Text

NRC MOV Training April 2019 Day 1 Part 2 Public Version
	ML19235A126
Person / Time
Issue date:	08/23/2019
From:	Michael Farnan, Eric Thomas; NRC/NRR/DIRS/IRIB
To:	;
	Thomas E, 415-6772, NRR/DIRS
References
	Download: ML19235A126 (104)
	v • d • e

Rotor Failure Mechanism -

Overheating and Galvanic Corrosion 130 FIGURE REDACTED

Rotor Failure Mechanism - Overheating and Galvanic Corrosion (continued) 131 FIGURE REDACTED

Rotor Failure Mechanism - Overheating and Galvanic Corrosion (continued) 132 FIGURE REDACTED

Rotor Failure Example - 1 133 PHOTO REDACTED

Rotor Failure Example - 2 134 PHOTO REDACTED

Rotor Failure Example - 3 135 PHOTO REDACTED

Rotor Failure Example - 4 136 PHOTO REDACTED

Rotor Failure Example - 5 137 PHOTO REDACTED

Rotor Failure - Overheating 1 138 PHOTO REDACTED

Rotor Failure - Overheating 2 139 PHOTO REDACTED

Rotor Failure - Overheating 3 140 PHOTO REDACTED

Rotor Failure - Overheating 4 141 PHOTO REDACTED

Rotor Failure - Overheating 5 142 PHOTO REDACTED

Industry Motor Rotor Degradation Preventive Measures

Review MOV program and identify motors that could have rotors constructed of magnesium.

Upgrade motor from magnesium rotor to aluminum rotor design.

Add motor inspection ports, if needed.

Implement periodic motor internal inspection program using borescope technology and/or motor disassembly.

Implement new motor rotor inspection upon receipt.

143

Preventive Measures - Borescope 1 144 PHOTOS REDACTED

Preventive Measures - Borescope 2 145 PHOTO REDACTED

Preventive Measures - Borescope 3 146 PHOTO REDACTED

Preventive Measures - Borescope 4 Clearance between Rotor & Stator Example of a good motor 147 PHOTO REDACTED

Preventive Measures - Borescope 5 Motor Shaft Iron Fin Corrosion Deposits 148 PHOTO REDACTED

Preventive Measures - Borescope 6 Motor Shaft FIN Iron Motor Key Corrosion 149 PHOTO REDACTED

Preventive Measures - Borescope 7 Motor Shaft Fin Iron Separation 150 PHOTO REDACTED

NRC and Industry Actions on Motor Rotor Degradation NRC Information Notices 1986-02, 2006-26, and 2008-20 NRC staff discussed topic with INPO, NEI Licensing Action Task Force, ASME OM Code Committee, MOV Users Group, IST Owners Group, BWROG, and PWROG Vendor technical bulletins: GE SIL 425 (1985) and Limitorque Technical Update 06-01 (2006)

BWROG Valve Technical Resolution Group developed technical guideline for motors with magnesium rotors that provides inspection criteria, priority, disassembly and re-coating procedures.

PWROG uses applicable guidance in BWROG document.

151

Motor Jogging

During MOV testing in response to GL 89-10, many motors were damaged by repetitive testing without adequate cooling periods between motor starts.

In a letter dated July 29, 1993, Limitorque recommended that 3-phase AC motors and DC motors be limited to 5 consecutive starts with cooling periods before restarting based on motor frame size as follows:

Frame 48 (1 hr), 56 (1.5 hr), 182 (2 hr), 184 (2.5 hr), and 215 (3 hr).

Licensees should be aware of the potential for motor damage where sufficient cooling periods are not provided between motor starts.

Cooldown periods are typically exponential and dependent on motor frame size, winding type, and insulation.

152

MOV Grease Discussion

Hardened grease can affect MOV operations

March 12, 2009, Peach Bottom - Valve failed mid-stroke during line up for test

March 21, 2009, Peach Bottom - Valve failed to fully open during surveillance test

March 30, 2009, Vogtle - Valve stroked full open but failed to close

August 5, 2009, Vogtle - Valve failed as found close test during Viper PM

IFR 2009-009 initiated to evaluate issue 153

Limitorque Actuator Grease Areas

Main Gear Box

Stem / Stem Nut

Limit Switch Upper/Lower Gear Frames & Intermittent Gear Cartridge Assembly 154

Stem Nut is threaded onto stem until splines mate up with drive sleeve assembly.

Lock nut is threaded into drive sleeve assembly to maintain Stem Nut in place.

155 FIGURE REDACTED

Limitorque Valve Actuator Secured to Valve Yoke Grease is added to main gear box and applied to stem threads. The main gear box is filled to a level that covers the worm gear. This is approximately 75%.

156 FIGURE REDACTED

Upper and lower gear frames are filled to about 80%

with grease -

enough to cover gear trains 157 FIGURE REDACTED

Limitorque Actuator Grease Recommendations

Routine check every 18 months minimum. Frequency can increase based on frequency of operation and ambient environment conditions.

Clean and lubricate valve stem in accordance with valve manufacturers lubricant recommendation.

For nuclear applications, Exxon Nebula EP-0 & EP-1 and Crompton MOV Long Life Grade 0 (27 year installed life) were only approved lubricants for actuator gear case.

Exxon Nebula grease is now obsolete for MOV use with licensees switching to MOV Long Life.

158

Limitorque Actuator Grease Recommendations (continued)

Ensure that actuator has enough lubricant in gear case to completely immerse worm and worm gear.

Typical inspection interval for main gearcase grease is 6 years to determine whether replacement is necessary.

Geared Limit Switch uses Mobil 28 grease.

Motors furnished for Limitorque actuators have motor bearings that are lubricated for life.

159

Toutput d(0.96815 tan + µ)

=

Thstem 24(0.96815 - µ tan )

Toutput

=

Output torque of valve actuator (foot-pounds)

Thstem

=

Valve stem thrust (pounds force) d

=

ODstem - 1/2 Pitch tan

=

Lead / (d)

µ

=

Stem / Stem Nut coefficient of friction ODstem

=

Outside diameter of stem (inches)

Pitch

=

Distance from peak of one thread to peak of an adjacent thread (inches / thread)

Lead

=

Distance stem travels in one revolution of Stem Nut (inches / revolution)

Where:

Power Screw Equation 160 SF =

161 Stem Threads FIGURE REDACTED

Power Screw Equation

Equation is based on standard Acme thread design.

The only variable in power screw equation is Stem to Stem Nut coefficient of friction (µ).

Ratio of torque to thrust is known as Stem Factor.

162

Stem / Stem Nut Interface Facts

EPRI testing confirmed that clean, lubricated Stem /

Stem Nut yielded stable coefficient of friction (COF) factors equal to or less than 0.15

EPRI establishes 0.20 Stem Nut COF as bounding upper value

Stem Nut COF can be much lower than 0.15 163

Stem / Stem Nut Interface Facts (continued)

Valve stems typically are pre-lubricated from manufacturer with Never Seize type product.

Never Seize products consist of solids in volatile solvent, oil, resin or grease carrier.

Limitorque has found poor results from Never Seize products when used on valve stem.

Historical testing of Never Seize type products yield that COF factors can fluctuate.

164

Stem / Stem Nut Interface Facts (continued)

Valve stem threads to fit Stem Nut are cut usually on a lathe using standard Acme Left Hand Thread Design

Stem Nut is Married to the Stem. The threads are cut via lathe or tap

Although both Stem and Stem Nut are cut to standard Acme Thread design, many do not fit on first cut pass due to manufacturing tolerances. It is sometimes necessary to take off a few thousands on Stem Nut in order to match the threads.

This is one reason why COF factors can vary from valve to valve.

165

Safety Significance of Stem Nut COF

High COF yields less thrust force on valve stem with same actuator input torque.

Valves set with low margins run risk of not being able to perform their safety-related function should COF increase over time or with operation.

Low COF yields more stem thrust from same actuator output and torque switch trip that can exceed weak link assumptions.

166

Stem Lube Degradation Operating Experience

REDACTED 167

Stem Lube Degradation Contributing Factors

Incorrect grease for application.

Stem cleaning and lube preventive maintenance (PM) intervals are being extended without data to support.

Stem cleaning and lube PM not being performed properly.

Poor feedback from maintenance personnel on actual as found grease condition.

Ineffective corrective action process.

Available industry information not effectively applied.

Environmental changes not factored into PM program.

Cross contamination of greases can accelerate grease degradation.

168

4.b Testing experience 169

Generic Issue 87

NRC sponsored valve testing program by Idaho National Laboratory (INL) to evaluate Generic Issue 87, Failure of HPCI Steam Line Without Isolation

Phase 1 (1988): Valve flow testing at Wyle including: inch Anchor/Darling FWG inch Velan FWG

Phase 2 (1989): Valve flow testing at Karlstein FRG including: inch Anchor/Darling FWG inch Velan FWG inch Walworth FWG inch Anchor/Darling FWG inch Powell FWG inch Velan FWG 170

NRC-Sponsored INL Research

Valve flow performance

AC-powered MOV output

DC-powered MOV output

Stem friction coefficient

Temperature effects

Actuator efficiency

Valve aging 171

INL Test Stand 172 PHOTO REDACTED

INL MOV Research Reports NUREG/CR-5406 (10/1989) - Gate Valve Flow Tests NUREG/CR-5558 (1/1991) - Gate Valve Flow Tests NUREG/CR-5720 (6/1992) - MOV Research Update NUREG/CR-6100 (9/1995) - Gate Valve & Operator NUREG/CR-6478 (7/1997) - Actuator Motor and Gearbox NREG/CR-6611 (5/1998) - Pressure Locking NUREG/CR-6620 (5/1999) - DC-Powered MOVs NUREG/CR-6750 (10/2001) - Stem Lubricant Performance NUREG/CR-6806 (9/2002) - Stem Lubricant Aging NUREG/CR-6807 (3/2003) - Stellite Aging 173

Industry Testing

Electric Power Research Institute (EPRI) developed test-based valve performance methodology.

Joint Owners Group (JOG) developed MOV dynamic testing program in response to GL 96-05.

ComEd conducted motor output study.

BWROG developed DC motor actuator output methodology.

174

EPRI MOV Performance Prediction Program

Test-based methodology for predicting operating requirements for gate, globe, and butterfly valves described in EPRI TR-103237 (Rev. 2, 1997).

NRC accepted EPRI MOV PPM with conditions in SE (3/15/96) with supplements:

- Supplement 1 (2/20/97) accepted EPRI PPM hand-calculation methods for two additional valve designs

- Supplement 2 (4/20/01) accepted modeling improvements in PPM Addendum 1

- Supplement 3 (9/30/02) accepted thrust uncertainty method in PPM Addendum 2

- Supplement 4 (2/24/09) accepted various PPM improvements in PPM Addenda 3 to 7.

175

NRC SER Conditions

SER specified the following conditions on use of the EPRI MOV PPM by licensees:

- Unwedging data need to be evaluated.

- Internal valve preventive maintenance program needed.

A documented engineering analysis of valves that have been determined to have no degradation will not require an internal examination.

- Cannot extrapolate to blowdown conditions from pump flow conditions.

- Licensee is responsible for actuator output.

- Uncertainties need to be addressed.

176

EPRI MOV Guides

EPRI MOV Application Guide TR-106563:

- Volume 1: Gate and Globe valves

- Volume 2: Butterfly valves.

EPRI Technical Repair Guidelines NP-6229 (SMB-000) and NP-6631 (SMB-00).

EPRI guides provide significant information on MOV design, operation, and lessons learned, including EPRI MOV testing program.

177

JOG Program on MOV Periodic Verification

Risk-informed program to share test information on valve operating requirements for responding to GL 96-05.

5-year dynamic testing of sample MOVs at each participating plant.

Static and dynamic testing based on program results and margin.

Test frequency based on risk and margin.

NRC accepted in SE dated September 2006.

RIS 2011-13 indicates licensees may implement ASME OM Code Appendix III or Code Case OMN-1 for JOG Class D valves outside scope of JOG program.

178

JOG Program Highlights

JOG addressed gate, globe, and butterfly valves.

JOG did not identify any significant aging issues with tested valves after reaching their valve factor plateau.

JOG did not test a sufficient number of valves to establish a valve factor database.

JOG did not address actuator output.

179

ComEd MOV Output Methodology

In 1990s, ComEd tested motors to evaluate output capability and degraded voltage factors.

ComEd evaluated test data from other sources for actuator performance.

ComEd White Paper 125 (Rev. 3, 2/8/99) provides methodology for sizing motor actuators.

NRC staff accepted use of ComEd White Paper 125 during GL 89-10 inspections.

Exelon preparing update to White Paper 125 180

White Paper 125 Highlights

Higher motor output than nameplate for some motors.

Degraded voltage ratio for some ac motors greater than squared term.

Margin factor necessary when applying White Paper 125 method.

ComEd White Paper 125 will predict more or less output than Limitorque equation depending on the specific motor and its application.

181

BWROG DC MOV Methodology

Based on research identifying effects on DC MOV output from temperature, voltage, and loading, BWROG developed updated methodology for DC MOV output and stroke time.

BWROG used vendor motor curves and test data from INL and industry sources in developing its methodology.

BWROG indicated that methodology would be made available to PWR licensees.

NRC discussed BWROG methodology in RIS 2001-15.

182

BWROG DC MOV Methodology Highlights

BWROG method solves for output and stroke time for each stroke increment.

BWROG method calculates:

- Capability margin

- Maximum allowable thrust at TS trip and unwedging

- Stroke time

BWROG used data from only 7 MOVs.

As discussed in RIS 2001-15, NRC considered BWROG methodology acceptable but noted limited data.

183

RIS 2001-15 Performance of DC-Powered Motor-Operated Valve Actuators

Alerted licensees to updated methodology developed by BWROG to evaluate capability of DC-powered MOVs to perform their safety functions.

Based on INL sample testing, NRC staff considered BWROG methodology to represent a reasonable approach in improving past industry guidance for predicting DC-powered MOV output.

Noted BWROG recommended schedule for BWR licensees to implement methodology.

Indicated that methodology also applicable to DC-powered MOVs in PWR plants.

184

5. MOV Performance and Design Analysis 185

Overview

a. Differential pressure and flow conditions

b. Valve operating requirements

c. Motor actuator output capability

d. Uncertainties

e. Margins f.

Weak link analysis

g. Example calculations 186

5.a Differential pressure and flow conditions 187

Differential pressure and flow assumptions

During GL 89-10 implementation, licensees re-evaluated design-basis differential pressure and flow assumptions for safety-related MOVs.

Westinghouse and GE provided assistance in updating differential pressure and flow assumptions.

Licensees should rely on updated differential pressure and flow assumptions developed as part of GL 89-10 programs.

If not available, licensees should rely on UFSAR provisions.

188

5.b Valve operating requirements 189

ASME Standard QME-1-2007 qualification program (RG 1.100)

EPRI MOV PPM calculation

EPRI MOV Application Guide TR-106563 (Volume 1)

Plant-specific test data

Vendor or industry test data where justified 190 Gate and Globe Valve Operating Requirements

Gate valve thrust operating requirements REDACTED 191

Differential pressure force REDACTED 192

Stem piston effect FPE = As

P where As = valve stem area P = system pressure Sealing load (FS)

- see EPRI method 193

Globe valve thrust operating requirements REDACTED 194

Required Actuator Output Torque (Gate and Globe)

RO TOR = RVTHR

SF where SF = stem factor based on stem diameter, thread pitch and lead, and stem friction coefficient 195

Stem Factor Calculation for ACME threads SF = d (0.96815 tan + µ)

24 (0.96815 - µ tan )

where tan = Stem lead

d d = Ds - Pitch 2

TPI = Stem threads per inch Pitch = 1 TPI Lead = Pitch

Thread type (single, double, triple)

µ = Stem to Stem Nut friction coefficient DS = Stem diameter 196

Butterfly valve torque operating requirements

- ASME Standard QME-1-2007 qualification program (RG 1.100)

- EPRI MOV PPM calculation

- Plant-specific test data

- Vendor or industry test data where justified

- EPRI MOV Application Guide TR-106563 (Volume 2) 197

Butterfly Valve Operating Torque (EPRI)

REDACTED 198

5.c Motor actuator output capability 199

AC Motor Actuator Capability (Gate and Globe)

(Limitorque Technical Update 98-01, S1)

ACTTOR = MT

Eff

AF

OAR

Temp

VMIN n

VRAT ACTTHR = ACTTOR SF where ACTTOR = motor actuator output torque capability ACTTHR = motor actuator output thrust capability MT = motor rated torque VMIN = minimum voltage at motor VRAT = rated motor voltage If voltage drop > 10%, n = 2 (but n = 0 if 10%)

Eff = pullout efficiency AF = application factor OAR = overall actuator ratio Temp = temperature degradation factor (Limitorque TU 93-03) 200

Degraded Voltage Considerations

- No degraded voltage factor (n=0) if voltage drop less than or equal to 10% because motor design with application factor (typically 0.9) compensates for up to 10% reduced voltage.

- Degraded grid relay setpoint should be used as the starting point for calculating the minimum voltage at the motor terminals.

- Supplement 1 to GL 89-10 provides guidance for the voltage reduction calculation with in-rush or locked rotor current.

201

DC Motor Actuator Capability (Gate and Globe)

- BWROG methodology discussed in RIS 2001-15

- BWROG methodology iterates over entire stroke length to determine changes in output capability and actuator speed

- BWROG calculates final stroke time and capability margin 202

Torque Switch Available Thrust Output TSTTHU =

TSTMEAS 1 - BROL - UROL 2 + UDIA 2 + UTSR 2

where TSTMEAS = measured thrust at torque switch trip BROL = bias uncertainty due to rate of loading UROL = random uncertainty due to rate of loading UDIA = random uncertainty due to diagnostic equipment UTSR = random uncertainty due to torque switch repeatability Also, consider spring pack relaxation and stem lubricant degradation 203

Rate of Loading (Load Sensitive Behavior)

ROL% = ThrustTST Static - ThrustTST Dynamic

100%

ThrustTST Static Use statistical method with 95% confidence to establish random and bias uncertainties 204

Available MOV output least of:

- motor actuator output capability (adjusted for degradation)

- torque switch available output

- operator torque/thrust rating (or justified extension)

- maximum spring pack setting

- valve torque/thrust weak link 205

Motor Actuator Capability (Butterfly valve)

Output Torque =

SMB output

HBC Gear Ratio

HBC Gear Efficiency where HBC Gear Ratio and Efficiency obtained from Limitorque SEL documents.

For high flow velocities, actuator might need to exert a restraining torque to prevent disc from slamming into or through the valve seat (see EPRI Application Guide).

206

5.d Uncertainties 207

Gate and Globe MOV Output Uncertainty Examples

- Test Equipment Inaccuracy

- Control Switch Repeatability

- Rate of Loading (Load Sensitive Behavior)

- Spring Pack Relaxation

- Stem Lubricant Degradation Limit or torque switch control, and use of diagnostics, will determine applicability of uncertainties.

208

Butterfly Valve MOV Output Uncertainty Examples

- Test Equipment Inaccuracy

- Control Switch Repeatability

- Spring Pack Relaxation

- Seat Degradation (e.g., seat hardening)

Limit or torque switch control, and use of diagnostics, will determine applicability of uncertainties.

209

5.e Margins 210

MOV Margin for Gate and Globe Valves Static Test Close Margin = ThrustTST MEAS - Uncertainties - Required Thrust Open Margin = Actuator Available Thrust - Uncertainties -

Required Thrust Dynamic Test Close Margin =

ThrustTST MEAS - Uncertainties - Extrapolated Required Thrust with uncertainties Open Margin =

Act. Avail Thrust - Uncertainties - Extrapolated Required Thrust with uncertainties 211

Example Torque Switch Thrust Window for Gate and Globe Valves Maximum Thrust Allowed (including actuator, valve, stem-disc connection, motor, and spring pack)

Maximum reduced for Diagnostic Uncertainty, Torque Switch Repeatability (TSR), and others as applicable Upper Limit of Thrust Window Lower Limit of Thrust Window Minimum increased for Margin, Stem Factor Degradation, TSR, Diagnostic Uncertainty, Load Sensitive Behavior, and others as applicable Minimum Required Operating Thrust 212

MOV Margin for Butterfly Valve (Limit Control)

Static Test Margin =

Actuator Available Torque - Uncertainties - Required Torque Dynamic Test Margin =

Actuator Available Torque - Uncertainties - Extrapolated Required Torque with uncertainties 213

5.f Weak link analysis 214

MOV Stall Overtorque and Overthrust Output (Gate and Globe)

ACTTOR = MST

SEff

OAR

VMAX n

VRAT ACTTHR = ACTTOR SF where ACTTOR = motor actuator output torque capability ACTTHR = motor actuator output thrust capability MST = motor stall torque (1.1 times rated motor torque)

SEff = actuator stall efficiency VMAX = maximum voltage at motor (elevated voltage)

VRAT = rated motor voltage n = 2 for ac motor and n = 1 for dc motor if VMAX > 100%

Otherwise, n = 0 215

Weak Link Considerations

Actuator structural thrust and torque capability

Valve structural thrust and torque capability

Stem to disc connection structural capability (including T-Head connections and threaded connections)

Motor torque output capability

Spring pack compression limit 216

5.g Example calculations 217

MOV Calculations

Review determination of design-basis functional requirements.

Review methodologies used for thrust/torque calculations:

- Industry valve factor method

- EPRI Application Guide TR-106563 on MOVs

- EPRI MOV PPM for valve thrust/torque requirements

- Limitorque Technical Update 98-01 (S1) for AC MOV output

- ComEd White Paper 125 for MOV output

- BWROG DC MOV methodology for stroke time and output

- EPRI MOV Thrust Uncertainty Method for torque switch setting 218

Review bases for MOV performance assumptions

- Valve factor (VF)

- Stem friction coefficient (SFC)

- Load sensitive behavior or rate of loading (LSB or ROL)

- Margins for stem lubrication degradation and springpack relaxation

- Motor performance

rating

efficiencies (pullout, run, and stall)

application factor

degraded voltage factor

ambient temperature

- Actuator efficiency

- Degraded voltage 219

Review bases for MOV performance assumptions (continued)

- Differential pressure (DP) load extrapolation

- Control switch trip (CST) repeatability

- Thrust/torque limit extrapolation

- Equipment error

- Degradation

- Grouping (GL 89-10 Supplement 6) 220

Evaluate design-basis capability of sampled MOVs

- Request table of safety-related MOVs indicating ID number; description; open/close safety function; calculation method; MOV type and size (ac/dc motor, actuator, and valve);

risk significance; DP; VF; SFC; LSB or ROL; design thrust/torque; CST thrust/torque; and margin (as applicable)

- Review MOV table for assumptions and margin to demonstrate that all MOVs have design-basis capability

- Select 3 to 5 MOVs for detailed review based on risk and margin, plus other items of interest (such as questions on identified parameters)

- Review design calculations for sampled MOVs for operating requirements, actuator output capability, and margin, including consideration of uncertainties

MOVs should have 5% margin after all uncertainties addressed to avoid operability calls for minor items

- Review stall thrust and torque evaluations

- Expand sample as necessary 221

MOV Operating Requirements

- ASME Standard QME-1-2007 qualification program (RG 1.100)

- EPRI MOV PPM calculation

- Plant-specific test data

- Vendor or industry test data where justified 222

AC motor actuator capability (gate and globe)

(Limitorque Technical Update 98-01, S1)

ACTTOR = MT

Eff

AF

OAR

Temp

VMIN n

VRAT ACTTHR = ACTTOR SF where ACTTOR = motor actuator output torque capability ACTTHR = motor actuator output thrust capability MT = motor rated torque VMIN = minimum voltage at motor VRAT = rated motor voltage If voltage drop > 10%, n = 2 (but n = 0 if 10%)

Eff = pullout efficiency AF = application factor OAR = overall actuator ratio Temp = temperature degradation factor (Limitorque TU 93-03) 223

DC motor actuator capability (gate and globe)

- BWROG methodology discussed in RIS 2001-15

- BWROG methodology iterates over entire stroke length to determine changes in output capability and actuator speed

- BWROG calculates final stroke time and capability margin 224

Butterfly valve motor actuator capability Output Torque =

SMB output

HBC Gear Ratio

HBC Gear Efficiency where HBC Gear Ratio and Efficiency obtained from Limitorque SEL documents 225

Available MOV output least of:

- motor actuator output capability (adjusted for degradation)

- control switch available output

- operator torque/thrust rating (or justified extension)

- maximum spring pack setting

- valve torque/thrust weak link 226

MOV output uncertainty examples

- Test Equipment Inaccuracy

- Control Switch Repeatability

- Rate of Loading or Load Sensitive Behavior

- Spring Pack Relaxation

- Stem Lubricant Degradation

- Butterfly Valve Seat Degradation (e.g., seat hardening)

Limit or torque switch control, and use of diagnostics, will determine applicability of uncertainties 227

MOV Margin for Gate and Globe Valves Static Test Close Margin = ThrustTST MEAS - Uncertainties - Required Thrust Open Margin = Actuator Available Thrust - Uncertainties -

Required Thrust Dynamic Test Close Margin =

ThrustTST MEAS - Uncertainties - Extrapolated Required Thrust with uncertainties Open Margin =

Act. Avail Thrust - Uncertainties - Extrapolated Required Thrust with uncertainties 228

MOV Margin for Butterfly Valve (Limit Control)

Static Test Margin =

Actuator Available Torque - Uncertainties - Required Torque Dynamic Test Margin =

Actuator Available Torque - Uncertainties - Extrapolated Required Torque with uncertainties 229

Example Calculation 230

MOV Actuator YouTube Videos 231 SMB-2 Actuator Failure (Kalsi) https://www.youtube.com/watch?v=TVsUTbUlUSQ Limitorque SMB-0 Internals https://www.youtube.com/watch?v=00Uu_rmPLDs Limitorque SMB-000 Tripper Finger Adjustment https://www.youtube.com/watch?v=5J8yuapOPPk Limitorque Limit Switch Operation https://www.youtube.com/watch?v=85oepWJAVbU Limitorque Limit Switch L Bracket Tension https://www.youtube.com/watch?v=WhT2IMNdLCw

Questions?

233

ML19235A126

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