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