Piping Questions

1. What factors to consider for site selection? Ans : District classification, Transportation facilities, Manpower availability, industrial infrastructure, community infrastructure, availability of raw water, effluent disposal, availability of power, availability of industrial gas, site size and nature, ecology and pollution. 2. What are different standards? Ans : Most commonly use standards are as follows: Sr. Standard Description 1. ANSI B18.2 Square and hexagola head bolts and nuts 2. ANSI B16.3 Malleable iron threaded fittings 3. ANSI B16.4 Cast iron threaded fittings. 4. ANSI B16.9 Steel buttwelding fittings 5. ANSI B16.11 Forged steel socketwelding and threaded fittings 6. ANSI B16.25 Buttwelding ends 7. ANSI B16.28 Short elbow radius and returns 8. MSS-SP-43 Stainless steel buttweld fittings 9. MSS-SP-83 Pipe Unions 10. API 605 Large diameter carbon steel flanges 11. ANSI B16.1 Cast iron pipe flanges and flanged fittings 12. ANSI B16.5 Steel pipe flanges and flanged fittings 13. ANSI B16.47 Large diameter steel pipe flanges and flanged fitts. 14. ANSI B16.20 Ring joint gaskets and grooves for pipe flanges 15. ANSI B16.21 Non metallic gaskets for pipe flanges 16. API 601 Metallic gasket for refinery piping. 17. API 5L Specification for line pipe. 18. ANSI B36.10 Welded and seamless wrought steel pipes 19. ANSI B36.19 Welded and seamless austenitic stainless steel pipe 20. ANSI B16.10 Face to face and end to end dimensions of valves 21. ANSI B16.34 Steel valves, flanged and buttwelding ends. 3. What are various temporary closures for lines? Ans : Line blind valve, line blind, spectacle plate, double block and bleed, blind flanges replacing a removable spool. 4. Where jacked screwed flange is used ? Ans : For spectacle discs, one flange is jacked screw flange. This flange has two jacked screws 180 degree apart which are used to create sufficient space between flange for easy removal and placement of line blind or spectacle blind.

5. What is double block and bleed? Ans : Two valves with bleed ring in between with a bleed valve connected to the hole of bleed ring. 6. Where blind flange is used ? Ans : It is used with view to future expansion of the piping system, or for cleaning, inspection etc.