Summary

• What is the maximum allowable specified burst pressure?

- Design Pressure or MAWP if the rupture disk is the only relief device

OR

- For special cases, 105% (or even 110%) of design pressure or MAWP if the rupture disk is a secondary device

 

• What should be the expected stamped (rated) burst pressure of the rupture disk?

- As specified by the process engineer for a Manufacturing Range of ± 0%

OR

- As specified by the process engineer but could be adjusted per the Manufacturing Range if other than ± 0%

• At what pressure(s) can we expect the delivered rupture disk to actually burst at?

- ± 5% of stamped burst pressure for stamped pressures greater than 40 psig

OR

- ± 2 psi for stamped pressures 40 psig and lower

• What is the maximum allowable operating pressure in the vessel?

- Specified by the process engineer based on operating need but must be checked against the Operating Ratio of the rupture disk
- I strongly suggest you also check against the minimum expected burst pressure as well.

• Manufacturing Range is applied to the specified burst pressure
• Burst Tolerance is applied to the stamped burst pressure
• Set the design pressure appropriately
• Choose a rupture disk with a MR of ± 0%
• Choose a rupture disk with a OR of 90%

References

1. API (www.api.org) Recommended Practice 520, "Sizing, Selection, and Installation of Pressure-Relieving Device in Refineries, Part 1-Sizing and Selection", 7^th Edition (January 2000)
2. API (www.api.org) Recommended Practice 521, "Guide for Pressure-Relieving and Depressuring Systems", 4^th Edition (March 1997)
3. ASME (www.asme.org) "Boiler and Pressure Vessel Code, Section VIII, Division 1" (1998)
4. Continental Disc Corporation, ULTRX ^® Catalogue 3-2210-3