SUPPORT DESIGNAdditionally, supports, piles, and/or foundations should be adequately designed from a structural and soil-engineering standpoint to safely handle any loads transferred from the pipe.

FIGURE 1 -- SADDLE ANGLE AND WIDTH

BEAM SPAN FOR DUCTILE IRON PIPE ON SUPPORTSDuctile iron pipe is normally manufactured in 6m nominal lengths, depending on the pipe manufacturer. The most common joint used with ductile iron pipe is the push-on-type joint. This rubber-gasketed joint allows a certain amount of deflection and longitudinal displacement while maintaining its hydrostatic seal. This makes these pipe joints ideally suited for normal underground and aboveground installation. The flexibility of the joints reduces the chance of excessive beam stresses occurring. For pipe supported at intervals, however, flexible joints usually require that at least one support be placed under each length of pipe for stability.

Various schemes have been successfully used to obtain longer spans where particular installation conditions presented the need, but these are special design situations and are not specifically addressed in this section. The design presented herein is based upon one support per length of pipe.

 

BEAM DEFLECTION AT CENTER OF SPAN Computations for beam deflection are also based on the simply supported beam concept. This is likewise conservative due to the reality of offset joints. The maximum allowable deflection at mid-span to prevent damage to the cement-mortar lining is limited to:

Where:

Less deflection may be desired. The deflection of the beam may be significant for aesthetic reasons in aboveground installations or possibly for hydraulic reasons in gravity-flow pipelines. Limitations on the deflection, if any, should be determined by the designer as appropriate to a specific installation.

The beam deflection at center span for a uniformly loaded, simply supported beam can be calculated using the following formula:

Where:

INT Design Table For Pipe On Supports For Aboveground Piping

Design Table for Pipe on Supportsfor Aboveground Piping

NominalPipe

Diameter (mm)

KClass

SaddleAngle "ß"

(°)

ClearSpan "L"

(m)

Beam Defl.at Center

of Span "y" (mm)

MinimumSupport

Width (mm)

100 9 90 6 9.680 38

150 9 90 6 5.320 46

200 9 90 6 3.514 53

250 9 90 6 2.494 61

300 9 90 6 1.850 69

350 9 90 6 1.463 76

400 9 90 6 1.175 83

450 8 90 6 1.080 85

500 8 90 6 0.902 92

600 7 90 6 0.756 99

700 7 90 6 0.582 111

800 7 90 6 0.459 124

900 7 90 6 0.371 136

1000 7 90 6 0.307 148

1200 7 90 6 0.221 173

1400 7 90 6 0.168 197

1500 7 90 6 0.148 209

1600 7 90 6 0.131 221

Notes:Calculations for maximum support reaction stress, midspan deflection, and flexural stress are based on design principles from DIPRA's "Design of Ductile Iron Pipe On Supports." This analysis assumes a simply supported beam.

Weight calculations are based on ACIPCO Fastite® pipe full of water with standard ISO 4179 cement linings.

Determining Hoop Stress as % of SMYS

•Barlow’s Formula is the common method for determining hoop stress in the wall of a pipe.Hoop Stress = PD / 2t•Solving for Pressure and using the yield strength for the pipe results in a formula that looks a lot like the §192 design formula.

P = 2t * S / D•This will give you the pressure that results in 100% Hoop Stressor the pressure at 100% SMYS. Dividing your MAOP by this pressure will give you the maximum % SMYS that the pipeline is operated at.

Example Calculation

•4 inch pipeline (OD = 4.5), wall thickness 0.188 (t = 0.188), MAOP = 720 psi, SMYS = 52,000 psi(X-52)•100% SMYS Pressure = 52,000 * 2(0.188 in) / 4.5 = 4345 psi•Hoop Stress as a % of SMYS = 720 psi/ 4345 psi= 17%•Since 17% is less than 20% criteria, this line is Type B

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Maximum deflection shall be < L/600, L= span in meter

Specifications

ITEM:weldolet PRESSURE: 2000LB, 3000LB, 6000LB, 9000LB MATERIAL: CARBON STEEL, STAINLESS STEEL

olet Features:1)Size: 1/8" -4"2)Joint: SW / NPT / BSP3)Standard: 1. ASME, B16.11;B16.9 2. GB12459-90 3. GB/T13401-92 4. GB/T21635 5. GB/T216344)Pressure: 2000LB, 3000LB, 6000LB, 9000LB5)Material: Carbon steel, Stainless steel: (1Cr18Ni9Ti, Cr18Ni9, 0Cr19Ni10, 0Cr17Ni12Mo2Ti, 304, 304L, 316, 316L etc)Carbon steel (20#, ASTM A105, 16Mn, ASTM A403, ASTM A234), Alloy steel (Cr5Mo, 16MnR, 15CrMo, 12Cr1MoV, 10CrMo910)6)Thickness: Sch40, Sch80, Sch160, XXS7)Delivery: 10,000/month, 8)Packing: Carton/timber box.