Since the primary edition of the AWWA Standard C207 was printed in 1952, AWWA flanges have commonly been utilized in waterworks, wastewater, slurry, plant piping, and different mild obligation applications. Pressure rankings for AWWA flanges range from the category B flange rated at 86 psi to the category F flange rated at 300 psi. The AWWA C207-01 normal describes two sorts of slip-on flanges, ring type and hub type which may be used interchangeably if the dimensions given in the usual are used. The standard additionally describes blind flanges. Flanges described in the AWWA C207-01 tables are meant to be used with steel pipe, fittings or appurtenances assembly the necessities of ANSI/AWWA C200, ANSI/AWWA C208, ASTM A134, ASTM 139, or different equal standards. It is additional intended that these flanges be attached by welding in accordance with AWWA C207-01 Sec.4.3.Pressure Ratings
As per AWWA C207-01 Sec. 1.3, the pressure scores listed for AWWA Class B, D, E and F flanges are for circumstances and temperatures customary in water utility companies. The stress rankings for the flange needs to be primarily based on the design of the utmost working pressure plus the anticipated positive strain. Test pressures should not exceed 125 % of the scores. Flange design relies on strain issues, not for stresses induced by exterior moments when pipe acts as a beam. The tables of the AWWA C207-01 commonplace have been developed utilizing a design stress of 16,000 psi for the working stress design.Flange Material
As per AWWA C207-01, Sec 4.1, steel tubing flanges shall be made from seamless forgings, lower from plate as a single piece, steel tubing welded bar rings or segmented and welded plates as per C207-01 Sec 4.2.4.
Forgings shall meet the minimal necessities or ASTM A105 or A181.
Steel plate or bar used within the manufacture of flanges shall meet the following requirements:
1. Tensile energy = 50,000 psi (345 mpa) (min.)
2. Yield power = 32,000 psi (221 mpa) (min.)
3. Carbon = 0.29 p.c (max.)
4. Phosphorous = 0.04 % (max.)
5. Sulfur = 0.05 % (max.)
Plate steel designations that can meet the beforehand listed necessities embody but usually are not limited to the next designation: 1. A362. A516, grade 60, 65, and 70
Pacific Coast Flange Inc will provide mill take a look at experiences displaying conformance to the bodily and chemical requirements for all flanges ordered.Flange Facing
As per AWWA C207-01 Sec 4.2. Here is more in regards to steel tubing (http://sc.sie.gov.hk) stop by the web site. 2, all AWWA flanges shall be flat-confronted without projection or raised area of face. Either a serrated concentric or serrated spiral end having from 24 grooves per inch to 470 grooves per inch shall be used. The reducing instrument employed shall have an approximate 0.06 inch or larger radius. The resultant surface finish shall have a 250 to 500-uin. roughness.Drilling Templates
As per AWWA C207-01 Sec. 4.2.Three drilling templates are in multiples of 4 so that fittings will be make to face any quarter. Bolt holes shall straddle the middle line, except the place special mating situations exist and shall be drilled 1/eight in. (3.2mm) larger in diameter than the nominal diameter of the bolt, besides on flanges bigger that eighty four inches (2,100mm) diameter, bolt holes shall be drilled 3/sixteen inches (4.8mm) bigger than the nominal bolt diameter. Bolt holes may be over drilled by a further 1/8 in (3.2mm) to accommodate insulators or to facilitate alignment with the mating flange.