ENS 51260
ENS Event | |
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04:00 Jul 24, 2015 | |
Title | Part 21 - Actuator Shaft Did Not Meet Dimensional Requirements |
Event Description | The following information was excerpted from a facsimile provided by Flowserve:
In accordance with the provisions of 10CFR Part 21, [Flowserve] has identified a potential issue and is submitting our evaluation of the event. DESCRIPTION: Energy Northwest - Columbia Station reported a replacement actuator shaft for 6-900 Anchor/Darling swing check was different than the one removed and could not be installed. After consultation with Flowserve, it was determined the actuator shaft did not meet the dimensional requirements of the manufacturing drawing. The shaft includes an off-set lug that engages the hinge and allows testing or exercising the valve disc. The shaft diameter opposite the lug was too large but must be equal to or less than the basic diameter adjacent to the lug in order to allow free disc swing. SCOPE: Replacement actuator shafts supplied by Flowserve using manufacturing drawings that do not definitively specify the radius/diameter at the lug. Applies to Anchor/Darling swing check valves with levers or actuators. PROPOSED ACTION: Flowserve will revise actuator shaft drawing to clearly define the radius/diameter at the lug. Flowserve will notify the customers of the attached evaluation of the defect and will request that the actuator shafts be returned to Flowserve for evaluation and/or replacement at no charge. SUBJECT: Actuator Shaft supplied for 6-900 Exercisable Swing Check Valve, Drawing No. 3489-3 manufactured by Anchor/Darling Valve Co. and installed at Energy Northwest (ENW) - Columbia Station. ROOT CAUSE: The actuator shaft was machined by a Flowserve subvendor which incorrectly interpreted the machining drawing and produced the shaft with a large, out of tolerance radius around the lug. The drawing was not clear to the subvendor. Flowserve inspection did not discover the discrepancy during subsequent dimensional inspection. POTENTIAL EFFECT: An excessively large diameter at the lug will not allow installation of a replacement actuator shaft. A shaft with a diameter opposite the lug that is greater than design but still small enough to allow installation could retard or prevent free disc swing and adversely affect check valve function. EVALUATION: Swing check valves normally operate automatically reacting to fluid flow and do not include external operating mechanisms. Some valves include external mechanisms to confirm valve operation using an external lever or actuator to cycle the disc. Normally these check valves are allowed to swing freely and the external mechanism is not engaged. The external mechanism is only engaged for testing or exercising. The engagement is accomplished by a lug on the actuator shaft that rides in a cut out in the hub of the hinge. The hinge rotates on the actuator shaft during normal, free operation therefore the clearance between the hinge hub bore and shaft is a critical design feature and can affect operation. Proper operation of valve assemblies are verified during production testing therefore are not within the scope of this evaluation. CONCLUSION: Although the ENW actuator shaft could not be installed due to the excess material, inadequate removal to allow installation could affect the function. In addition shafts manufactured to similar manufacturing drawings supplied as replacement parts could be capable of installation but not allow complete free disc / hinge swing. Affected plants include Exelon - Limerick, Exelon - Quad Cities, and Energy Northwest - Columbia. |
Where | |
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Flowserve Corporation Raleigh, North Carolina (NRC Region 1) | |
Organization: | Flowserve Corporation |
Reporting | |
10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
Time - Person (Reporting Time:+0.92 h0.0383 days <br />0.00548 weeks <br />0.00126 months <br />) | |
Opened: | Michael Roy 04:55 Jul 24, 2015 |
NRC Officer: | Jeff Rotton |
Last Updated: | Jul 24, 2015 |
51260 - NRC Website | |
Flowserve Corporation with 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
WEEKMONTHYEARENS 512602015-07-24T04:00:00024 July 2015 04:00:00
[Table view]10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 - Actuator Shaft Did Not Meet Dimensional Requirements ENS 512622015-07-24T04:00:00024 July 2015 04:00:00 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 - Mounting Bracket Seismic Qualification 2015-07-24T04:00:00 | |