Trainer : MS Jo/Engineering Director Nov 2011 Module 1 Revision 1.2
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Topics • • • • • • • • • • Module 1 Revision 1.2
Review of API 682 First Edition Mission Statement API 682 Second Edition ISO 21049 and API 682 Third Edition Scope of Standard Key Concepts Seal Types Seal Arrangements Categories API Pipe Plan 2
Review of API 682 First Edition • Created by industry leaders in rotating equipment • Designed to capture field experience • Defaults to proven solutions • Applies to the most common applications
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Mission Statement from API 682 First Edition
“This standard is designed to default to the equipment types most commonly supplied that have a high probability of meeting the objective of a least three years of uninterrupted service while complying with emissions regulations.”
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API 682 Second Edition • Success of First Edition • Applications outside of refineries • Application to non-API 610 • Advancement in sealing technology • Creation of an International standard
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ISO 21049 • Review of API 682 Second Edition by worldwide ISO member countries • Reorganization of some chapters • Rewording of some clauses • Error corrections • Modified piping plan selection flowchart • New piping plan Module 1 Revision 1.2
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API 682 Third Edition • Release of ISO 21049 created two standards that were not identical • Third Edition released to make 682 identical to ISO 21049
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Scope of Standard Comparison of Editions
First Edition
Second Edition, ISO 21049, Third Edition
Size
Seal sizes from 1.50” to 4.50” (30mm to 120mm)
Shaft diameters from 0.75” to 4.30” (20mm to 110mm)
Temperature
-40°F to 500°F (-40°C to 260°C)
-40°F to 750°F (-40°C to 400°C)
Pressure (absolute)
0 to 515 PSIA (0 to 34.5 bar)
0 to 615 PSIA (0 to 42 bar)
Fluids
Water, sour water, caustic, amines, some acids, most HCs
Water, sour water, caustic, amines, some acids, most HCs
Pumps
API-610, ISO 13709
ANSI/ASME B73.1 and B73.2, ISO 3069 Frame C, API-610, ISO 13709
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Key Concepts • • • •
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Terminology Seal Types Seal Arrangements Seal Categories
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Seal Types • Over the years, seal companies have released numerous designs and variations • No standardization in seal designs, materials, or dimensions • Challenge for API 682 Task Force was to create standard seal types defining seal design, materials, installation envelope, and operating windows Module 1 Revision 1.2
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Type A Seal
• • • • • •
Rotating flexible element, multiple springs, O-ring secondaries Silicon Carbide versus premium grade blister resistant Carbon Fluoroelastomer O-rings (FKM) Alloy C276 springs (316 for single spring option) Type 316 SS sleeve, gland, and other metal parts Throttle bushing in gland
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Type B Seal
• • • • • •
Rotating bellows, O-ring secondaries Silicon Carbide versus premium grade blister resistant Carbon Fluoroelastomer O-rings (FKM) Alloy C-276 bellows Type 316 SS sleeve, gland, and other metal parts Throttle bushing in gland
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Type C Seal
• • • • • •
Stationary bellows, flexible graphite secondaries Silicon Carbide versus premium grade blister resistant Carbon Alloy 718 bellows Type 316 SS sleeve, gland, and other metal parts Premium carbon floating bushing in gland Bronze anti-coke device
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Rotating vs Stationary • The default Type A and Type B seals have a rotating flexible element • A stationary flexible element is an alternate • The default Type C seal has a stationary flexible element • A rotating flexible element is an alternate • If surface speed at the faces exceeds 4500 ft/min (23 m/s), a stationary flexible element must be used
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Seal Arrangements • The seal arrangement defines the number or seals, their orientation, and details about the seal’s operation • Designations • Contacting wet (CW) • Containment seals (CS) • Non-contacting dry-running • Contacting dry-running
• Non-contacting (NC) • Wet running seals • Dry-running dual seals
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Contacting Wet Seal - CW • “Typical” mechanical seal • Mechanical seal designed to run on liquid fluid film • Does not intentionally create hydrodynamic forces • Requires vapor suppression to keep fluid in a liquid phase • Designed to run for a minimum of 25,000 hours Module 1 Revision 1.2
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Containment Seal - CS • Designed as a dry running backup seal • Outer seal in a dual non-pressurized arrangement • May be either a non-contacting or contacting design • Operates on buffer gas or vaporized process fluid • Run for 25,000 hours at 10 PSI and at least 8 hours under process conditions Module 1 Revision 1.2
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Non-Contacting Seal - NC • May be used as a primary seal or as a dual pressurized seal • Seal is designed to create hydrodynamic forces to separate the faces under all operating conditions • Designed to run for a minimum of 25,000 hours
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Arrangement 1
• • • •
1CW-FX or 1CW-FL configuration Single mechanical seal May have a fixed or floating throttle bushing May have single point or distributed flush
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Arrangement 2 Liquid Buffer Fluid
• 2CW-CW configuration • Dual non-pressurized seal with a liquid buffer fluid • Same as the First Edition Arrangement 2 seal Module 1 Revision 1.2
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Arrangement 2 Vapor or No Buffer Fluid
• 2CW-CS configuration • Contacting wet seal with a dry running containment seal • Containment seal may be either contacting or non-contacting Module 1 Revision 1.2
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Arrangement 2 Vapor or No Buffer Fluid
• 2NC-CS configuration • Inner seal is designed to be non-contacting and operate with liquid, vapor, or mixed phase process • Outer seal a containment seal Module 1 Revision 1.2
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Arrangement 3 Liquid Barrier Fluid
• 3CW-FB configuration • Contacting wet seals oriented in a series (or face-to-back) orientation • Default Arrangement 3 liquid seal • Same as the First Edition Arrangement 3 seal Module 1 Revision 1.2
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Arrangement 3 Liquid Barrier Fluid
• Alternate designs for Arrangement 3 liquid seals • 3CW-BB or 3CW-FF configurations • May be required for specific application or pump designs
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Arrangement 3 Gas Barrier Fluid
• 3NC-BB configuration • Default Arrangement 3 gas seal • Non-contacting gas seals in a back-to-back orientation Module 1 Revision 1.2
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Arrangement 3 Gas Barrier Fluid
• Alternate designs for Arrangement 3 gas seals • 3NC-FF or 3NC-FB configurations • May be required for specific application or pump designs
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Categories • Different applications may require different levels of seal sophistication • Current practice of specifying “modified” API-682 seals • Size restrictions based on pump construction • Cost impact of seals
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Categories Three categories • Category 1 – General duty services in chemical pumps • Category 2 – Heavy duty services; similar to API-610 7th edition seals • Category 3 – Heavy duty services; similar to API 682 First Edition seals
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Comparison of Categories FEATURE
CATEGORY 1
CATEGORY 2
Seal chamber size
ISO 3069 Type C, ANSI/ASME B73
ISO 13709/API 610 ISO 13709/API 610
Temperature range
-40°C to 260°C -40°F to 500°F
-40°C to 400°C -40°F to 750°F
-40°C to 400°C -40°F to 750°F
Pressure range absolute
22 bar 315 PSIA
42 bar 615 PSIA
42 bar 615 PSIA
Face materials
Carbon vs selfsintered SiC
Carbon vs reaction bonded SiC
Carbon vs reaction bonded SiC
Distributed flush requirements
When required or specified
When required or specified
Required
Gland plate metal to metal contact
Required
Required inside and outside bolt circle diameter
Required inside and outside bolt circle diameter
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CATEGORY 3
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Comparison of Categories FEATURE
CATEGORY 1
CATEGORY 2
CATEGORY 3
Seal sleeve size increments
None
10mm increments
10mm increments
Throttle bushing requirements
Fixed carbon, floating carbon optional
Fixed non-sparking metal, floating carbon optional
Floating carbon
Pumping ring HQ curve required
No
If specified
Required
Scope of vendor qualification test
Test as Category 1 unless faces tested as Category 3
Test as Category 1 unless faces tested as Category 3
Test as Category 3 as entire seal assembly
Proposal document Minimal requirements
Minimal
Rigorous including qualification tests
Contract data requirements
Minimal
Rigorous
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Minimal
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Review • API 682 Second Edition represents a major revision over the First Edition • ISO 21049 and API 682 Third Edition provide additional refinement to the standard • The Standard has categorized three types of seals: Type A, B, and C • There are three basic arrangements: Arrangement 1, 2, and 3 • To address differing needs for features and documentation, there are three categories of seals: Category 1, 2, and 3
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Piping Plans • The complete listing of piping plans is covered in Annex • Continuation of piping plans from the First Edition • New piping plans introduced in Second Edition: • Moved over from API 610 • Variations of dual pressurized liquid plans • Plans for containment and dual gas seals
• New piping plans introduced in ISO 21049 / API 682 Third Edition: • Detection of atmospheric side leakage
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Plan 14
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Plan 53A
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Plan 53B
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Plan 53C
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Plan 65
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Plan 71
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Plan 72
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Plan 74
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Plan 75
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Plan 76
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Seal Code • • • •
Informative Different from 1st Edition Different from API 610 Four segment code • • • •
First segment – seal category (C1, C2, C3) Second segment – arrangement (A1, A2, A3) Third segment – seal type (A, B, C) Fourth segment – piping plan (e.g. 11)
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Seal Code • C1A1B11 • • • •
Category 1 seal Arrangement 1 (single seal) Type B seal (bellows) Plan 11
• C3A3A53B • • • •
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Category 3 seal Arrangement 3 (dual pressurized seal) Type A seal (pusher) Plan 53B (liquid barrier fluid pressurized by a bladder accumulator)
Thank you for your Attention. Module 1 Revision 1.2
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