FSRUG Feedwater Systems Reliability Users Group (Jan 2014) San Antonio, TX Stuffing Box Design & Configurations Presenter: Art Washburn, P.E.

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FSRUG DISCUSSION POINTS Two Rules to Get You Home and Plant Priorities Case 1: API Plan 11 – Packing Injection Flush… Exhibits Excessive Leakage During Operation and Standby (Horizontal Multi-Stage Pump in Auxiliary Service Water Service) Case 2: API Plan 13 – Reverse Flush System… Exhibits No Reverse Flush (Static System), Excessive Packing Leakage, Excessive Packing Sleeve Wear and Severe Stuffing Box Bearing Damage (Vertical Pump in Screen Wash Service) Case 3: API Plan 13 – Reverse Flush System… Exhibits Excessive Packing Leakage (Vertical Pump in Condensate Service) Case 4: API Plan 13 – Reverse Flush System with Bypass Port (Water Service and Hydrocarbon Service) Source References

FSRUG Two Rules:

FSRUG Two Rules: Rule #1 – Make Conservative Decisions

FSRUG Two Rules: Rule #1 – Make Conservative Decisions Rule #2 – Maintain Design Control

FSRUG Two Rules: Rule #1 – Make Conservative Decisions Rule #2 – Maintain Design Control Plant Priorities:

FSRUG Two Rules: Rule #1 – Make Conservative Decisions Rule #2 – Maintain Design Control Plant Priorities: 1.Nuclear Safety

FSRUG Two Rules: Rule #1 – Make Conservative Decisions Rule #2 – Maintain Design Control Plant Priorities: 1.Nuclear Safety 2.Legal Requirements

FSRUG Two Rules: Rule #1 – Make Conservative Decisions Rule #2 – Maintain Design Control Plant Priorities: 1.Nuclear Safety 2.Legal Requirements 3.Efficiency

Case 1: API Plan 11 – Packing Injection Flush (Original) FSRUG Conditions: Excessive Packing Leakage - In Service - In Standby

Case 1: Horizontal Multi-Stage Pump Sectional Aux Service Water Pump FSRUG Stg 1, 260 psi Psuction, 30 psi

Case 1: In-Board Bearing Housing Assembly FSRUG Conditions: Packing Leakage Sprays Directly on Bearing Housing Water Intrusion in Bearing Housing Displaces Approx. 50% of Oil

Case 1: Stuffing Box Configuration (Original) FSRUG Conditions: Lantern Ring Mis-Aligned Inner Packing Rings - What Can You Do For Me Today?

Case 1: API Plan 11 – Injection Flush System (Original) FSRUG Stg 1 – 260 psi Psuction, 30 psi Pstuff box, 260 psi Pstuff box, 260 psi Measured Stuffing Box Pressure

Case 1: Stuffing Box Configuration (Updated) FSRUG

Case 1: API Plan 11 – Injection Flush System FSRUG Stg 1 – 260 psi Psuction, 30 psi Pstuff box, 35 psi Pstuff box, 35 psi

Case 1: Stuffing Box Configuration (Updated) FSRUG

Case 1: Stuffing Box Configuration (Updated) FSRUG Results: 1.Packing Sleeve Diameter, Inches 2.Required Flush for Packing or Mechanical Seal in Water Service and Fluid Temperature Less Than 150 o F (1 GPM per 1 Inch of Shaft Diameter): 5 GPM 3.Stuffing Box Pressure: Maintains Positive Pressure, Easier to Adjust Packing, Reduced Frequency of Packing Adjustments, Eliminate Risk of Packing Spray Impingement on Bearing Housing

Case 1: Stuffing Box Configuration (Updated) FSRUG Analysis Process: 1.Simplify Equation of State to 2 Pressure Drop Devices or Less 2.Iterate Pressure Drop Determination for Both Devices to Share the Total Pressure Until a Mass Balance is Achieved (in GPM) 3. Result: Highly Predictable System Behavior

Water Intrusion – Traditional Oil Deflector vs. INPRO Deflector See EPRI NMAC Lube Notes, November 2004, Bearing Operation with an Oil-Water Mixture FSRUG

Case 2: API Plan 13 – Reverse Flush System (Original) Conditions: Screen Wash Pump Pdischarge, 85 PSI Lantern Ring, Grease Filled Packing exposed to pump discharge pressure Bearing, High Pressure Breakdown Device (Static, melts)

FSRUG Case 2: API Plan 13 – Reverse Flush System (Original) Conditions: Excessive Packing Wear

FSRUG Case 2: API Plan 13 – Reverse Flush System (Updated) Conditions: Screen Wash Pump Pdischarge, 85 PSI Replaced Bottom Packing with Spacer (Controlled Clearance) Lantern Ring, Leak Off Thru Tubing (Orifice) to Sump Bearing dP, 82 PSI Tubing dP, 3 PSI Packing, 3 PSI

FSRUG Case 2: API Plan 13 – Reverse Flush System (Updated) Analysis Seeks Mass Balance Thru the Bushing and Orifice: Bushing: Orifice:

FSRUG Case 3: API Plan 13 – Reverse Flush System (Original) Conditions: Condensate Pump Excessive Packing Leakage Pdischarge, 515 PSI Pabove bushing, 170 PSI

FSRUG Case 3: API Plan 13 – Reverse Flush System (Original) Conditions: Condensate Pump Bottom Lantern Ring Significantly Blocking Plan 13 Return to Suction Lantern Ring Annulus Area too Small – Region Under Packing Does Not Depressurize Packing Sleeve Wear Excessive

FSRUG Case 3: API Plan 13 – Reverse Flush System (Updated) Conditions: Condensate Pump Bottom Lantern Ring Resized to Assure Plan 13 Return is Not Blocked Lantern Ring Annulus Area Increased to Allow Depressurizing Region 360 Degrees Around Shaft

FSRUG Case 3: API Plan 13 – Reverse Flush System (Updated) Conditions: Condensate Pump Interstage Pressure Acting on Packing Rings is Low, Gland Water Injection Maintains Positive Pressure on Packing to Prevent Air In-Leakage Packing Leak-Off Easily Controlled and Sleeve Wear Low Condensate Pump Interstage Pressure Acting on Packing Rings is Low, Gland Water Injection Maintains Positive Pressure on Packing to Prevent Air In-Leakage Packing Leak-Off Easily Controlled and Sleeve Wear Low

FSRUG Case 4: API Plan 13 – Reverse Flush System with Bypass Port(s)

FSRUG Case 4: API Plan 13 – Reverse Flush System with Bypass Port(s) Conditions: Bypass Port(s) may Not be Required for Water Service Bypass Port(s) are Required for Hydrocarbon Service (Low Specific Gravity Product)

FSRUG Case 4: API Plan 13 – Reverse Flush System with Bypass Port(s) Conditions: Bypass Port(s) may Not be Required for Water Service Bypass Port(s) are Required for Hydrocarbon Service (Low Specific Gravity Product)

SOURCE REFERENCES: Centrifugal Pumps: Design & Application, Lobanoff and Ross (practical application) Centrifugal and Axial Flow Pumps, Stepanoff (theory) Centrifugal Pumps, Gülich Vertical Turbine, Mixed Flow & Propeller Pumps, Dicmus Centrifugal Pump Handbook, Sulzer Pump Handbook, Karassik Centrifugal Pump Clinic, Karassik Centrifugal Pumps Selection & Operation, Karassik Centrifugal Pumps, Karassik In-Tandem 3.0 for Windows, EG&G Sealol (John Crane) ABZ Inc, Design Flow Solutions Software FSRUG

WHO IS THIS SYSTEM ENGINEER?

FSRUG TAYLOR SMITH – Comanche Peak

THE (HAPPY) END QUESTIONS ? FSRUG