SECTION 8

AMERICANFlanged Pipe

8-1

AMERICAN Flanged Pipe

The principal standards covering Flanged Pipe are ANSI/AWWA C115/A21.15and ANSI/AWWA C110/A21.10. These and other standards are referencedthroughout this Section either by the full ANSI/AWWA designation or by onlythe AWWA numbering, such as AWWA C115.

AMERICAN produces 4- 64 ductileiron flanged pipe with threaded flangesfor water or other liquids in accordancewith AWWA C115. Maximum length offlanged pipe is 176, 190, 196, or200, depending on size; any length lessthan maximum can be furnished down tominimum practical lengths, varying alsowith pipe size. Flanges generally arethreaded on all flanged pipe, except forshort lengths of pipe which may be pro-duced statically with integrally cast flangesas shown in Table Nos. 8-9 and 8-10; staticcastings are manufactured in accordancewith applicable requirements of AWWAC110.

Flanged pipe is generally specified foraboveground service for air, water,sewage, oil and other liquids where rigid,restrained joints are needed. It is widelyused in industrial piping systems, watertreatment plants and sewage treatmentplants, and for other interior piping.

Long runs of flanged pipe should nor-mally include design provisions for thermalexpansion and contraction, such as flexiblejoints or couplings at strategic intervals.

Pipe may be furnished with one endflanged and the other end with Fastite bell,mechanical joint bell, restrained joint bell,plain end, grooved or shouldered end, orwith other type end as may be required.

The underground use of the flangedjoint is generally not recommended due to

the rigidity of the joint as noted in appen-dices of appropriate ANSI/AWWA standards.

Flanged pipe is rated for a maximumworking pressure of at least 250 psi asspecified in the tables in this Section. TheAWWA C110 and C115 flanges (as well asthe flanges faced and drilled per ANSIB16.1 Class 250) are also rated for maxi-mum water working pressure of at least250 psi. The flanges faced and drilled perANSI B16.1 Class 250 are special; they donot match other flanges and are infre-quently furnished. AMERICAN furnishesthese only as a transition from equipmentwith these flanges to regular AWWAC110 or C115 flanges. These flangesfaced and drilled per ANSI B16.1 Class250 are shown in Table Nos. 8-11, 8-12and 8-13 which are shaded to signify theirspecial nature. AMERICAN flanged pipe insizes 24"and smaller is rated for 350 psiworking pressure only when AMERICANToruseal gaskets are used. In some casesother sizes of flanged pipe have been sup-plied for working pressures greater than250 psi, again when joined withAMERICAN Toruseal gaskets. CheckAMERICAN for details.

Coatings and LiningsThe standard outside coating for

flanged pipe is a one-mil-thick asphaltic paint, but other outside coatings perSection 11 can be furnished when specified.

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While other linings are available as describedin Section 11, cement lining, per AWWAC104, is usually furnished in flanged piping.Where AMERICAN is given the option,flanged pipe is normally furnished cementlined depending on availability.

A rust preventive coating is applied tothe machined faces of the flanges; this coat-ing may be removed prior to installation.

Pipe Barrel and FlangesDuctile iron pipe barrels conform to

the requirements of AWWA C151. Allflanges furnished by AMERICAN forthreading on ductile iron pipe are ductileiron in accordance with AWWA C115.(AMERICAN recommends only ductileiron flanges for strength and safety,though AWWA C115 currently allowsboth ductile iron and gray iron flanges.)

Flanges conform to the chemical andphysical properties specified for ductileiron fittings in AWWA C110.

The minus thickness tolerances of thepipe barrels are shown below.

Pipe barrels and flanges have taperedpipe threads (NPT) in accordance withANSI B2.1 adapted to the ductile iron pipeoutside diameters. The flange is threadedonto the pipe and machine tightened untilthe pipe end projects beyond the face ofthe flange; it is then machined to give aflush finish of the pipe end and flange andto ensure that the flange face is perpen-dicular to the axis of the pipe. The flangeis designed so that a shroud substantiallycovers the working threads of the pipe forthread protection. Prior to assembly of theflange on the pipe, a commercial-grade

thread compound is applied to the threadsto ensure leak-free fabrication.

AMERICAN Flanged Pipe is shop fab-ricated in accordance with AWWA C115and threading at the job site is not recom-mended. Flanges furnished on pipe arenot interchangeable in the field and gen-erally cannot be removed after fabricationwithout damaging the pipe and/or flangethreads. If installation conditions requireassembly of the flange on the job, theflange may be factory assembled to ahand-tight condition. This permitsremoval and re-assembly at the job site atwhich time suitable thread compoundmust be used. Hand-tight flangesshould be limited to 16 and smaller sizesbecause of the difficulty in tighteninglarger flanges at the job site.

JOINT MATERIALSJoint materials are normally furnished

for all mechanical joint bell openings onpipe or fittings. With the exception ofAMERICAN Toruseal gaskets specificallyrecommended for superior performance,flanged joint materials are not normallyfurnished by AMERICAN, although theyare generally available from stock. SeeTable Nos. 8-2 in this section and 8-3 inDetails and Accessories.

Since flanged bolts are not generallyfurnished by AMERICAN, the following isgiven for information only.

Note: An additional minus tolerance of 0.02" is permittedalong the barrel of the pipe for a distance not to exceed 12".

Table No. 8-1

4"-8" 0.0510"-12" 0.0614"-42" 0.0748" 0.08

54"-64" 0.09

Pipe Sizein.

Minus ToleranceAWWA C151

in.

1Ductile iron flange; 2Ductile ironpipe barrel; 3AMERICAN StandardPipe Threads, ANSI B2.1, adapted toductile iron outside diameters; 4Pipeend and barrel machined simultaneouslyto a flush finish; and 5Shroud.

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Notes:*Pressure rating designated is maximum water working pressure and is based on the 350 psi allowable rating of 24" and smaller flanges in C111 and the

250 psi maximum rating of other sizes of C110 or C115 flanges. Contact AMERICAN on higher pressure or temperature requirements.**Bolt torque applicable only to flanged joints with Toruseal gaskets.The 64" Toruseal gasket contains an additional torus or bead to accommodate bolting a 64" C115 or C153 flange to a standard 66" steel flange.Clean flange faces and faced pipe ends thoroughly prior to installation. Do not use joint or gasket compounds with Toruseal gas-

kets (assemble joints dry).For use with standard flange bolts. Holes match AWWA C110, C111, and C115 flange drilling. They also match certain flange drilling classes of AWWA

C207 and ANSI B16.1 and B16.42 flanges.Toruseal gaskets may be used with steel pipe flanges in the 14"-54" sizes in some cases. Check AMERICAN for details, or when connecting to any flange

configured differently than flanges per AWWA C110 or C115.

Bolts and NutsSize, length and number of bolts and

nuts are shown in Table Nos. 8-3 (Details andAccessories-AWWA C110 or C115 flange)and 8-11 (Details and Accessories-flangefaced and drilled per ANSI B16.1 Class 250).Bolts are specified in ANSI B18.2.1 and nutsare specified in ANSI B18.2.2. Bolts and nutsof low-carbon steel conforming to ASTMA307 are specified in the Appendix ofAWWA C110 and C115 for flanged pipewhen rubber gaskets are used. Nuts of regu-lar or heavy hex design are used according tocustomer specifications. Also, per theAppendix of AWWA C110 and C115, high-strength bolts should not be used when agray iron flange is involved in the connection.

AMERICANToruseal FlangeGasket

The AMERICAN Toruseal flange gasketis available forimproved joint perfor-mance. It is vastly supe-rior to conventionalfull-face or ring gaskets.

Although recommended for all normal waterand sewer service, it especially must be used indemanding services such as very large diame-ter flanged piping, specially designed long-span installations (i.e. spans involving 2 or 3

lengths of pipe) or with any undergroundflanges* that could be subjected to undesirablebeam loading. Toruseal gaskets are normallyfurnished of high-quality black, molded SBRrubber with required properties perANSI/AWWA C111/A21.11. StandardToruseal SBR rubber gaskets are ANSI/NSFStandard 61 certified for contact with potablewater.Other type rubber is available on specialorder. AMERICAN Toruseal gaskets meet thedescription of specially designed gasketsshown in the appendices of AWWA C110,C111, and C115, and special gaskets shownin the body of AWWA C111.

GasketsAMERICAN Toruseal gaskets are rec-

ommended for AWWA standard flangedjoints in normal water and sewage service.The ANSI B16.21 standard specifies theinside of 3-12 non-metallic full-face andring gaskets to be greater (the same asstandard steel pipe outside diameters) thannominal. Any flat gaskets used for ductileiron flanged pipe must have nominalinside diameters as shown in the appendixof ANSI/AWWA C115/A21.15, not thelarger inside diameters per ANSI B16.21.The larger I.D. gaskets per ANSI B16.21are not recommended by AMERICAN.

Table No. 8-2

4 350 0.3 100 6 350 0.3 150 8 350 0.5 150 10 350 0.6 200 12 350 0.8 200 14 350 0.9 250 16 350 1.1 250 18 350