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AMS Superconducting MagnetBurst Disc Testing

April 2007

Steve HarrisonScientific Magnetics

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The AMS magnet has vessels and potential trapped volumes protected by burst discs.

The qualification procedure for the burst discs was agreed with the PSRP in November 2003 (Trent Martin).

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“To supply two bursting discs for the flight or STA systems, six burst discs must be manufactured. All six discs will be identical and four of the six will be vibrated at operating temperature and then burst. Data will be recorded to show bursting temperature and pressure for each qualification disc burst.Assuming the four discs tested have been acceptable the remaining two will then be considered flight qualified.”

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The design of the discs was also agreed with the NASA Safety Panel.Reverse-buckling bladed discs were not preferred for liquid service as they may not open fully.

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The burst discs are reverse-buckling with a peripheral score and cutting teeth in the vent ring. It was agreed that this design is intrinsically single-fault tolerant.

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Prototype discs were deliberately burst at ambient and cryogenic temperatures …

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… before and after vibration testing.

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Qualification discs are all vibration tested then deliberately burst. Both vibration and burst tests are undertaken at the operating temperature of the disc.Nearly all the flight discs have been completed.

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BD05 type ambient temperature burst disc (10 bar).

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BD06 type ambient temperature burst disc (2 and 3 bar double unit).

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BD03 cryogenic burst discs ready for cryogenic vibration test.

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BD03 cryogenic burst test just completed.

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BD03 cryogenic burst discafter burst test.

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Test #

Burst Temperatur

e (K)

Burst Pressure

(bar)1 2.47 2.88

2 2.37 2.89

3 3.41 2.95

4 3.00 2.88

5 2.40 2.97

6 2.51 2.92

BD03 type cryogenic burst disc(3 bar +0/-10%).

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BD02 cryogenic burst disc and test insert.

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Test #

Burst Temperatur

e (K)

Burst Pressure

(bar)1 4.6 18.8

2 3.3 19.2

3 2.9 18.8

4 3.0 19.2

5 3.0 19.4

6 3.7 19.1

BD02 type cryogenic burst disc(20 bar +0/-10%).

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Manufacture and qualification of ambient temperature and cryogenic burst discs is nearly complete. All discs have burst within the specified limits.