agenda john crane mechanical...
Post on 22-Jul-2020
55 Views
Preview:
TRANSCRIPT
Basic seal principles
Categories of mechanical seal
Pusher / bellows
Cartridge / Conventional
Wet Seals / Gas seals
Split / whole
Single / double Cross Reference Chart
Materials - Cross reference Chart
Sealant Systems
Basic principles
Regulating authorities Seal Selection Guides and gifts
John Crane Mechanical Seals AGENDA
Çandar Akışkan Teknolojileri- www.candar.com.tr
Sealing
Fundamentals
Part 1
Çandar Akışkan Teknolojileri- www.candar.com.tr
Shaft
Process
Fluid Leakage
Environment Vessel
Wall
The Basic Sealing Problem: Preventing Leakage
Çandar Akışkan Teknolojileri- www.candar.com.tr
Shaft
Process
Fluid
Leakage
Environment Vessel
Wall
Packing
Çandar Akışkan Teknolojileri- www.candar.com.tr
Shaft
Process
Fluid
Leakage
Environment Vessel
Wall
The Concept of an End Face Mechanical Seal
Çandar Akışkan Teknolojileri- www.candar.com.tr
Shaft Shaft
Movement
Required Features
Small axial clearance
Çandar Akışkan Teknolojileri- www.candar.com.tr
Shaft
Movement
Required Features
Small axial clearance
Self adjusting
Çandar Akışkan Teknolojileri- www.candar.com.tr
Mating
Ring
Primary Ring Secondary Sealing Element
A Flexible Seal
Hydrostatic loading
Secondary sealing elements
Replaceable parts
Çandar Akışkan Teknolojileri- www.candar.com.tr
O-Ring
Shaft
Mating Ring
Primary Ring
Snap Ring
Anti-X Ring
O-Ring
Disk
Springs
Retainer
Set Screw
An Example of a Complete Seal
Çandar Akışkan Teknolojileri- www.candar.com.tr
Simply put, a mechanical seal is:
1. A rotating face (primary ring)
2. A stationary seat, (mating ring)
3. A secondary sealing element
4. A mechanical loading device to press face
and seat together, and
5. Auxiliary components
Çandar Akışkan Teknolojileri- www.candar.com.tr
Process Fluid Acts as Lubricant Between Faces
Gland Pump Housing
Process Fluid
Invisible Leakage:
Fluid Evaporates Upon Reaching Atmosphere
Primary Ring Mating Ring
Çandar Akışkan Teknolojileri- www.candar.com.tr
Gland
Pump Housing
No Fluid Or Dry Running
Primary Ring Mating Ring
Without Lubrication, Faces Run Dry And Overheat
Çandar Akışkan Teknolojileri- www.candar.com.tr
Heat Transfer
Conduction
Convection
Çandar Akışkan Teknolojileri- www.candar.com.tr
Injection
Flushing
Removes Heat
Replenishes Cool Clean Lubricating Liquid
Çandar Akışkan Teknolojileri- www.candar.com.tr
Primary Seal: Flush
Single Seal Flushing By - Pass from Discharge (API Plan 11)
By- pass Line from
Pump Discharge
to Seal Gland
Discharge
Flow
Suction
Çandar Akışkan Teknolojileri- www.candar.com.tr
Design Features
Balance Ratio
Springs
Secondary Sealing Element Type
Çandar Akışkan Teknolojileri- www.candar.com.tr
Balance ratio is used to control the face load.
Closing Force Opening Force
Design Features
Balance Ratio
Çandar Akışkan Teknolojileri- www.candar.com.tr
Balance ratio is the ratio of the closing area
to the opening area.
A c
A o
Balance Ratio = Closing Area
Opening Area
Design Features
Balance Ratio
Çandar Akışkan Teknolojileri- www.candar.com.tr
An Unbalanced Seal
A A c o F c
Design Features
Balance Ratio
Çandar Akışkan Teknolojileri- www.candar.com.tr
A o A c
A Balanced Seal
Design Features
Balance Ratio
Çandar Akışkan Teknolojileri- www.candar.com.tr
Design Features
Springs
Provide The Initial Closing Force
Are Very Important At Low Pressures
Are Not So Important At High Pressures
Çandar Akışkan Teknolojileri- www.candar.com.tr
Design Features
Springs High Speed Seals Use Stationary Springs
(5000 ft/min Typical Break Point)
Çandar Akışkan Teknolojileri- www.candar.com.tr
Design Features
Secondary Sealing Element Static
Dynamic
Çandar Akışkan Teknolojileri- www.candar.com.tr
O-ring must
move axially
Design Features
Secondary Sealing Element Pusher Seal
Çandar Akışkan Teknolojileri- www.candar.com.tr
Static O-ring
Design Features
Secondary Sealing Element Non-Pusher Seal
Çandar Akışkan Teknolojileri- www.candar.com.tr
Teflon Bellows
Elastomeric Bellows
Half Convolution
Welded Metal Bellows
V Rings U Cup Wedge Encapsulated
O Ring
O Ring
Secondary Sealing Elements
Çandar Akışkan Teknolojileri- www.candar.com.tr
Pusher Non-Pusher
O-ring secondary seal
must slide along shaft as
seal face wears
Bellows secondary seal
expands to accommodate
face wear. Bellows tail is
stationary against shaft
vs.
Pusher vs. Non-Pusher
Çandar Akışkan Teknolojileri- www.candar.com.tr
-400°F
-200°F
0
400°F
600°F
200°F
Buna-N EPDM VitonTM
-54°C / -65°F
149°C /
300°F 121°C / 250°F
-240°C
-129°C
-18°C
204°C
316°C
93°C
AflasTM
204°C /
400°F
204°C / 400°F
-45°C / -50°F -29°C / -20°F
TeflonTM
287°C / 550°F
-212°C / -350°F
-29°C / -20°F
KalrezTM
287°C / 550°F
-40°C / -40°F
Secondary Sealing Elements Temperature Range
Çandar Akışkan Teknolojileri- www.candar.com.tr
Arrangements
Single Inside Mounted
Outside Mounted Multiple
Pressurised
Non-Pressurised
Çandar Akışkan Teknolojileri- www.candar.com.tr
Arrangements
Single Inside Mounted
Çandar Akışkan Teknolojileri- www.candar.com.tr
Arrangements
Single Outside Mounted
Çandar Akışkan Teknolojileri- www.candar.com.tr
Rotating Head and Rotating Seat
Use Rotating Head Assemblies up to: 3500 fpm for Single Spring Designs
5000 fpm for Multiple Spring Designs
Seal Head Seat { Rotating
Rotating Head
Seal Head Seat
Rotating {
Rotating Seat
Stationary
{ {
Stationary
Advantages Less Radial & Axial Space Requirements
Lower Cost
Advantages Higher Speed Capability
Tolerates Misalignment Better
Better Cooling
Arrangements
Çandar Akışkan Teknolojileri- www.candar.com.tr
Classical “Tandem”
Process seal Backup seal
Process seal Barrier fluid seal
Classical “Double”
Multiple Seal Arrangements
Çandar Akışkan Teknolojileri- www.candar.com.tr
Process
Buffer Atmosphere
Pre
ssu
re
Unpressurised
(Tandem)
Multiple Seal Arrangements
Çandar Akışkan Teknolojileri- www.candar.com.tr
Process Barrier
Atmosphere
Pre
ssu
re
PRESSURISE
D (double)
Multiple Seal Arrangements
Çandar Akışkan Teknolojileri- www.candar.com.tr
Types of Seal Failures
Installation
Operation or design of machinery
Seal specification
Çandar Akışkan Teknolojileri- www.candar.com.tr
Failures of Seal Components
Seal Faces
Loss of Flexibility (hang up)
Secondary Sealing Elements
Material Compatibility
Çandar Akışkan Teknolojileri- www.candar.com.tr
Leakage decomposes
or solidifies and locks
primary ring in place
Loss of Flexibility: Hang-up
Çandar Akışkan Teknolojileri- www.candar.com.tr
Categories of mechanical seal
Pusher / bellows
Cartridge / Conventional
Wet Seals / Gas seals
Split / whole
Single / double
John Crane Mechanical Seals AGENDA
Çandar Akışkan Teknolojileri- www.candar.com.tr
Pusher Non-Pusher
O-ring secondary seal
must slide along the
retainer/carbon as the
seal face wears.
Bellows secondary seal
expands to accommodate
face wear.
vs.
SEAL CATEGORIES
Çandar Akışkan Teknolojileri- www.candar.com.tr
SEAL CATEGORIES
O ring seals
Wedge seals
More material options
Higher Pressures
Easier to manufacture
Metal Bellows
Rubber Bellows
PTFE Bellows
No ‘hang up’
Better leakage rates
Better abrasive handling
More tolerant to
misalignments
PUSHER SEALS
(NON BELLOWS)
NON PUSHER SEALS
(BELLOWS)
Çandar Akışkan Teknolojileri- www.candar.com.tr
O-ring
Metal Bellows
Rubber Bellows
Seal Selection by Type
Çandar Akışkan Teknolojileri- www.candar.com.tr
Cartridge Seals / Component Seals
O-Ring Metal
Bellows
Elastomer
Bellows
SEAL CATEGORIES
Çandar Akışkan Teknolojileri- www.candar.com.tr
Single O-Ring Type 5610
Çandar Akışkan Teknolojileri- www.candar.com.tr
SEAL CATEGORIES
Easier to fit - reliable
Factory set - reliable
Less expensive
Adaptable
CONVENTIONAL
(COMPONENT)
CARTRIDGE SEALS
Çandar Akışkan Teknolojileri- www.candar.com.tr
nitrogen injection 2 bar g / 30 psig above maximum seal chamber pressure
Shaft Rotation
ATMOSPHERE OUTBOARD
PROCESS SIDE
INBOARD
Clockwise Counter-Clockwise
Shaft Rotation
Type 2800
Çandar Akışkan Teknolojileri- www.candar.com.tr
Inject nitrogen at 2 bar g / 30 psig above maximum seal chamber pressure
Clockwise Anti-Clockwise
ATMOSPHERE OUTBOARD
PROCESS SIDE
INBOARD
Type 2800E
Çandar Akışkan Teknolojileri- www.candar.com.tr
SEAL CATEGORIES
Less expensive
More complicated support
systems
Can run at low speeds
V low power consumption
V long life
Can run at high speeds
Dry running
WET SEALS GAS SEALS
Çandar Akışkan Teknolojileri- www.candar.com.tr
SEAL CATEGORIES
Can be replaced in stu Less expensive
More reliable
Easier to fit
Higher performance
WHOLE SEALS SPLIT SEALS
Çandar Akışkan Teknolojileri- www.candar.com.tr
SEAL CATEGORIES
Less expensive
No support system Control over fluid film
Emissions containment
SINGLE SEALS DOUBLE SEALS
Çandar Akışkan Teknolojileri- www.candar.com.tr
SEAL TYPE CROSS REFERENCE
U.S. TYPE
1 Rubber Bellows
1B HP Rubber Bellows
NA Rubber Bellows
8-1 O ring
8B1 H.P. O ring
9 PTFE WEDGE
9B H.P. WEDGE
20R PTFE BELLOWS
2800 GAS SEAL
T = Thin seal B = Balanced (HP) seal
R = Replaceable face 5600 is a global cartridge seal range
Types 1B; 2; 8-1; 8B1 do not use the same components in US and UK
Çandar Akışkan Teknolojileri- www.candar.com.tr
SEAL TYPE CROSS REFERENCE
U.S. U.K. EUR TYPE
1 1A NA Rubber Bellows
1B 1B NA HP Rubber Bellows
NA 502 502 Rubber Bellows
8-1 8-1 58U O ring
8B1 8B1 58B H.P. O ring
9 109 59U PTFE WEDGE
9B 109B 59B H.P. WEDGE
20R 10R 10R PTFE BELLOWS
2800 2800E 2800E GAS SEAL
T = Thin seal B = Balanced (HP) seal
R = Replaceable face 5600 is a global cartridge seal range
Types 1B; 2; 8-1; 8B1 do not use the same components in US and UK
Çandar Akışkan Teknolojileri- www.candar.com.tr
US/UK MATERIAL DESCRIPTION CODES
MATERIAL US
Viton X
Carbon F(28) F(3) F(50) F(51)F(55)
Ceramic O(10)
Silicon Carbide O(58)
Tungsten Carbide O(15)
Isolast X(14)
316 Stainless 1
Hastelloy H
Graphoil O(39)
NOTE The above are used only to describe the seal spec. The grades of material are only specified in the code.
Çandar Akışkan Teknolojileri- www.candar.com.tr
US/UK MATERIAL DESCRIPTION CODES
MATERIAL US DIN UK
Viton X V A
Carbon F(28) F(3) F(50) F(51)F(55) B R
Ceramic O(10) V C
Silicon Carbide O(58) Q1 S
Tungsten Carbide O(15) U1 K
Isolast X(14) K X
316 Stainless 1 G 1
Hastelloy H M2 H
Graphoil O(39) G2 X
NOTE The above are used only to describe the seal spec. The grades of material are only specified in the code.
Çandar Akışkan Teknolojileri- www.candar.com.tr
BASIC FUNCTIONS OF A SEALANT SYSTEM
To provide a fluid film when the pump can not, because
the liquid is:
Too hot
Too cold
Too viscous
Prone to solidify or crystallise
Abrasive
Close to boiling point
Contains dissolved gases
The liquid can not get to the seals
Dangerous liquid
Sensitive liquid
Çandar Akışkan Teknolojileri- www.candar.com.tr
BASIC FUNCTIONS OF A SEALANT SYSTEM
From an external source
Higher in pressure than the product at the seal
Contained, usually with another mechanical seal
The sealant as a fluid film must be:
Çandar Akışkan Teknolojileri- www.candar.com.tr
BASIC FUNCTIONS OF A SEALANT SYSTEM
A sealant system must be able to:
Store the sealant
Circulate the sealant
Pressurise the sealant
Cool or heat the sealant
Monitor the sealant
Çandar Akışkan Teknolojileri- www.candar.com.tr
BASIC FUNCTIONS OF A SEALANT SYSTEM
There are 2 type of sealant:
Tanks
Vessels
Çandar Akışkan Teknolojileri- www.candar.com.tr
REGULATING AUTHORITIES
AUTHORITY INSPECTOR
DESIGN ASME VIII
APPLICATIONS API 610
API 682
HAZARDS EUROPE - CENELEC UK - BASEEFA
USA - NEC USA - UL
Çandar Akışkan Teknolojileri- www.candar.com.tr
Process
Barrier
Atmosphere
Pre
ssu
re
Pressurized (Double)
Dual Seal Arrangement
Çandar Akışkan Teknolojileri- www.candar.com.tr
Basic seal principles
Categories of mechanical seal
Pusher / bellows
Cartridge / Conventional
Wet Seals / Gas seals
Split / whole
Single / double Cross Reference Chart
Materials - Cross reference Chart
Sealant Systems
Basic principles
Regulating authorities Seal Selection Guides and gifts
John Crane Mechanical Seals AGENDA
Çandar Akışkan Teknolojileri- www.candar.com.tr
top related