Boiler Safety Valves: Practical Guidelines for Maintenance Planning

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Boiler Safety Valves Practical Guidelines for
Maintenance Planning
August, 2008 Harrisburg, PA

• Jim Domitrovich
• Territory Manager
• Consolidated Pressure Relief Valves

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Evolution of Boiler Technology

• On-going boiler enhancements have enabled safe
  and efficient use of boilers in power generation
• Development of the safety valve promoted boiler
  evolution
• Valve advancements increased control to reduce
  risk
• Most important safety device on a boiler or
  pressure vessel
• Last line of defense in overpressure situations
• Protects employees, equipment and environment

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The Role of Dresser Consolidated

• 130 year history with pressure relief solutions
  for the power generation industry
• Expertise and application knowledge
• Commitment to safe, efficient boiler operation
• Address unique challenges from any application
• Support from initial design phase through
  long-term
• maintenance programs utilizing our GTC Network

• Elevating valve performance by elevating the
  level of customer care

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Safety Valve Maintenance

• Critical to safe and efficient boiler operation
• Decreases cost of ownership
• Development of a safety valve maintenance program
  can be a challenge
• Varied operating conditions
• Physical location of valve within plant/boiler
• Determination of operating gap
• Materials used for stack piping, drip pans,
  condensate drains, etc.

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Safety Valve Maintenance
How often should I inspect or repair my safety
valves? Repair intervals for boiler safety
valves should be . . . determined by
operating experience. The National Board
Inspection Code Section RB-8410 At the
user level, this statement can be hard to define
without knowledge of numerous operating factors.
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An innovative solution from an industry expert

• Safety valve maintenance tool
• Interactive CD
• Created for boiler applications
• Template for developing in-house maintenance
  programs
• Evidence-based approach
• Defines factors that must be considered
• Based on real-life condition
• Predicts an estimated repair / maintenance
  interval

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Estimated Repair Interval

• Contributing factors for safety valve condition
  identified
• Each factor assigned a weight
• Based on operational knowledge and actual repair
  experience
• Select factor from drop down list
• Example Operating Gap
• Continue to populate factors

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Competitive Comparisons

• Total combined factor weight populates
  automatically
• For this application, factor weight is 48
• Click on Estimate Repair Interval

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Estimated Repair Interval

• For this valve, the estimated repair interval is
  approx. 14 months
• Reasonable estimate for repair intervals of
  boiler safety valves Based on real life
  factors that define the National Boards
  reference to determined by operating
  experience

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Safety Valve Failure

• A number of factors can contribute to safety
  valve failure
• Not opening at set point
• Not achieving full lift
• Not closing after reaching blow-down value
  (Hang-Up)
• Valve leakage
• Not opening at all (Worst scenario)

Planning a maintenance program using the CD
tool can help avoid these failure factors
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Conclusion

• Benefits of planning for inspection, maintenance
• and repair
• Identification of operational trends
• Improves access to critical valve data (Valvkeep)
• Assists in trouble-shooting
• Manages repair process workflow
• Provides details for compliance reports
• Helps prevent costly valve failures

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Conclusion

• Any questions?

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