the bolt. 3. Drilling same as ANSI/ASME B16.1 125 lb and B16.5 150 lb pattern. 4. Flanges available overdrilled to accommodate insulators. 5. AWWA recommends the use of dished head assemblies as alternate to blind flanges, sizes over 72" nominal. 6. AWWA C207-01 Class B and D Hub Flanges are identical to Industry Standard Class 125 Light Weight Flanges.

Dimensional tolerances for AWWA pipe flanges

Listed below are the Dimensional Tolerances to which flanges are manufactured.  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.

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)