Butterfly Valves:

Double-flanged, Lug-and Wafer-type

API STANDARD 609

EIGHTH EDITION, FEBRUARY 2016

API MONOGRAM PROGRAM EFFECTIVE DATE: AUGUST 1, 2016

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Foreword

This standard is a purchase specification for butterfly valves designed for installation between flanges specified in ASME B16.1, ASME B16.5, ASME B16.24, and ASME B16.42, Classes 125-600; MSS SP-44, Class 150; and ASME

B16.47, Series A (was MSS SP-44 except for certain materials) or Series B (was API 605), Class 150 for the NPS sizes defined herein.

This standard requires the purchaser to specify certain details and features. Although it is recognized that the purchaser may desire to modify, delete, or amplify sections of this standard, it is strongly recommended that such modifications, deletions, and amplifications be made by supplementing this standard, rather than by rewriting or incorporating sections thereof into another complete standard.

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Contents

Page

1. Scope 1

2. Normative References 1

3. Terms and Definitions 2

4. Pressure-temperature Ratings 2

   1. Valve Rating 2

   2. Shell Rating 3

   3. Seat Rating 3

   4. Differential Pressure Rating 3

5. Design 4

   1. General 4

   2. Body 4

   3. Face-to-face Dimensions 5

   4. Disc Clearance 7

   5. Shaft and Shaft Seals 8

   6. Piping Connection External Bolt Holes 8

   7. Valve Body Seat Retainer—Category B Valves Only 8

   8. Operating Mechanisms 9

   9. Electrical Continuity 10

   10. Packing Gland Bolting—Category B Valves Only 10

6. Materials 11

   1. Body 11

   2. Process Wetted Parts 11

   3. Packing or Shaft Seal Materials 11

   4. Gland Bolting 11

   5. Operating Mechanisms—Category B Valves Only 11

7. Examination, Inspection and Testing 11

   1. Examination Requirements 11

   2. Inspection by the Purchaser 11

   3. Production Pressure Tests 11

   4. De-rated Valve Type Testing 11

   5. Electrical Continuity Valve Type Testing 12

   6. Repair of Defects 12

8. Markings 12

9. Packaging and Shipping 13

   1. Coatings 13

   2. Shaft Packing 13

   3. Packaging 13

   4. Spare Parts 13

10. Purchase Order Information 14

Page

Annex A (informative) Use of API Monogram by Licensees 15

Annex B (informative) Information to be Specified by Purchaser 18

Annex C (informative) Typical Butterfly Valve Construction and Nomenclature 20

Annex D (normative) Disc-to-pipe Clearances 24

Bibliography 28

Figures

1. External Bolting Options for Lug- and Wafer-type Valves 9

2. Limitations for Flange Face Interruptions that Fall Within the Gasket Seating Area (NPS 6 through NPS 48) 10

1. Typical Concentric-type 20

2. Typical Single Offset-type Construction (Category B) 21

3. Typical Double Offset-type Construction (Category B) 22

4. Typical Triple Offset-type Construction (Category B) 23

1. Typical Concentric-type Construction (Category A) 25

2. Typical Eccentric-type Construction (Category B) 26

Tables

1. Minimum Seat Pressure-temperature Ratings for Category B Valves with PTFE or RPTFE Seats 3

2. Face-to-face Dimensions for Category A Valves (Lug- and Wafer-type) 5

3A Face-to-face Dimensions for Category B Valves, (Lug- and Wafer-type) 6

3B Face-to-face Dimensions for Category B Valves, (Double-flanged Long Pattern) 6

3C Face-to-face Dimensions for Category B Valves, (Double-flanged Short Pattern) 7

1. Nominal Radial Clearances 25

2. Relationship of Unlined Steel Pipe Schedule to Valve Category, Size, and ASME Class 27

Butterfly Valves: Double-flanged, Lug-and Wafer-type

1. Scope

   1. This standard covers design, materials, face-to-face dimensions, pressure-temperature ratings, and examination, inspection and test requirements for gray iron, ductile iron, bronze, steel, nickel-based alloy, or special alloy butterfly valves.

      
      

   2. If product is supplied bearing the API Monogram and manufactured at a facility licensed by API, the requirements of Annex A apply.

      
      

   3. The following two categories of butterfly valves are included.

      
      

      1. Category A—Manufacturer’s rated cold working pressure (CWP) butterfly valves, usually with a concentric disc and seat configuration. Sizes covered are NPS 2 to NPS 48 for valves having ASME Class 125 or Class 150 flange bolting patterns.

         
         

      2. Category B—ASME Class and pressure-temperature rated butterfly valves that have an offset seat and either an eccentric or a concentric disc configuration. These valves may have a seat rating less than the body rating. Sizes covered are listed below.

      
      

      • For lug and wafer, Class 150: NPS 3 to NPS 48.

        
        

      • For lug and wafer, Class 300 and Class 600: NPS 3 to NPS 48.

        
        

      • For double-flanged long pattern, Class 150, 300, and 600: NPS 3 to NPS 36.

        
        

      • For double-flanged short pattern, Class 150 and Class 300: NPS 3 to NPS 48.

        
        

      • For double-flanged short pattern, Class 600: NPS 3 to NPS 24. Information to be specified by the purchaser is shown in Annex B.

   4. Valve configurations include double flanged, lug- and wafer-type with facings that permits installation between ASME and MSS flanges that conform to the standards and specifications listed in Section 2. Typical valve construction and nomenclature for valve parts are shown in Annex C.

      
      

2. Normative References

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. Text in brackets after a publication title indicates a restriction on the classes to which the publication applies.

API Standard 598, Valve Inspection and Testing

API Standard 607, Fire Test for Quarter-turn Valves and Valves Equipped with Nonmetallic Seats

ASME B1.1 1, Unified Inch Screw Threads [UN and UNR Thread Form] ASME B16.1, Gray Iron Pipe Flanges and Flanged Fittings

1 ASME International, 3 Park Avenue, New York, New York 10016-5990, www.asme.org.

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