© John Crane Type 28 Gas Seals Range introduction and operating principles
Oct 26, 2014
© John Crane
Type 28 Gas SealsRange introduction and operating principles
© John Crane
Programme Overview
John Crane Introduction
Dry Gas Seal Application Turbo-Machinery
Brief History of Dry Gas Seals
Seal Design & Operating Principles
T28 Product Range
T28 Gas Seal Configuration & Operation
Control & Monitoring Systems
Q & A
© John Crane
John Crane Introduction
© John Crane
Smiths Group plc
John Crane is a Division of Smiths Group plc• 6,400 Employees• £626 million sales 2008
Smiths Group plc is a forward-thinking, focused engineering company with worldwide market-leading positions in its four chosen areas of specialization
• Medical• Detection• John Crane• Flex-Tek & Interconnect
© John Crane
A Global Leader
For over 80 years John Crane has had a passion for innovation
We are the acknowledged world leader and the largest developer, manufacturer and provider of:
Products:• Engineered mechanical seals• Sealing support systems• Power transmission couplings• Engineered bearings
Solutions:• Service• Reliability contracts• Asset management solutions• Oil & water chemistry consultancy
© John Crane
Asia Pacific
Europe Middle East Africa
North America
LatinAmerica
America’s Europe Asia Africa
Organisation
© John Crane
184 facilities in 43 countries
20 manufacturing plants
Over 80 service centres
1350 customer support Ens.
JCMSD DevelopmentJCMSD ManufacturingJCMSD Sales/Service
SloughChicago
Organisation
FranceHamilton
Mexico Venezuela
Washington
Sao Paulo
Italy
GermanyCzech Rep.
TianjinOsaka
Singapore
Madras
SydneyVictoria
Quebec
Sales £500M
© John Crane
John Crane Korea
John Crane KOREA는 1988년에 John Crane이 100% 투자하여한국내에설립되었고, 현재서울 Headquarter , 부산 Factory & Sales Office , 여수 Sales Office 를운영하고있으며 Sales Technical Engineer가전국에서활동중입니다.
John Crane KOREA는 Engineering Expertise , Technical Service, Global Supply Channels , Contracted Seal Reconditioning , Alliance 등의 Capability를갖고있습니다.
© John Crane
Established in 1988
Wholly-owned Smiths subsidiary
Headquarter in Seoul
Factory & Sales office in Pusan
Sales office in Yeochun
Integrated Flexibox Korea in 1999
John Crane Korea
Profile
© John Crane
Head Office in Seoul
© John Crane
John Crane Facility in Busan
© John Crane
Workshop in Busan
© John Crane
Sales Offices
Sales in Busan
Sales in Yosu
© John Crane
Mechanical seals Power transmission couplings Sealing support systems Spares
Running spares Repair Retro-fit
Asset management Seal management Stock management
KNOWLEDGE SERVICE EXPERIENCE
Value Added Solutions
John Crane has developed a world leading E-Business solution providing us and our customers with an opportunity
to achieve mutual benefits
© John Crane
Dry Gas Seal Application Turbo-Machinery
© John Crane
Extraction & ProductionOffshoreOnshore
Gas Gathering &TransmissionGas TreatmentGas StoragePipelineLNGGTL
RefineriesCatalytic ReformerHydrotreaterHydrocrackerFluid Catalytic CrackerGTL
Petrochemical PlantsEthyleneMethanolButyl Polymers
Organic ChemicalsAmmoniaUreaAcetylsNitric Acid
Dry Gas Seal Applications
© John Crane
Type 28XP
Type 28AT
Type 28GP
Compressors Type 28GP/AT
Pumps
Steam Turbines
Turboexpander
Type 28LD Type 28SC
Type 28VL Type 2800 Type 2800E
Type 285 Type 5620USP
Type 28ST
Type 28SST
Mixers Blowers
Non-Contacting Seal Products
Type 28EXP
Gas TurbinesType 28GT
Type 28LDCK728/738Type 5280
© John Crane
Type 28ATType 28AT
Gas Compressor Sealing
© John Crane
Turbomachinery Product
John Crane Dry Running Gas Seal
CompressorsCompressors
© John Crane
Dry Gas Seal Applications
A between bearings compressor normally contains two Type 28 gas seals
© John Crane
Gas Seals in a Compressor
CompressorCompressor
Gas SealGas SealGas SealGas Seal
© John Crane
Typical Compressor
ManMan--Turbo CompressorTurbo Compressor
© John Crane
Typical Compressor
Nuovo Pignone 2BCLNuovo Pignone 2BCL
Diaphragm BundleDiaphragm Bundle
© John Crane
Compressor Train – Nuovo Pignone
© John Crane
Compressor Train - MHI
© John Crane
-- Increased Increased safetysafety
-- 98% 98% power savingspower savings
-- 97% 97% reduction in gas lossesreduction in gas losses
-- Eliminate contaminationEliminate contamination
-- Considerable Considerable reliabilityreliability improvementimprovement
-- SimpleSimple pipe work / support systempipe work / support system
-- No seal oil consumption No seal oil consumption -- $US500k$US500k
Dry Gas Seal Benefits over Oil Seals:Dry Gas Seal Benefits over Oil Seals:
DGS Benefits
© John Crane
Brief History of Dry Gas Seals
© John Crane
Once Upon a Time ...
John Crane founded in 1917 – Chicago, Illinois, USA
Crane Packing Limited established in Slough, England, UK, in 1923, by Frank Payne - the Company President.
Enlarged Berwick Avenue Works Enlarged Berwick Avenue Works Slough 1936Slough 1936
Frank PayneFrank Payne
© John Crane
Type 28 Gas Seal Milestones
1968 First patent 1975 First field applications 1981 First beam type compressor 1985 First steam turbine 1985 First offshore 1986 First H2 recycle compressor 1991 Bi-directional seal 1992 XP seal - 123 to 200 bar 1994 Type 82 separation seal introduced 1995 First H.P. re-injection 1997 Worlds Largest 330mm Gas Seal 1998 400 bar seal test 1998 100,000,000 Operating hours 2000 T28 EXP 350bar Tandem Seal 2002 First fully operation service centre commissioned 2004 Infrastructure investment for 500mm seal + 5 service centres operational 2005 £3m investment in testing and development facilities 2005 Reliability team founded 2005 425 bar EXP seal with independently verified performance 2006 5 new test rigs commissioned 2007 Global service centre network 2008 Next generation separation seals T83/T93FR launched
© John Crane
0
50
100
150
200
250
300
350
400
450
1985 1990 1995 2000 2005
Pres
sure
(Bar
)Gas Seal Performance Progress
AT TripleXP Tandem
XP Triple
XP Quad
EXP Tandem
(Cran
ite &
ADC)
AT Tandem
© John Crane
John Crane invented the dry gas seal 30 years ago. Gas seals have revolutionised turbomachinery sealing
Gas seals are installedin the majority of newcentrifugal compressors Gas seals are fitted as
standard by all majorcompressor OEMs Over 20,000 gas seals supplied Over 200 million operating hrs
Type 28 Gas Seal Experience
© John Crane
Manufacturing Sites - Dry Gas Seals
= Dry Gas Seal Manufacturingand Reconditioning
JC UK, Slough
JC Inc, ChicagoJC Japan, Ritto
© John Crane
Sales and Service Sites
= Regional DGS Repair & Test Centres
JC Brazil
JC NorwayJC Russia
JC Saudi Arabia
JC Tianjin
JC Singapore
© John Crane
Dry Gas Seal Operating Principles
© John Crane
UNIDIRECTIONALSPIRAL GROOVE
BIDIRECTIONAL SPIRAL GROOVE
Spiral Groove Comparison
Operating Principles
© John Crane
Spiral Groove Dry Gas Seals
Features
•Cartridge seal - relatively simple to fit
•No wet seal system
•Gas lubricated – usually by the process gas
•Non-contacting faces
© John Crane
Mating Ring
Primary Ring
ShaftShaft
Type 28 Principles of Operation
Spiral Groove
© John Crane
clockwise shaft rotation
outer diameter
Opposingface innerdiameter
Innergroove
diameter
spiral groove
Sealingdam
Rotating Mating Ring
Spiral Groove Sealing Surface
© John Crane
Direction of Rotation
Spiral Groove Pattern
The Spiral Groove pattern is uni-directional only
Gas is pumped inwards by rotating spiral groovesMating Ring
Gas is compressed & Pressure increases to set gap
© John Crane
Hydrodynamic Lift Optimisation -Spiral Groove
InterfaceInterfacePressurePressure
Face Face ProfileProfile
Face ODFace OD
Face IDFace ID
GrooveGrooveGrooveGroove
DamDam
GrooveGroove
GrooveGroove
RotationRotation
© John Crane
Spiral Groove Geometry
Optimised spiral groovesOptimised spiral groovesMaximum lift pressure generated.Maximum lift pressure generated.
CStedy bespoke design and analysis tool
© John Crane
Hydrodynamic Lift
© John Crane
Grooves for Dry Gas Seals
Spring LoadedCarbon Face
Rotating Seatwith RecessedGrooves of Micrometers Depth
Sealing Interface Film Thickness of SeveralMicrometers
© John Crane
Dry Gas Seal Technology
Bi-directional Rotation Seal
John Crane Type 28ATBD / 28XPBDJohn Crane Type 28ATBD / 28XPBDHigh Performance BD Profile
© John Crane
Bi-Directional Groove Pattern
Type 28BD PatternType 28BD Pattern
© John Crane
Type 28 Principles of OperationBi-Directional Spiral Groove
Direction of Rotation Gas is induced towards thecenter.
Gas is Compressed &Pressure increases toset Gap.
Sealing Dam
© John Crane
Type 28BD Improved Groove
© John Crane
Why Use Grooves?
The Opening Load is the summation of the Hydrostatic force and the Hydrodynamic force. Hydrostatic pressure is generated by an
external source and controlled by the balance ratio of the seal. Hydrodynamic pressure is self-generated where
the pumping and compression action is created by the rotating grooves. Hydrodynamic pressure increases the operating
film thickness and the film stiffness of the sealing gap. Hydrodynamic pressure maintains the non-
contacting sealing interface. Hence zero wear and low frictional heating.
© John Crane
SPIRAL GROOVE
Spiral Groove Comparisons
BI-DIRECTIONALUNI-DIRECTIONAL SPIRAL GROOVESPIRAL GROOVE
© John Crane
Spiral Groove Dry Gas Seals
Some of the Benefits•Non-contacting
•no wear - life of equipment (refurb 3-5 years)• increased reliability - less downtime•reduced maintenance•reduced heat generation - no cooling
•Gas lubricated•no oil system - reduced weight, increased space,
reduced maintenance• low power consumption - typically <5kW• improved operational safety.
© John Crane
The spiral grooves are the heart of the The spiral grooves are the heart of the nonnon--contacting designcontacting design
Precision depth grooves generate liftPrecision depth grooves generate lift No wear or frictional heat generationNo wear or frictional heat generation Grooved component rotates in Type 28Grooved component rotates in Type 28
Spiral Groove Principles
© John Crane
Sealing Interface (Normal Gap)
Closing Force Opening Force
Compression
Expansion
Approx. Gap = 0.003mm
Spring Loadand Hydrostatics
© John Crane
Sealing Interface (Reduced Gap)
Closing ForceIncreased Opening Force
© John Crane
Sealing Interface (Normal Gap)
Closing Force Opening Force
Compression
Expansion
Approx. Gap = 0.003mm
Spring Loadand Hydrostatics
© John Crane
Sealing Interface (Increased Gap)
Closing ForceReducedOpening Force
© John Crane
Sealing Interface (Normal Gap)
Closing Force Opening Force
Compression
Expansion
Approx. Gap = 0.003mm
Spring Loadand Hydrostatics
© John Crane
John Crane – World Leader in Dry Gas Seal Technology
© John Crane
T-28 Dry Gas Seal Design Future
© John Crane
Shrouded drive ring to contain rotating mating ring
Mating ring positively driven on outside diameter
Distortion free Retainer with profile milled drive lugs..
Type 28AT Design Features
© John Crane
Elastomer o-rings Controlled contact
Large diameter multiple springs prevent buckling
Tolerance strip to centralise mating ring on support sleeve accommodating thermal, pressure and centrifugal effects.
Type 28AT Design Features
© John Crane
Secondary Secondary VentVent
Primary VentPrimary Vent Filtered Process Filtered Process GasGas
Type 28AT Tandem Seal
Tolerance StripsTolerance Strips
BearingsBearings Process GasProcess Gas
© John Crane
Centring Devices
Canted CoilCanted CoilStandard Standard Tolerance Tolerance StripStrip
Finger SpringFinger Spring
© John Crane
Compliant balanced stationary carbon primary ring design providing maximum flexibility
Logarithmic spiral or bi-directional
grooves
Tungsten carbide or silicon carbide rotating mating ring
Type 28AT Design Features
© John Crane
Type 28AT Seal Design Features
Compliant Compliant balanced balanced stationary carbon stationary carbon primary ring design providing maximum primary ring design providing maximum flexibilityflexibility
Logarithmic spiral or Logarithmic spiral or bibi--directional directional
groovesgrooves
Tungsten carbide or silicone carbide Tungsten carbide or silicone carbide rotating mating ringrotating mating ring
© John Crane
T-28 Dry Gas Seal Product Range
© John Crane
A between bearings compressor typically comprises two type 28 Dry Gas Seal cartridges.
DGS Applications
© John Crane
DGS Application Range
John Crane DGSOperating Range
Temp: -140 to +315°CPressure: to 425 BargSpeed: to 200m/sShaft: to 330mm
© John Crane
Type 28 AT for duties up to 82 bar*
Carbon seal faces
Elastomeric ‘O’ RingSecondary seal
Explosive decompression at High Pressure!
Chemical Attack! *some specific designs to 120 bar
© John Crane
Seal Configuration & OperationGas Seals
© John Crane
Type 28AT Single Seal
Often external labyrinth
•mainly to prevent ingress of bearing oil
•process gas is non-toxic
© John Crane
Type 28AT Single Seal
Single seal configuration is used mainly with nonSingle seal configuration is used mainly with non--hazardoushazardousgases such as air, nitrogen and carbon dioxide.gases such as air, nitrogen and carbon dioxide.
Process GasProcess GasBearingsBearings
Maximum Maximum DynamicDynamicPressure:Pressure:82 bar g82 bar g
© John Crane
Type 28AT Single Seal Cartridge
Filtered Process Gas
Simplest arrangement for lower cost sealing of non-hazardous process gases
© John Crane
Type 28AT Tandem Seal
Flammable gases
Hazardous gases
Low toxicity gases
90 - 95% applications use tandem seals
© John Crane
Secondary VentSecondary Vent Primary VentPrimary Vent Filtered Process GasFiltered Process Gas
Type 28AT Tandem + Labyrinth
BearingsBearings
NN22 PurgePurge
© John Crane
Type 28AT Tandem Seal Cartridge
N2 Purge Secondary Vent Primary Vent Filtered Process Gas
Bearing Process Gas
For sealing of non-hazardous process gases, with second seal for controlled shutdown in the event of seal failure
© John Crane
Tandem seal with intermediate Labyrinth configuration isTandem seal with intermediate Labyrinth configuration isused with toxic, flammable and hazardous gases.used with toxic, flammable and hazardous gases.
Tandem with Labyrinth
Secondary VentSecondary Vent Primary VentPrimary Vent Filtered Process GasFiltered Process GasNN22 BufferBuffer
© John Crane
Labyrinth
© John Crane
Tandem Type 28AT with Intermediate Labyrinth
N2 Purge Secondary Vent
N2 Purge
Primary Vent Filtered Process Gas
For sealing of hazardous process gases, with controlled leakage to flare, atmospheric emissions limited to process gas combustion products
© John Crane
Inboard seal failure will cause process gas leakage to atmospherInboard seal failure will cause process gas leakage to atmospheree
Tandem with Labyrinth
Secondary VentSecondary Vent Primary VentPrimary Vent Filtered Process GasFiltered Process GasNN22 BufferBuffer
© John Crane
With external Type 82 or double purged labyrinthWith external Type 82 or double purged labyrinthNo process gas leakage to atmosphereNo process gas leakage to atmosphere
Tandem with Labyrinth + Type 82
Secondary Secondary VentVent Primary VentPrimary Vent Filtered Process GasFiltered Process GasNN22 Buffer (1)Buffer (1)NN22 Buffer (2)Buffer (2)
© John Crane
Type 28AT - Double Seal
Used for highly toxic or abrasive process gases and Used for highly toxic or abrasive process gases and compressors with very low suction pressurescompressors with very low suction pressures
BearingsBearings Process GasProcess Gas
NN22 Barrier at 2 bar above Barrier at 2 bar above process pressureprocess pressure
© John Crane
Type 28AT Double Cartridge
N2 Purge Vent N2 Buffer
Bearings Process Gas
For sealing of hazardous process gases, with zero emissions to atmosphere
© John Crane
Type 28AT / 82 - Double Seal
Used for highly toxic or abrasive process gases and Used for highly toxic or abrasive process gases and compressors with very low suction pressurescompressors with very low suction pressures
BearingsBearings Process GasProcess Gas
NN22 Barrier at 2 bar above Barrier at 2 bar above process pressureprocess pressureNN22 BufferBuffer VentVent
© John Crane
Type 28AT Tandem + Type 82
Secondary VentSecondary Vent Primary VentPrimary Vent Filtered Process GasFiltered Process Gas
BearingsBearings
NN22 BufferBuffer
© John Crane
Type 82 Barrier Seal
NN22 at 0.4 bar differentialat 0.4 bar differential
© John Crane
Type 82 Bushing Upgrade - the Type 83 Barrier Seal
Improved Product - Type 83 Barrier Seal
Carbon Segments
Garter Spring
Wave Spring
© John Crane
Basic System
© John Crane
Control & Monitoring System of
Dry Gas Seals
© John Crane
Dry Gas Seal Control SystemDesign - Engineering - Manufacturing - Test
- All done in Singapore
Control and Monitoring System
© John Crane
Typical Nuovo Pignone Panel
© John Crane
Control & Monitoring System :
• Filtration of Buffer Gas
• Regulation of Buffer Gas
• Monitoring of Seal Performance
Control and Monitoring System
© John Crane
Key System Functions
Filter
Control
Measure
Measure Control
Measure
Bearing
© John Crane
FILTEREDSEALGAS
N2 PURGEGAS
SECONDARYLEAKAGE
PRIMARYLEAKAGE
SEPARATIONGAS
PRO
CES
S C
AVI
TY
BEA
RIN
G C
AVI
TY
28XP Tandem Seal with Intermediate Labyrinth Gas Seal Flow Diagram
© John Crane
SEALINGGAS
DGS Control SystemTandem Seal with Intermediate Labyrinth
PI PDIT PDIT
I/P
PDCV
FILTER 1
FIL. 2
PDITPDIT
PIT PDIT
PCV
PDCV
FE
FILTER 1
PI PI
SECONDARY
LEAKAGE
SECONDARY
LEAKAGE
PRIMARYLEAKAGE
PRIMARYLEAKAGE
FEFE
SEPARATION
/ PURGE
GASFI FIFILTER 2
COMPR.
DISCH
PURGE GAS
SEPARATION GAS
© John Crane
Gas Seal Support Systems
Primary Seal / Buffer Gas Supply
Primary Seal Gas Leakage
Secondary Seal Buffer Gas Supply
Secondary Seal Leakage
Separation Gas Supply
© John Crane
FILTER MODULE
PROCESSGAS
Process Gas
EXTERNALGAS
DGS Control System - Seal Gas Supply
© John Crane
FI FI
FILTER MODULE
PROCESSGAS
EXTERNALGAS
Process Gas
Filtered Process Gas
DGS Control System - Filtration
© John Crane
FI FI
FIFLARE
FILTER MODULE
PI PI
FO
PROCESSGAS
EXTERNALGAS
FO
FI
Process Gas
Filtered Process Gas
Process Gas to Flare
DGS Control System - Primary Vent
© John Crane
DGS Control System – Buffer Gas (Nitrogen) Injection
FI FIFI
FIFLARE
N2 SECONDARYFILTER MODULE
FILTER MODULE
PI PI
PCV
FO
PROCESSGAS
EXTERNALGAS
FO
FI
Process Gas
Filtered Process Gas
Process Gas to Flare
Filtered N2 Buffer Gas
FI
© John Crane
FIFI FIFI
FIFLARE
N2 SECONDARYFILTER MODULE
FILTER MODULE
PI PI
PCV
FO
PROCESSGAS
EXTERNALGAS
FO
FO FO
FI
Process Gas
Filtered Process Gas
Process Gas to Flare
Filtered N2 Secondary Gas
DGS Control System - Nitrogen Injection
© John Crane
FIFI FIFI
FIVENTFLARE
N2 SECONDARYFILTER MODULE
FILTER MODULE
PI PI
PCV
FO
PROCESSGAS
EXTERNALGAS
FO
FO FO
FI
Process Gas
Filtered Process Gas
Process Gas to Flare
N2 to Atmosphere
Filtered N2 Secondary Gas
DGS Control System - Secondary Vent
© John Crane
Basic System
1. Basic System
Primary Seal / Buffer Gas Supply Primary Seal Gas Leakage Secondary Seal Buffer Gas supply Secondary Seal Leakage Separation / Barrier Gas Supply
© John Crane
Functional Details Primary Seal / Buffer Gas Supply Module
• Pressure / Flow Control• Filter – Particulate or Coalescing Filter
Primary Seal Leakage Monitoring Module• Monitors primary seal leakage and initiates alarm / shutdown
Secondary Seal Buffer Gas Supply Module (option)• Supplies a flow of clean dry nitrogen to the outboard seal
Secondary Seal Leakage Monitoring Module • Monitors secondary seal leakage and initiates alarm / shutdown
Separation Gas Module• Supplies a flow of clean dry nitrogen to the Separation Seal
(barrier seal)• Monitors pressure or flow to the Separation Seal – Initiates Alarm
if it is low
Basic System
System Functions• Provide clean seal gas
(during normal operation)• Monitor Dry Gas Seal
Performance (leakage flow / pressure & separationseal pressure / flow) Seal / Buffer Gas
Supply ModuleSeal Leakage
Monitoring ModuleSecondary Seal
Buffer Gas ModuleSeparation
Gas Module
Basic
© John Crane
Primary Seal / Buffer Gas Supply Module
Seal Gas Filter
Flow Meter
PDCVInlet
To Seal
To Seal
© John Crane
Primary Seal Leakage Monitoring Module
Flow Meter
From Seal
To Flare
Leakage Blockwith Orifice
Pressure Transmitter
© John Crane
Secondary Seal Buffer Gas Supply Module
Buffer Gas Filter
Inlet
Flow Meter
To Seal
© John Crane
Separation Gas Supply Module
Separation Gas Filter
Pressure Regulator
Orifice Union
To Barrier Seal
© John Crane
John Crane Dry Seal Control System INOVIT