Post on 05-Jan-2016
Boiler Safety Valves: Practical Guidelines for Maintenance Planning
Jim DomitrovichTerritory Manager
Consolidated® Pressure Relief Valves
August, 2008 • Harrisburg, PA
2
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
3
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
4
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.
5
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.
6
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
7
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
8
Competitive Comparisons
•Total combined factor weight populates automatically
•For this application, factor weight is 48
•Click on “Estimate Repair Interval”
9
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 Board’s reference
to “determined by operating experience”
10
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
11
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
12
Conclusion
Any questions?