Input variables

Generic variables

These variables can be found in virtually all reports as input variables

Gas infrastructure

Location of the facility near which the gas infrastructure is situated.

Underground, except a station
In a tunnel
Station

Maximum Design Factor – f_o

Factor for restricting the allowable stress. The value can be chosen smaller, but not larger.

Design Pressure – P_d

Pressure assumed to be present in the component according to the design terms

Design Temperature – T_d

Temperature assumed to be present in the component according to the design terms

Material (header/branch)

Name of selected material used for the construction of the component

Specific variables

These variables are component specific

Outside Diameter header and branch – D_e, D_e2: Outside diameter of the attached part. The diameter runs from the outside of the wall to the opposite outside of the wall, through the center of the circle. Generally the branch is smaller in diameter than the header.
Nominal Thickness header, branch and reinforcement – d_n, d_2n, d_3n: Thickness ‘as is’, meaning it is the design thickness taking into account corrosion and tolerance.
Corrosion header and branch – Ca, Ca₂: Amount of thickness that accounts for the possible effects of corrosions.
Tolerance header, branch and reinforcement – tol, tol₂, tol₃: Tolerance in thickness for production
Strength reduction coefficient header and branch – z_h, z_b: Effectiveness of the strength, depending on whether joints are seamless, welded, or expected to perform worse than the base material properties
Angle centerline branch – y: Angle between the centerline of the branch and the line perpendicular to the header centerline.
Reinforcement width – w_r: Width of the reinforcement. The width equals the outer radius minus the inner radius.

Stubon dimensions

Stubon areas

Calculated Values

Allowable Operating Stress header, branch and reinforcement – f, f₁, f₂: Stress in the component at which it is still allowed (without failure) to use the component
Allowable stress at 20 °C header, branch and reinforcement – f_t, f_1t, f_2t: Stress in the component at which it is still allowed (without failure) to use the component at 20 °C ambient temperature
Stress ratio branch/header – f₁/f, f_1t/f_t: Ratio of operating stresses of the branch and the header. This ratio must be ≤ 1.
Stress ratio reinforcement/header – f₂/f, f_2t/f_t: Ratio of operating stresses of the reinforcement and the header. This ratio must be ≤ 1.
Required thickness header pipe and branch pipe – d_r, d_2r: Based on the input, this is the calculated thickness that is required to sustain the loads. The nominal value should be smaller than the nominal design thickness.
Reinforcement limit header direction – W_max: Length from the branch outside diameter to the end of the header reinforcement zone.
Reinforcement limit branch direction – H_max: Length from the header outside diameter to the end of the branch reinforcement zone.
Material area header – A₀: Cross-sectional area of header material between reinforcement limits.
Material area branch – A₁: Cross-sectional area of branch material between reinforcement limits.
Material area of extra added reinforcement including welds – A₂: Cross-sectional area of reinforcement material between reinforcement limits.
Total available material area – A: Total cross-sectional area of material between reinforcement limits. Sum of areas is corrected for stress ratios.
Total pressure area – A_p: Total cross-sectional area with pressure in header and branch between reinforcement limits.
Strength reduction coefficient at opening – z₃: Effectiveness of the strength in the opening.
Maximum Allowable Working Pressure – MAWP: The maximum pressure at which the component can be used in operation. This value should be larger than the design pressure.
Design margin – DP/MAWP: Ratio of the design pressure to MAWP
Maximum Allowable Test Pressure – MATP: The maximum pressure at which the component should be tested and survive.
Tapering header and branch: The tapering of the header and branch on connecting pipes is checked.

Scope errors

Design pressure is out of scope: minimum operating pressure > 16 bar.: This code determines a minimum pressure.
Design temperature is out of scope: required -40 °C ≤ T ≤ 120 °C.: This code determines a minimum and maximum temperature.
Design factor is too large: required is fo ≤ fo_max (see 7.2).: This code determines a maximum design factor.
Wall thickness header is out of scope according paragraph 7.9.2 Table 1.: This code determines for headers a minimum thickness.
Wall thickness branch is out of scope according paragraph 7.9.2 Table 1.: This code determines for branches a minimum thickness.
Angle branch is out of scope (center line branch to header wall): required is 45° ≤ α ≤ 135°.: This code determines a minimum and maximum branch angle.
Angle branch is out of scope (center line branch to header wall): required is 45° ≤ γ ≤ 90°.: This code determines a minimum and maximum branch angle.

Errors

Can’t find material ‘MaterialName’ in database: Material could not be found in database. Select an existing material name, or select another material via the material selection window.
Insufficient wall thickness for header: Wall thickness is insufficient to bear the applied loads. Increase the wall thickness.
Insufficient wall thickness for branch: Wall thickness is insufficient to bear the applied loads. Increase the wall thickness.
Insufficient reinforcement: required is z₃ ≥ z_min.: Reinforcement area is too small. Increase the reinforcement width or wall thickness of reinforcement, header or branch.

Warnings

Tapering header in reinforced zone.: Indicates tapering of header in reinforced zone.
Tapering branch in reinforced zone.: Indicates tapering of branch in reinforced zone.