Document: NUREG-0800
Document ID: 217aa53e-c4ac-4a8f-b1b6-968ad75d68ab
Document Type: srp
Title: INSERVICE TESTING OF PUMPS AND VALVES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070368.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.6
CFR Part: 
CFR Title: 

Content:
mmon Motor-Operated Valve Deficiencies, Misadjustments, and Degraded Conditions • Incorrect torque switch bypass settings • Incorrect torque switch settings • Unbalanced torque switch • Spring pack gap or incorrect spring pack preload • Incorrect stem packing tightness • Excessive inertia • Loose or tight stem-nut locknut • Incorrect limit switch settings • Stem wear • Bent or broken stem • Worn or broken gears • Grease problems (hardening, migration into spring pack, lack of grease, excessive grease, contamination, nonspecified grease) • Motor insulation or rotor degradation • Incorrect wire size or degraded wiring • Disk/seat binding (includes thermal binding) • Water in internal parts or deterioration therefrom • Motor undersized (for degraded voltage conditions or other conditions) • Incorrect valve position indication • Misadjustment or failure of handwheel declutch mechanism • Relay problems (incorrect relays, dirt in relays, deteriorated relays, miswired relays) • Incorrect thermal overload switch settings • Worn or broken bearings • Incorrect torque or limit switch installed (inside and outside containment applications) • Broken or cracked limit switch and torque switch components • Missing or modified torque switch limiter plate • Improperly sized actuators • Hydraulic lockup • Incorrect metallic materials for gears, keys, bolts, shafts, etc. • Degraded voltage (within design basis) • Defective motor control logic • Excessive seating or backseating force application • Incorrect reassembly or adjustment after maintenance and/or testing • Unauthorized modifications or adjustments • Torque switch or limit switch binding • Pressure locking of gate valves128 SRP Draft Section 3.9.6 Attachment A - Proposed Changes in Order of Occurrence 3.9.6-23 DRAFT Rev. 3 - April 1996 Item numbers in the following table correspond to superscript numbers in the redline/strikeout copy of the draft SRP section.