Construction Code

Use the drop down box to select the construction code that was used. Div. 1 may be selected for equipment constructed to ASME Section I (Power Boilers), but it should be noted that the equipment was constructed to ASME Section I. 

MAWP or Design Pressure

Enter the Maximum Allowable Working Pressure (MAWP) in the pressure units selected. If the MAWP is not available from the documentation, enter the design pressure.

Design Temperature

Enter the design temperature for the vessel. This value is used for all components. The design temperature is recorded for information only at this time. However, a MAT credit for vessels with high enough design temperatures resulting in a reduction in the allowable stress may be provided in future versions.

Critical Exposure Temperature (CET)

The CET is defined as the lowest metal temperature, where both operating and atmospheric conditions are considered. The atmospheric conditions should consider the maximum credible coincident pressure-temperature and supplemental loads combination that results in general primary stresses greater than 8 ksi/55 MPa.

Operating conditions should consider startup, shutdown, upset and standby conditions. See [1] Paras 3.1.5 and 3.3.3 for a full description of the process and ambient factors which should be considered in arriving at the CET. 

Design Corrosion Allowance Original

Enter the original design corrosion allowance. If unknown, enter zero.

Take Credit for Future Corrosion Allowance?

Select whether the assessment should take credit for future corrosion allowance.

Future Corrosion Allowance

Enter the future corrosion allowance. This value plus the previous metal loss value should be less than or equal to the original design corrosion allowance.  If current corrosion data is not available, then it is recommended to set the future corrosion allowance equal to the design corrosion allowance.

This value is only visible if user elects to take credit for future corrosion allowance.

Previous Metal Loss

Enter the previous actual measured (or estimated) metal loss due to corrosion.  This value plus the future corrosion allowance should be less than or equal to the original design corrosion allowance.  If a value is not available, then enter zero.

This value is only visible if user elects to take credit for future corrosion allowance.

Consider hydrotest condition (Level 2 Method B)?

Select whether to consider hydrotest condition (Level 2 method B).

Hydrotest Temperature

Enter the temperature that corresponds to the hydrotest pressure value.  If unknown, a conservative estimate of the highest credible temperature may be entered. In this case, a MAT based on hydrotest will not be calculated. If a hydrotest has been conducted at a lower temperature than the temperature corresponding to the highest previous hydrotest, the lower temperature and corresponding lower hydrotest pressure may be entered. It is acceptable to use a trial and error process to determine which of the previous hydrotest pressure/temperature combinations give the most favorable result.

This value is only visible if the user elects to consider the hydrotest condition.

Hydrotest Pressure

Enter the hydrotest pressure in the selected units. This should be the highest of the original and subsequent field hydrotest pressures, except as noted above.

This value is only visible if the user elects to consider the hydrotest condition.

Consider past operating experience (Level 2, method C)

Select whether to consider past operating experience (Level 2, method C).

Pressure

Enter the pressure corresponding to the 'worst case' combination of pressure and temperature experienced by the vessel in service.

This value is only visible if the user elects to consider past operating experience.

Temperature

Enter the temperature corresponding to the 'worst case' combination of pressure and temperature experienced by the vessel in service.

This value is only visible if the user elects to consider past operating experience.

Equipment is not subject to shock chilling or environment cracking

Select if the shock chilling (see para 3.3.3.e and Figure 3.2 for definition) or environmental cracking are not credible. This is required to proceed with the brittle fracture analysis, Level 2 method C and is only visible if this option is selected.

Operating conditions have been consistent with design for a significant period of time?

Select if this is the case. This is required to proceed with the brittle fracture analysis,  Level 2 method C and is only visible if this option is selected.

Cyclic loading is not a controlling factor

Select if loading is not a controlling factor. This is required to proceed with the brittle fracture analysis, Level 2 method C and is only visible if this option is selected.

Compute stress ratio (Rts) using design corrosion allowance

Select if nominal thickness and design corrosion allowance are to be used in lieu of minimum required thickness in Eqn 3.2 when minimum required thickness is not entered for a given component.