API 682, 3rd Edition

(ISO 21049)

API 682 Development ISO 13709 ISO 21049

2004- API 610, 10th Edition API 682, 3rd Edition2003 - 2002 - API 610, 9th Edition API 682, 2nd Edition2001 -2000 -1999 - 1998 - 1997 - 1996 - API 610, 8th Edition1995 - API 682, 1st Edition1994 - 1993 - 1992 - 1991 - 1990 - API 610, 7th EditionPump SpecificationMech. Seal Specification

Scope API 682 - General API 682 is a guideline for the minimum requirement for Shaft Sealing Systemsfor Centrifugal and Rotary Pumps used in petroleum, naturalgas & chemical industry

API 682 3rd EditionContents ScopeDesign RequirementsFlushing Plans

Scope

GeneralSeal CategoriesSeal TypesSeal ArrangementsDesign and Sealing MethodsSeal OrientationsSeal ConfigurationsObjectives

Scope - General

API682 covers seals for shaft diameters

from 20 mm (0,75 in)

to110 mm (4,3 in)

Scope - Seal Categories

Category 1

For non- API610 Seal Chambers

Temperatures from -40 C (-40 F) to 260 C (500 F)

Absolute Pressures up to 22 bar (315 psi)

Scope - Seal Categories

Category 2

For API 610 Seal Chambers

Temperatures from -40 C (-40 F) to 400 C (750 F)

Absolute Pressures up to 42 bar (615 psi)

Scope - Seal Categories

Category 3

Must meet full specification (incl. documentation)

For API 610 Seal Chambers

Temperatures from -40 C (-40 F) to 400 C (750 F)

Absolute Pressures up to 42 bar (615 psi)

Scope - Seal Categories

Cat. 1

Cat. 2

Cat. 3

Distributed inletflush

If specifed

If specifed

Required

Metal-to-metal(housing to pump)

Required

Required inside and outside bolt circle

Seal sleeve size increments

None

10 mm

10 mm

Throttle bush(Arrangement 1)

Fixed Carbon

Fixed Metal(non sparking)

Floating Carbon

Dual seal circulation device head flow curve

Not applicable

If specified

Required

Proposal data requirements

Minimal

Minimal

Rigorous

Contract data requirements

Minimal

Minimal

Rigorous

Scope - Seal Types Type A

Balancedinside-mountedcartridgepushermultiple springsflexible element rotatingsecondary sealing by elastomeric o-ringsDrawing

Scope - Seal Types Type B

Balancedinside-mountedcartridgenon-pusher (metal bellows)flexible element rotatingsecondary sealing by elastomeric o-ringsDrawing

Scope - Seal Types Type C

Balancedinside-mountedcartridgenon-pusher (metal bellows)flexible element stationarysecondary sealing by flexible graphiteDrawing

Scope - Seal Arrangements

ISO 21049 covers 3 Arrangements:

Arrangement 1: one seal per cartridge assemblyDrawing

Arrangement 2: two seals per cartridge assemblywith a containment seal chamber at pressure lessthan the seal chamber pressure Drawing

Arrangement 3:two seals per cartridge assemblywith externally supplied barrier fluid at a pressure greater than the seal chamber pressure Drawing

Scope Seal Methods

Contacting Wet Seals (CW)Seal Faces not Designed to Create Aerodynamic and Hydrodynamic forces to sustain Seperation Gap.

Non-contacting Seals (wet or dry, NC)Seal Faces Designed to Create Aerodynamic and Hydrodynamic forces to sustain Seperation Gap.

Containment Seals (Contacting or Non-contacting, CS)

Scope - Seal Orientations

API 682 covers 3 orientations for Arrangements 2 & 3:

Face-to-BackDrawing(arr.2 default selection & arr. 3 wet seals)

Back-to-BackDrawing(arr. 3 default for gas seals; option for wet seals)

Face-to-Face(arr.3 optional selection for wet or gas seals)

Scope - Seal Configurations

Scope - Objectives

Inner seals should run for at least 25000 hours

Arrangement 1 seals should not allow more than 1000 ml/m (1000 ppm vol) of emission leakage concentrations

containment seals should run- for at least 25000 hours for absolute pressures less than 1,7 bar (25 psi)- for at least 8 hours at full seal chamber conditions

Design Requirements

General

Seal Chamber and Gland Plates

Cartridge Seal Sleeves

Mating Rings

Flexible Elements

Materials

Design Reqmts All CategoriesGeneral

Hook sleeves are excluded

Stationary seals for surface speeds exceeding 23 m/s (4500 ft/min)

Seal flush rates calculated for max. 5 C (10 F) temperature rise

O-ring sealing surfaces 1,6 m Ra (63 in Ra) for static O-rings

O-ring sealing surfaces 0,8 m Ra (32 in Ra) for dynamic O-rings

Design Reqmts All CategoriesGeneral (contd.)

Bores shall have a minimum 3 mm (0,12 in) radius or- a minimum 1,5 mm (0,06 in) chamfered lead-in for static O-rings- a minimum 2,0 mm (0,08 in) chamfered lead-in for dynamic O-rings

Chamfers shall have a maximum angle of 30

Positive retention of seal components in vacuum services

Design RequirementsSeal Chamber and Gland Plate

Minimum radial clearance between rotating components and stationary surfaces shall be 3 mm (1/8 in), except circulation devices

Gland plates to be provided with holes (not slots)

A shoulder to be provided, minimum 3 mm (1/8 in) thick, against dislodging of stationary elements

Design RequirementsSeal Chamber and Gland Plate (cont.)

Seal chamber face run out up to 0,5 m/mm (0,0005in/in)

Minimum ratio of seal chamber pressure to fluid vapour pressure of 1,3 : 1 or a 20 C (36 F) product temperature margin (not for containment seals)

Gland plate and seal chamber connections to be permanently marked

Seal chambers designed for complete venting before start-up

Design RequirementsSeal Chamber and Gland Plate (cont.)

Diametrical clearance for fixed bushings max. 0,635 mm (0,025 in) for sleeve diameters up to 50 mm (2 in). For larger diameters, 0,127 mm (0,005 in) to be added for each additional 25 mm (1 in) of diameter or fraction thereof

For floating bushings:

Tabelle1

Shaft diameterMinimum sleeve radial thicknessSleeve diameterMaximum clearance at pumping temperature

mm(in)mm(in)mm(in)mm(in)

< 57( 80(>3,2505.1(0,200)81 to 120(3,01 to 4,75)0,28(0,011)

Tabelle2

Tabelle3

Design RequirementsCartridge Seal Sleeves

Shaft-to-sleeve diametrical clearance to be E7/h6

Seal sleeve to extend beyond the outer face of the gland plate

Concentricity of seal sleeve to be 25 m (0,001 in) bore / OD

Shoulder to be provided for positively locating the rotating element

2-piece seal sleeves allowed for Arrangements 2 and 3

Design RequirementsCartridge Seal Sleeves (cont.)

Seal sleeve thickness to be 2,5 mm (0,100 in) minimum

In the area of component drive set screws:

Tabelle1

Shaft diameterMinimum sleeve radial thickness

mm(in)mm(in)

< 57( 80(>3,250)5.1(0,200)

Tabelle2

Tabelle3

Design RequirementsMating Rings

Anti-rotation devices to be designed for minimum distortion of the seal faces No clamped faces

No common mating ring allowed for Arrangement 2 and 3 seals

Design RequirementsFlexible Elements

Multiple coil springs to be provided No static lapped joints for sealing allowed

Design RequirementsMaterials

Category 1

Category 2

Category 3

Mech. Seal Face

Carbon

Carbon

Carbon

Mating Ring

SSSiC(Buka 22)

RBSiC(Buka 20)

RBSiC(Buka 20)

Hard / Hard

SSSiC/ SSSiC

RBSiC/

RB SiC

RBSiC/ RBSiC

Secondary elements

FluoroelastomerPerfluoroelastomer (altern.: TFE, Nitrile ..)

Flexible graphite

Springs

Alloy C-276 or Alloy C-4

(single: SS 316 or 1.4571)

Bellows

Alloy C.276 (Type B)

Alloy 718 (Type C)

Sleeves

SS 316 or 1.4571

Housing

SS 316 or 1.4571

Flushing Plans

Flush plan: 11

Flushing Plans

Flush plan: 13

Flushing Plans

Flush plan: 23

Flushing Plans

Flush plan: 32

Flushing Plans

Flush plan: 53ADrawing

Flushing Plans

Flush plan: 53B

Flushing Plans

Flush plan: 53C

Flushing Plans

Flush plan: 71

Flushing Plans

Flush plan: 72

Flushing Plans

Flush plan: 74

Flushing Plans

Flush plan: 75

Flushing Plans

Flush plan: 76

Mechanical Seal TypeType AArrangement 1API 682 Code: C2A1A1161

Mechanical Seal TypeType A Arrangement 2 or 3 API 682 Code:C2A2A1152 orC2A3A1153

Mechanical Seal Type Type BArrangement 1API 682 Code: C2A1B1161

Mechanical Seal Type Type BArrangement 2 and 3API 682 Code:C2A2B1152 or C2A3B1153

Mechanical Seal TypeType CArrangement 1API 682 Code: C2A1C0262

Mechanical Seal TypeType ESArrangement 1API 682 Code: ESA1A1161

Mechanical Seal Type Type ES Arrangement 1API 682 Code: ESA1C0262Guide Sleeve

Mechanical Seal Type Type A Arrangement 2 & 3Guide Sleeve

Accessories Plan 52MECHANICALSEAL

AccessoriesPlan 53a

Mechanical Seal Codes

First letter:Seal Category (C1, C2 or C3)Second letter:Seal Arrangement (A1, A2 or A3)Third letter:Seal Type (A, B, C)Fourth letter(s):Flush Arrangement

Example C2A1A1161:C1= Category 2 (to ISO 13709)A1= Arrangement 1 (single seal)A = Type A (pusher seal)1161= Plans 11 and 61

Any Questions ?

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