Pipeline Buoyancy Analysis R1 6 In

Buoyancy Control

buoyancy

LTRO PROJECT

PIPELINE BUOYANCY ANALYSIS FOR 6" TRUNKLINE

Design Parameter

Pipe Properties-Pipe outside diameter, OD (in.)=6.625Density of pipe, rp (lb/ft)=490.063=0.2836012731lb/in-Pipe wall thickness, tp (in.)=0.562Density of Concrete Saddle, rc (lb/ft)=149.828=0.0867lb/in-Pipe inside diameter, ID (in.)=5.501Density mud soil, m (lb/ft)=94.87=0.0549lb/in-Material=API 5L Gr.X42 SMLSDensity of anti-corrosion coating, a (lb/ft)=56.229=0.0325399306lb/in-SMYS (psi)=42,100Density water, w (lb/ft)=62.429=0.0361lb/in-Each Standard Average Pipe Length (in)=472.44Design Safety Factor SF=1.2-Anti-corrosion coating thickness, ta (in)=0.090Pipe depth of cover (m)=2=78.74015748in

Buoyancy Calculation

a.Weight of Bared PipeCross Sectional Area (CSA) of Pipe wall, Ap=

=10.70 in2

Weight of pipe per unit length, Wp=

=3.04 lb/in

b.Weight of Anti Corrosion CoatingCross Sectional Area (CSA) of coating, Aa=

=1.90 in2 Weight of coating per unit length, Wa=

=0.06 lb/in

c.Pipeline Buoyancy in Open TrenchCross Sectional Area (CSA) of line pipe+coating, At=

=36.37 in2

Weight of displaced water, Ws=(Archimedes' Principle of Buoyancy)

=1.31 lb/in

Cross Sectional area of backfilled soil on top of pipe, Ad=OD x Depth of Cover

=521.65 in2

Pipeline buoyancy per unit length, B=

=-1.78 lb/in

Pipeline buoyancy per joint pipe, Bp=-842.67 lb

Since the pipeline has ngative buoyancy force in the swampy area, concrete set-on weight will not be used as the anti-buoyancy force to prevent the pipeline from floating.

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