code mandates that two rupture discs per lot are the minimum requirements to make a batch of discs which some manufacturers adhere to. CDC however go above and beyond the ASME code with their unique lot qualification testing.
For example the “simulated in-plant use test” is the only way to offer a guarantee to the client that the disc will work for their application.
ULTRX® Scored Reverse Acting Continental Rupture Disc (Bursting Disc) Lot Qualification and In-house Testing Procedures
ULTRX rupture discs (bursting discs) are manufactured and tested under a Quality Assurance Program certified to ISO 9001 Quality System requirements. Before any lot of ULTRX rupture discs are shipped from Continental Disc Corporation, specific criteria must be met. Following is a listing of qualification procedures and tests required for each lot.
Any bursting disc which fails any test or inspection at any stage during manufacture, causes total lot rejection. The lot of rupture discs is scrapped, remanufactured and each step or test listed below is repeated. There are NO MARGINAL RUPTURE DISCS, NO SECONDS, and in TOTAL QUALITY, no room for error.
1) Liquid Penetrant Test – A liquid penetrant test is conducted on each rupture disc to verify the score integrity.
2) Destructive Burst Test – To verify non-fragmentation, an air volume burst test, to destruction, is conducted on one rupture disc from the manufactured lot.
3) Destructive Burst Test – One rupture disc from the lot is intentionally damaged. This rupture disc is then burst under air pressure to verify the damage safety ratio.
4) Destructive Burst Test – Two rupture discs from the lot are intentionally damaged. Under hydraulic pressure, both rupture discs are burst tested to verify the damage safety ratio in liquid service.
5) Destructive Burst Test – A minimum of two rupture discs are burst tested at ambient temperature as required by ASME Code Section VIII and Continental Disc Corporation’s internal testing standard.
6) Destructive Burst Test – Two rupture discs are burst tested at elevated temperature as required by ASME Code Section VIII.
7) Simulated In-Plant Use Test – One rupture disc is pressurised with 30 psig pressure on the concave side. This rupture disc is cycled from 0 to 90% of the ambient rating (plus 30 psig) against the convex side for a minimum of 1000 cycles, followed by a liquid penetrant test of the rupture disc score line. This is to simulate in-plant use and verify score line integrity.
8) Proof Pressure Test – All remaining rupture discs in the lot, comprising the shipment quantity, are proof pressure tested to 90% of the ambient temperature rating to verify each rupture disc’s ability to withstand the maximum operating pressure recommended by Continental disc Corporation.
9) Final Production Stage:
a) Cleaning the finished rupture discs.
b) Tagging per customer requirements on Continental Disc’s exclusive three-dimensional tag. Tagging includes KR, MNFA, and UD Code Symbol Stamp when ASME Section VIII is specified.
c) Completion of a burst test certificate for enclosure with shipment.
Final inspection by Quality Assurance is independent of production. It is performed 100% and includes verification of all test results for conformance, rupture disc physical appearance, documentation review and packaging inspection.
ULTRX holders have been similarly design tested and are 100% inspected for dimensional characteristics and appearance by Quality Assurance inspectors. Continental Disc Corporation provides permanently affixed Stainless Steel Customer Identification Tag when equipment tag numbers are furnished on the order.