API Standard 682

1 API Standard 682 Pumps Shaft Sealing Systems for Centrifugal and Rotary Pumps FOURTH EDITION | MAY 2014 | 256 PAGES |$ | PRODUCTNO. C68204 This Standard specifies requirements and gives recommendations for sealing systems for centrifugal and rotary pumps used in the petroleum, natural gas, and chemical industries. See and It is the responsibility of the purchaser or seal vendor to ensure that the selected seal and auxiliaries are suitable for the intended service condition. It is applicable mainly for hazardous, flammable, and/or toxic services where a greater degree of reliability is required for the improvement of equipment availability and the reduction of both emissions to the atmosphere and life-cycle sealing costs.

2 It covers seals for pump shaft diameters from 20 mm ( in.) to 110 mm ( in.). This Standard is also applicable to seal spare parts and can be referred to for the upgrading of existing equipment. A classification system for the seal configurations covered by this Standard into categories, types, arrangements, and orientations is provided. This Standard is referenced normatively in API 610. It is applicable to both new and retrofitted pumps and to pumps other than API 610 pumps ( ASME , ASME , and API 676 pumps). This Standard might also be referenced by other machinery standards such as other pumps, compressors, and agitators.

3 Users are cautioned that this Standard is not specifically written to address all of the potential applications that a purchaser may specify. This is especially true for the size envelope specified for API 682 seals. The purchaser and seal vendor shall mutually agree on the features taken from this Standard and used in the application. For ordering information: Online: Phone: 1-800-854-7179 (Toll-free in the and Canada) (+1) 303-397-7056 (Local and International) Fax: (+1) 303-397-2740 API members receive a 30% discount where applicable.

4 ContentsPage1 Scope .. 12 Normative References.. 13 Terms, Definitions, and Symbols.. Terms and Definitions .. Symbols .. 124 Sealing Systems .. seal Categories, Types, and Arrangements .. Objectives.. Specifying and/or Purchasing a Sealing System.. 155 General .. Unit Responsibility .. Dimensions .. 236 Design Requirements .. Common Design Requirements (All Categories).. Design Requirements (Category-specific) .. 457 Specific seal Configurations .. Arrangement 1 Seals.. Arrangement 2 Seals.. Arrangement 3 Seals.

5 528 Accessories .. General .. Piping for seal Auxiliary Systems .. Components of seal Auxiliary Systems (if Specified in Annex G) .. 599 Instrumentation .. General .. Temperature-indicating Gauges .. Thermowells.. Pressure Indicators .. Transmitters and Switches.. Level Indicators .. Flow Instruments .. Relief Valves.. Pressure Control Valves .. Pressure Amplifiers.. 7510 Inspection, Testing, and Preparation for Shipment .. General .. Inspection .. Testing .. Preparation for Shipment .. 8011 Data Transfer.

6 General .. Data Requirement Forms .. Datasheet .. Inspector Checklist .. 82vContentsPageAnnex A (informative) Recommended seal Selection Procedure .. 83 Annex B (informative) Typical Materials and Material Specifications for seal Chamber and Mechanical seal Components .. 111 Annex C (informative) Mechanical Seals Datasheets .. 127 Annex D (informative) seal Codes .. 132 Annex E (normative) Mechanical Seals Data Requirement Forms .. 137 Annex F (informative) Technical Tutorials and Illustrative Calculations.. 140 Annex G (normative) Standard Piping Plans and Auxiliary Hardware.

7 183 Annex H (informative) Inspectors' Checklist for All Seals .. 230 Annex I (normative) seal Qualification Testing Protocol .. 231 Bibliography .. 254 Figures1 seal Configurations.. 162 Arrangement 1: One seal per Cartridge Assembly .. 173 Arrangement 2: Two Seals per Cartridge Assembly with a Liquid Buffer Fluid .. 184 Arrangement 2: Two Seals per Cartridge Assembly with or Without a Gas Buffer Fluid .. 195 Arrangement 3: Two Seals per Cartridge Assembly with a Liquid Barrier Fluid .. 206 Arrangement 3: Two Seals per Cartridge Assembly with a Gas Barrier Fluid .. 217 Arrangement 1 Type A Seals.

8 228 Arrangement 1 Type B Seals .. 229 Arrangement 1 Type C Seals .. 2210 Retention of seal Components in Vacuum Services and Arrangement 3 Inner seal .. 2511 seal Chamber Types .. 2612 seal Chamber Register Concentricity.. 2913 Section Showing seal Gland Plate Shoulder .. 2914 seal Chamber Face Runout .. 3015 Mechanical seal Piping Connections .. 3416 Plastic Plug with Center Tab and Example of Warning Tag .. 3417 seal Chamber/Gland Plate for Vertical Pumps.. 3418 Mating Joint Gasket .. 3519 seal Sleeve Runout .. 3620 Auxiliary Sleeve Arrangement .. 3821 seal Sleeve Attachment by Shrink Disk.

9 3922 seal Sleeve Attachment by Split Ring.. 4023 Clamped Faces .. 4024 Distributed Flush Systems .. 4725 Attachment of Key Drives to Shaft .. 4726 Section Showing Containment- seal Chamber Bushing for 2CW-CS and 2NC-CS Configurations.. 5127 seal Testing Sequence .. seal Selection Logic .. Group II seal Arrangement Selection Chart .. Conversion of mg/m3 to ppmv at 25 C (77 F) and Atmospheric Pressure .. Temperature Correction Factor for Figure .. Relative PV Comparisons for seal Face Combinations .. Estimated Gas Leakage for 50 mm Shaft at bar, Expressed in Normal Liters per Minute.

10 Estimated Liquid (Water) Leakage for 50 mm Shaft at bar, Expressed in Cubic Centimeters per Minute.. Illustration of Alternative Vapor Pressure Margin Calculation Options .. Illustration of Vapor Pressure Margin Calculation Methods as Applied to Propane .. Illustration of Balance Ratio Measurement Points .. Gland Plate Model .. System Model.. Pipe System Friction Curves .. Tubing System Friction Curves .. Circulating Device Performance and System Resistance in Tubing System Curves .. Circulating Device Performance and System Resistance in Pipe System Curves.