Safety and Environmental Vapor Control Equipment

Manufacturing and Engineering

Solutions

Agenda

What are the Differences Between Flame Arrestor Products?

What are Tank Vents and What Influences Their Use?

What is Tank Blanketing?

Safety & Environmental Vapor Control Equipment

Three Basic Arrestor Types

End-of Line Arrestor At the End of a Pipe Inline Deflagration Arrestor Limits on Run-Up Distance, Obstructions and Bends Detonation Arrestor Stable DFA has Installation Limits NOTE: Unstable DFA may be located anywhere

in Piping System

UNCONFINED DEFLAGRATION

Confined Deflagration/Detonation

Flame Velocity Profile

Pressure Front Profile

Unconfined/Low to Medium Pressure

Element Designed for Low to Medium Pressure Deflagration Flame Front

High Pressure Deflagration/Detonation

Multiple Element With Patented Diverter Screens For Better Heat Transfer Characteristics,

To Extinguish High Velocity Flame Fronts, Including Detonation. Also Absorbs Momentum Energy.

Industry Standards

EN 12874 ATEX United States Coast Guard USCG

Factory Mutual FM

ISO-EN 16852

API 2000 Compliance

Flame Arrestor Selection Basics

First, Determine The Location Of All Potential Ignition Sources Second, Evaluate The System To Determine Exactly What Should Be

Protected Third, Place The Arrestor Device Between Potential Ignition Source And

The Item To Be Protected.

Flame Arrestor Options

Temperature Measurement

Temperature Switches

Differential Pressure Drain Ports

Relief Valve Products (Breather Vents, PVRVs)

Pressure Vacuum Relief Valves (Breather Vents)

Emergency Pressure Relief Valves

Standards Scope

API 2000 Covers the Normal and Emergency Venting Requirements

for Aboveground Liquid Petroleum Product Storage Tanks and

Underground Refrigerated Storage Tanks

Designed for Operation at Pressures from Vacuum through 15 psig.

API 12F Provides Information for Venting Requirements for Both

Normal Venting and Emergency Venting for Shop Built Welded

Atmospheric Storage Tanks

Key Issues

Tank Venting Products should Protect the tank from over pressure and over vacuum conditions during normal day-to-day operations

Protect the tank from emergency conditions such as ruptured heating

coil or fire

Provide tight sealing at normal operating pressures Meet increasing regulation and environmental concerns

How Could This Happen?

Or This?

Pressure Relief for Pipe-Away PVRV

Tank Vapors

Vacuum Relief for Pipe-Away PVRV

Atmospheric Air

Combination Vent Valve & Flame Arrestor

Provides Flame Protection and Pressure-Vacuum Relief

Dead Weight Emergency Pressure Relief Vent with Spring Loaded Vacuum Port

The Weight of Lid Determines the Pressure Setting Spring Selection Determines Vacuum Setting

Model A Deadweight Hatch / 920 Stack Vent Valve

2 Stack Vent Valve

Model A Deadweight Thief Hatch

ES-660 Hatch / 950 PVRV / 2000 EPRV

Model 950 Pressure / Vacuum Vent

ES-660 Thief Hatch

Series 2000 Emergency Vent

850 Pipe-Away Vent / 2000 Emergency Vent

Series 850 Pipe-Away Vent

Series 2000 Emergency Vent

950 Pressure / Vacuum Valve and 8 API Adapter with ES-660 & 2000 EPRV

Tank Blanketing Products

Type 1190

Type ACE95 Type ACE95jr

Type Y693 Type T205/T205B

Fisher Regulator Products

Tank Blanketing

Tank Blanketing is the process of using an inert gas at very low pressures to keep atmospheric air out of the vapor space in a storage tank.

The main reasons to use Tank Blanketing are: Safety Product Quality Environment Tank Integrity

Key markets/applications: Chemical Petrochemical Oil & Gas Food & Beverage Semiconductor Pharmaceutical

Tank Pressure Control Air & moisture can enter tank Volatile emissions can escape from

tank Tanks are not sealed enclosures Air & moisture can enter the tank

During temperature decreases and pump-out operations To prevent this, a slight positive pressure can be applied

inside the tank (gas blanketing) Pressure Regulators are the normal, accepted device

for this type of service. Volatile emissions can escape from tank

During temperature increases and pump-in operations To prevent this, pressure relief can be used Relief gas can be sent to an environmental device before

discharge to atmosphere

How is the Vapor Space Pressure Controlled in a Gas Blanketed Tank

Through a combination of make-up pressure and pressure relief devices Make-Up

Pressure Reducing Regulator Relief

Conservation Vents (Self and Pilot Operated) Pressure Relief Regulators (Self and Pilot Operated)

Pressure relief Make-up pressure

How Do These Systems Work Together on a Gas Blanketed Tank?

Make-up pressure and pressure relief work together with Emergency Venting through establishing proper setpoints for each

Setpoints for pressure relief are higher than those for make-up pressure to minimize blanketing gas usage Emergency Venting (pressure/vacuum) values are set outside of the normal operating range of operation

Set to protect tank structure in event of a upset condition Setpoints should not overlap for proper operation! The result will be decreased device cycling, less blanketing gas consumption, and less venting

Best Practices in Pressure

Protection and Tank Safety

Solving Backpressure Issues on Rupture Disks

Relief Valve Isolation with

Rupture Disks

Jay Baker BS&B Safety Systems

Sales Manager Engineering Firms

What is a Rupture Disk?

A non-reclosing pressure relief device designed to activate at a specified pressure, thus protecting the vessel and personnel

A designed weak point in a system

The last line of defense in pressure

protection

What is a Safety Head?

A Safety Head is rupture disk holder

A Safety Head is designed for compatibility with its rupture disk

The Safety Head clamps the disk into the piping scheme to ensure proper performance

Not all rupture disks require a safety head

Solving Backpressure Issues on Rupture Disks

Typical Pressure Protection

Tank has a MAWP Rupture disk is set at or

below tank MAWP No backpressure

Venting to atmosphere Venting to catch tank

Tank is protected

Rupture disk

Concerns with Backpressure

Backpressure will increase the burst pressure Rupture disks are pressure differential devices Tank may no longer be protected Code violation may occur Personnel and equipment at risk

Concerns with Backpressure

Disk design may not be suitable Damage to disk could occur Disk could activate in the wrong direction Burst pressure can be affected Other equipment may be damaged

Concerns with Backpressure

BP Thunderhorse 2008 Incorrect rupture disk installed Activated in wrong direction Fragmentation went inside of compressor Entire rig shut down for weeks

Types of Backpressure

Superimposed Backpressure Downstream pressure applied on the disk prior to

activation May come from unintended source Affects the burst pressure and disk design

Constant Variable

Built-Up Backpressure Pressure resulting from the flow of fluids through an open

rupture disk Does not affect burst pressure

Designs for Backpressure

Backpressure Support (Disk) Similar to a vacuum support, but stronger Prevents disk from reversing Formed to match curvature of disk Bar or dial type support

Flat disk designs

Reverse Buckling Circular-Scored or Solid Metal

Withstands 1 to 5 times the marked burst pressure

Must be tested to confirm damage does not occur

Backpressure Support

Designs for Backpressure

Backpressure Support (Holder) Used for very high backpressure

conditions Welded or machined into the holder inlet Bar or dial type support

Flat disk designs Size may need to be increased to offset

reduced flow area Backpressure

Support

Accounting for Backpressure

Derate the rupture disk Reduce burst pressure by the amount of

backpressure Ensure datasheet shows the reduced

burst pressure and explains why Example: A 100 psig tank has 20 psig

constant backpressure. The rupture disk should be specified at 80 psig.

Accounting for Backpressure

Double Disk Assembly Used when the operating pressure

does not allow disk to be derated Upstream disk specified at the

desired burst pressure Downstream disk is derated by

backpressure amount During an overpressure event, both

disks will activate

Accounting for Backpressure

Double Disk Assembly Ensure the space between the disks

contains no pressure Tagging must be clearly defined so

disks do not get switched Datasheet (or datasheets) need to

show two distinct rupture disks Alternatively, two single assembles

separated by a spool may be used

Relief Valve Isolation with Rupture Disks

Questions?

Safety and Environmental Vapor Control Equipment Manufacturing and Engineering SolutionsAgendaThree Basic Arrestor TypesSlide Number 4Slide Number 5Confined Deflagration/DetonationFlame Velocity ProfilePressure Front ProfileUnconfined/Low to Medium PressureHigh Pressure Deflagration/DetonationIndustry StandardsFlame Arrestor Selection BasicsFlame Arrestor OptionsRelief Valve Products (Breather Vents, PVRVs)Standards ScopeKey Issues How Could This Happen?Or This?Pressure Relief for Pipe-Away PVRVVacuum Relief for Pipe-Away PVRVCombination Vent Valve & Flame ArrestorDead Weight Emergency Pressure Relief Vent with Spring Loaded Vacuum PortModel A Deadweight Hatch / 920 Stack Vent ValveES-660 Hatch / 950 PVRV / 2000 EPRV850 Pipe-Away Vent / 2000 Emergency Vent950 Pressure / Vacuum Valve and 8 API Adapter with ES-660 & 2000 EPRVTank Blanketing ProductsTank BlanketingTank Pressure ControlHow is the Vapor Space Pressure Controlled in a Gas Blanketed TankHow Do These Systems Work Together on a Gas Blanketed Tank? Slide Number 32Slide Number 33Best Practices in Pressure Protection and Tank SafetySolving Backpressure Issues on Rupture DisksRelief Valve Isolation with Rupture DisksJay Baker BS&B Safety SystemsSales Manager Engineering FirmsSlide Number 36Slide Number 37Solving Backpressure Issues on Rupture DisksTypical Pressure ProtectionConcerns with BackpressureConcerns with BackpressureConcerns with BackpressureTypes of BackpressureDesigns for Backpressure Designs for Backpressure Accounting for BackpressureAccounting for BackpressureAccounting for BackpressureRelief Valve Isolation with Rupture DisksWhy Isolate a Relief Valve?Is it safe to Isolate?Tell-Tale Assembly Is it Safe to Isolate Downstream? Burst SensorsSlide Number 55Questions?