Valve Manufacturer’s Association
Transcript of Valve Manufacturer’s Association
Addressing Challenges in HIPPS Design and Implementation
Valve Manufacturer’s Association
Afton Coleman, CFSP
March 11, 2016
Agenda
• SIS and SIL basics
• HIPPS Purpose
• Increased demand for HIPPS, why?
• The Challenges faced
• Challenges on a product level
• A Solution addressing all challenges/phases
• Questions
Functional Definition of SIS
• “Safety Instrumented System”: A
system composed of sensors, logic
solvers and final elements designed to:
– Automatically take the process to a safe state when specified (dangerous) conditions are violated
– Permit a process to move forward in a safe manner when specified conditions allow (permissive functions); or
– Take action to mitigate consequences of an industrial hazard
• “Safety Instrumented Function”: SIF
– Safety function which is necessary to achieve functional safety
• “Safety Integrity Level”: SIL
– Level of risk-reduction provided by a safety function, or to specify a target level of risk reduction
RRF
(Risk Reduction Factor)
PFDavg
(Probability of Failure on Demand = 1/RRF)
SIL
(Safety Integrity Level)
100000 to 10000 >=10-5 to <10-4 4
10000 to 1000 >=10-4 to <10-3 3
1000 to 100 >=10-3 to <10-2 2
100 to 10 >=10-2 to <10-1 1
High Integrity Pressure Protection System
Purpose: To protect downstream equipment against overpressure by
closing the source
Increased demand for HIPPS, Why?
The increased demand for HIPPS is driven by different factors.
• Environmental issues
• Regulatory Directives – Reduce Flare
• Reduce CAPEX (Down rate piping)
• Reduce OPEX (test of relief valves)
The Challenges faced
Consider random as
well as systematic
integrity
Lack of Standards
Monitor and test with
system in service? (Fast
closing)
What if failures are
detected by diagnostic?
Regulations are a moving target
EPA, API, ASME
Clean Air Act
ISA S84 / IEC 61511 & 61508
Compliance with
current functional
safety legislation for
all elements of the SIF
Handling of multiple
vendors / consultants
Validation of SRS
Defining SRS and
ensure requirements
are followed through
Challenges Engineering a HIPPS -The causes of failure and the answers
Random failures
• Occur due to:
– Inappropriate application
– Bad design
– Fatigue
• Reduced by
– Material quality
– Consistent appropriate design
– Performance monitoring
• Everything breaks eventually
Systematic failures
• Occur due to:
– Designed in
– Engineered in
– Procedural
• Reduced by:
– Better processes
– Regular verification
– Consistent behavior
• People make mistakes
All components of any solution can fail dangerously
The causes of failure and the answers
• Ensure structure and management of all activities
• Identify activities and objectives
• Manage verification steps
Control the effect of people in every activity
Systematic failuresAnswer - The safety lifecycle
Random FailuresAnswer – Safety Integrity Levels
Risk inherent in the process
Tolerable risk region
Other risk
reduction
measures
Risk reduction
by Safety
Instrumented
System
Incre
asin
g r
isk
Residual risk
Measure risk
Quantify instrumented risk reduction target – SIL
Match design to SIL – PFD etc
Monitor performance, adjust design
Control the effect of dangerous failures
Certified SIS Products and Processes
IEC 61508 Certified Products:– required to provide safety as good as or better than a traditional relief system
– IEC 61508 Certified or Proven in Use products
IEC 61511 Certified Processes:– Provide a single, worldwide framework for consistent designs
– All Integration Centers should be fully certified to IEC 61511
Operation
Implementation
Analysis
Challenges on a product level - Final Control
Valve Application Needs
High safety integrity and redundancy required
Closing Speed
< 2-3 seconds for gas
<6-8 seconds for liquids
Tightness reliability
Inertia
Drive train design (Ball to Stem)
Seat Design
Material selection/overlay
Valve Actuators –
pneumatic spring-return
Addressing Final Control Challenges
Fast Acting ESDV applications
Test entire valve shut down
circuit while in service
High Diagnostic Coverage
Volume Booster tested as
part of PST
Solenoid testing without
moving the valve
Diagnose friction build-up
Diagnose valve shaft shear
Installation Considerations
High safety integrity and redundancy required
Number of tappings
Single tapping susceptibleto plugged impulse line
Testing requirements
Need safety availability during test
Challenges on a product level – Pressure Sensors
Addressing Pressure Sensor Challenges
Diagnostic Capabilities
Plugged Impulse line diagnostic
Systematic Capability: SC3
High Integrity Manifold – 3 tappings
Block-Bleed-Block for test
Single Isolation Key for 3
sensors
ATEX Junction Boxes
Software Considerations
Shutdown loop needs to perform on demand
Consistent configuration necessary
Work practice needs
Proof test procedures
Device testing procedure/method
Communication protocols
Installation Considerations
Need to meet requirements for HMI
Brownfield (existing logic solver)
Are there sufficient I/O to accommodate HIPPS?
Challenges on a product level – Logic Solver
Addressing Logic Solver Challenges
Logic Solver Software
Certified with SC3 (SIL3)
Entire safety loop health
monitoring
SIS Diagnostics
Partial Stroke Capability
Comms interface with DCS
HART Pass-through
Modern Installation
Desirable system footprint and
architecture
Simple “HMI”
Status Lamps
Override Keyswitches
Choose between skid or on-site assembly HIPPS
Ensure the products integrate together
Provide appropriate hazardous area housings
Coordinate of documentation to meet applicable standards
Transfer of products to end destination responsibility
Perform Factory Acceptance (FAT) and Site Acceptance Test (SAT)
Provide “cradle to grave” support
Challenges on a product level – Integration
Challenges on a product level—Integration
Logic Solvers can be mounted on the HIPPS
or as part of a skid
Pre-wired, Pre-tested, Validated Solution
A Solution addressing all challenges
• Certified Systematic Capability 3
• The HIPPS Design use Certified
procedures acc. to IEC 61511
• Single Supplier Management
• Verification of SIL
• IEC 61508 and 61511
compliant
• Proof test and Inspection plan
• Calibration and Operation
records
• IOM for HIPPS
• Compliance report to ensure
Safety Lifetime is addressed
• Validation if required
Questions