Input variables

Generic variables

These variables can be found in mostly 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 – DP

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

Design Temperature – θ

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 (tapered) header and (tapered) branch – D, D′, D₂, D₂′: 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 (tapered) header and (tapered) branch – T_n, T_n′, T_2n, T_2n′: Thickness ‘as is’, meaning it is the design thickness taking into account corrosion and tolerance.
Tapered section: Section in which the thickness of either the branch or header gradually changes to the thickness of the pipe.
Corrosion – Ca: Amount of thickness that accounts for the possible effects of corrosions.
Tolerance – tol: Tolerance in thickness for production
Strength reduction coefficient – z: Effectiveness of the strength, depending on whether joints are seamless, welded, or expected to perform worse than the base material properties
Half width header direction – W₀: Distance from the centerline of the branch part to the end of the header part indicated by the direction.
Half height branch direction – H₀: Distance from the centerline of the header part to the end of the branch part indicated by the direction.
Crotch outside radius factor – R_f: Tee transition outside radius factor. Default value is 0.67
Crotch thickness factor – C_F: Tee crotch thickness factor. Default value is 1.25
Tee transition outside radius header to branch – R: Tee crotch outside radius. Radius is calculated or user defined.
Nominal Crotch Thickness – T_cn: Crotch thickness is calculated or user defined.

Tee dimensions

Calculated Values

Allowable Operating Stress – S: Stress in the component at which it is still allowed (without failure) to use the component
Allowable stress at 20 °C – S_t: Stress in the component at which it is still allowed (without failure) to use the component at 20 °C ambient temperature
Header inside diameter at the reinforcement limit – D_i^*: Inside diameter of the header where the header meets the outside diameter of the branch at the reinforcement limit.
Header thickness at the reinforcement limit – T^*: Thickness of the header where the header meets the outside diameter of the branch at the reinforcement limit.
Branch inside diameter at the reinforcement limit – D_i2^*: Inside diameter of the branch where the branch meets the outside diameter of the header at the reinforcement limit.
Branch thickness at the reinforcement limit – T₂^*: Thickness of the branch where the branch meets the outside diameter of the header at the reinforcement limit.
Reinforcement limit header direction – L: Length from the branch outside diameter to the end of the header reinforcement zone.
Reinforcement limit branch direction – H: Length from the header outside diameter to the end of the branch reinforcement zone.
Total available material area – A: Total cross-sectional material area in tee between reinforcement limits.
Total pressure area – A_p: Total cross-sectional area with pressure in tee between reinforcement limits.
Pressure force – F_p: Total force of the design pressure on the total pressure area.
Maximum allowable pressure force – F_pmax: Maximum allwable force of the design pressure on the total pressure area.
Minimum strength coefficient reduction at opening – z_min: Minimum required effectiveness of the strength in the opening.
Strength reduction coefficient at opening – z: 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.

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 of the header.
Insufficient wall thickness for branch: Wall thickness is insufficient to bear the applied loads. Increase the wall thickness of the branch.
Insufficient reinforcement area or wall thickness.: Reinforcement area is too small. Increase the reinforcement area or thickness.
Insufficient strength reduction coefficient for tee: required is z ≥ z_min: Strength reduction coefficient is too small. Increase the reinforcement area or thickness.

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.

Remarks

Branch thickness is large, maximum used in calculation is twice the header thickness.: This code determines for branches a maximum thickness.
Branch thickness tapering is large, maximum used in calculation is twice the tapered header thickness.: This code determines for branches a maximum thickness.