American Water Works Association (AWWA) 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 ANSI B16.5 and AWWA C207-01 Sec. 4.2 except where noted otherwise.
Regardless of custom sizing or specifications, the fundamental design of most flanges falls under six common styles created to close, connect, cover, or support pipes and pipe systems.
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 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) |
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| 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) |
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| Drilling | Bolt Circle | 1/2"-24" /26"-42" |
Drilling | Bolt Circle | 1/2"-24" /26"-42" |
| +/-.06"(1.6mm) +/-.06" |
+/-.06"(1.6mm) +/-.06" |
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| 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) |
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| 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) | ||
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, AWWA flange 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, AWWA flange 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”.
Below you will find a short description and definition of each type, completed with an detailed image.
Custom pipe flanges can be manufactured from a wide variety of materials and material grades.
Carbon steel is a popular solution, as are stainless steel and specialty alloys, depending upon the industry. Plate and forged are also common, as are titanium and aluminum for lightweight jobs.
Pipe Flange helps to connect piping components in a piping system with the use of bolted connections and gaskets.
Our manufacturing process is highly sophisticated and is divided into various departments supervised by experienced industry experts.
2. Material Inspection
3. Material Cutting
5. Heat Treatment
6. Forging Rolling
8. Rust Prevention
Requirements are valid for normal situation, in special you have to contact us to introduce.
Beginning with this process,the system controls the quality of all incoming materials as per the raw material test certificate of the material. Mild Steel Flanges ( MS ) are of premium quality that ensures high durability, strength and resistivity to varied non-supporting conditions. Also, checking in each size for chemical and physical properties of these materials at Government approved laboratory.
Dimensions from carbon steel and stainless steel flanges are defined in the ASME B16.5 standard. The material qualities for these flanges are defined in the ASTM standards.
Steel flanges must be packed with seaworthy packing method then delivery to customers, usually the packing way include wooden box, wooden pallet, iron & steel cage, iron & steel pallet etc. Because of the normal wooden boxes or wooden pallets have to do fumigation treatment, we usually use plywood pallet or plywood case or box to pack steel flanges without fumigation treatment. Whatever plywood or iron & steel packing way, they must be seaworthy, strong, waterproof and easy for loading and unloading.
Our team are highly trained and experienced in servicing and producing all types of steel supplies. Whether you've got a large construction project, or need parts for industrial machinery, our team of steel fabrication consultants will ensure that your project is provided with the parts you need, when you need them.
