{
  "title": "Pipeline stress and initial-route planning methods",
  "scope": "Unit-bound adopted historical pipeline methods; not current code/project acceptance or final QRA",
  "stress": {
    "equations": {
      "hoop": "Sh=P D/(2t)",
      "restrained": "SL=mu(Sh-P)-E alpha (T2-T1)",
      "unrestrained": "SL=Sh/2+Mb/Z",
      "shear": "Ss=torque/(2Z)+2Fs/A",
      "equivalent": "Seq=sqrt(Sh^2+SL^2-Sh SL+3Ss^2)"
    },
    "units": {
      "P_stresses_E": "MPa=N/mm2",
      "D_t": "mm, required physical dimension not nominal size",
      "moments_torque": "N mm",
      "Z": "mm3",
      "Fs": "N",
      "A": "mm2 pipe wall",
      "alpha": "1/K",
      "delta_temperature": "K or C difference",
      "mu": "dimensionless"
    },
    "wall": "Operation uses nominal minus corrosion allowance under this method",
    "local_equivalent_yield_percent": {
      "installation": 96,
      "hydrotest": 100,
      "operation": 90
    },
    "exception": "Installation fraction not applicable where yielding integral, including reeling/J-tube pull-in; collapse/fatigue/strain and actualmodel independent",
    "hypothetical": {
      "P_MPa": 5,
      "D_mm": 400,
      "t_evaluated_mm": 10,
      "mu": 0.3,
      "E_MPa": 200000,
      "alpha_per_K": 1.2e-05,
      "deltaT_K": 50,
      "bending_over_Z_MPa": 20,
      "shear_MPa": 0,
      "Sh_MPa": 100.0,
      "SL_restrained_MPa": -91.5,
      "SL_unrestrained_MPa": 70.0,
      "Seq_restrained_MPa": 165.8983122277017,
      "Seq_unrestrained_MPa": 88.88194417315589,
      "acceptance": "No SMYS or project comparison; different assumed limiting states"
    }
  },
  "route": {
    "expressions": {
      "factor_not_exceeding_0_72": "d=Qf(D^2/32000+D/160+11)(P/32+1.4)",
      "factor_not_exceeding_0_4": "d=Qf(0.7-t/21)(P+82)"
    },
    "units": {
      "d": "m",
      "D_t": "mm",
      "P_MAOP": "bar gauge",
      "Qf": "dimensionless fluid factor"
    },
    "input_rules": {
      "diameter_below_150_mm": "Use150",
      "pressure_below_20_bar_gauge": "Use20",
      "wall_below_9_5_mm": "May use9.5",
      "wall_above_13_5_mm": "Shall use13.5"
    },
    "fluid_factors": {
      "A_B": 0,
      "C": 0.3,
      "D_methane": 0.5,
      "D_ethylene": 0.8,
      "D_LPG": 1,
      "D_NGL": 1.25,
      "D_hydrogen": 0.45,
      "D_ammonia": 2.5
    },
    "limits": "Access retained even atzero factor; unknown-fluid analogy needs hazard assessment; overlappingwritteninequalities not permission tochoose smaller output; finalQRA and actual governing requirements independent",
    "hypothetical": {
      "D_mm": 300,
      "P_bar_gauge": 60,
      "Qf": 0.5,
      "t_mm": 9.5,
      "first_distance_m": 25.68828125,
      "second_distance_m": 17.58095238095238
    }
  }
}