Minimum Radius of Pipe or Tube Bending

In Bending a pipe or Tube Outer Part of bend is Stretched and Inner part is compressed Due to this stresses pipe or tube can be flatten or Collapse.

To avoid flatten and collapsing Pipe or Tube minimum radius of bending to be equal 3.5 to 4 times diameter for standard pipe  and 2.5 to 4 diameter for Extra Heavy pipe.

so while bending of Tube or Pipe we have to keep in mind minimum radius.

General Guaidline for Fabrication of Pressure Vessel

1. Code of construction of Pressure Vessel should be noted on Mechanical Data Sheet or Fabrication Drawing.
2. Latest Applicable Code of Construction Shall be made in all aspects.
3. Design and fabrication Drawing should be approved by the client before starting of fabrication of pressure vessel.
4. Thickness Indicated on fabrication drawing shall be minimum Thickness and shall be achieved after fabrication or machining.
5. Any Change in Thickness on higher side shall be acceptable but written approval shall be taken by Client before commencing of further work.
6. Tolerance for fabrication shall be maintain within limits given by the client.
7. Tested Material Should be used in fabrication of Pressure vessel.
8. All External weld Shall be wire brush and weld spatter remove from joints completely.
9. Vessel Shall be Cleaned from inside and all Dust,Dirt,Slag etc shall be removed before hydro testing of vessel.
10. Vessel Shall be dried after Hydro testing.
11. All Internal part preferably be of removable type and maximum weight of the individual piece shall not exceeds 20 kg.Unless noted otherwise on Mechanical datasheet .
12. Only Qualified Welder Shall be Deployed for Fabrication of pressure vessels.
13. Whenever Spot Radiography Specified on the Drawing it means that minimum 10% radiography of Longitudinal and Circumferential Seam. & 100% Radiography of all "T" joints.
14. Nozzle Neck Shall be Made from Seamless Pipe & If Nozzle fabricated from Plate then Weld seam shall be 100 % Radio graphed.
15. Dish end Shall be normally made from single plate. large sized Dish end may be fabricated by joining plates. this joint shall be 100% radiography after forming. Joint Location and Detail Indicated on fabrication Drawing & "T" Joint to be avoided.
16. Internal Coil,Suction Heater,External Limpet Coil Shall be separately hydro tested When main Shell is not under hydro tested.
17. All Manhole Cover or Blind Flanges weighing more than 30 Kg that shall be provided with Davits and hinges.

PRESSURE VESSEL,BOILER,TANKS,HEAT EX-CHANGER AND PIPING CODES,STANDARDS,SPECIFICATION

PRESSURE VESSEL,BOILER,TANKS,HEAT EX-CHANGER AND PIPING CODES.

PRESSURE VESSEL AND BOILERS

ASME BOILER AND PRESSURE VESSEL CODE

• SECTION I - POWER BOILERS.
• SECTION II - MATERIALS.
• SECTION III - NUCLEAR POWER PLANT COMPONENTS.
• SECTION IV - HEATING BOILERS.
• SECTION V - NONDESTRUCTIVE EXAMINATION.
• SECTION VI - RECOMMENDED RULES FOR CARE AND OPERATION OF HEATING BOILERS.
• SECTION VII - RECOMMENDED RULES FOR CARE OF  POWER BOILERS.
• SECTION VIII - PRESSURE VESSELS ( DIV 1, DIV 2,  DIV 3 ).
• SECTION IX - WELDING AND BRAZING QUALIFICATION.
• SECTION X - FIBER GLASS REINFORCED PLASTIC PRESSURE VESSEL.
• SECTION XI - RULES FOR IN-SERVICE INSPECTION OF NUCLEAR POWER PLANT COMPONENTS

TANKS

AMERICAN PETROLEUM INSTITUTE ( API ) 

• SPEC 12 B - SPECIFICATION FOR BOLTED TANK FOR STORAGE OF PRODUCTION OF LIQUIDS.
• SPEC 12 D - SPECIFICATION FOR FIELD WELDED TANK FOR STORAGE OF         PRODUCTION OF LIQUIDS.
• SPEC 12 F - SPECIFICATION FOR SHOP WELDED TANK FOR STORAGE OF                 PRODUCTION OF LIQUIDS.
• STD 620 - RECOMMENDED RULES FOR DESIGN AND CONSTRUCTION OF LARGE WELDED, LOW PRESSURE TANK.
• STD 650 - WELDED STEEL TANK FOR OIL STORAGE.

UNDERWRITERS LABORATORIES,INC. (UL)

• NO 142 - STEEL ABOVE GROUND TANKS FOR FLAMMABLE AND COMBUSTIBLE   LIQUIDS. 
• NO 58 - STEEL UNDERGROUND TANKS FOR FLAMMABLE AND COMBUSTIBLE     LIQUIDS.

AMERICAN WATER WORKS ASSOCIATION (AWWA)

• NO 30 - FLAMMABLE AND COMBUSTIBLE LIQUID CODE.
• NO 58 - LIQUEFIED PETROLEUM GASES,STORAGE AND HANDLING.
• NO 59 - LIQUEFIED PETROLEUM GASES AT UTILITY GAS PLANTS.

HEAT EX-CHANGERS

• TEMA - TUBULAR EX-CHANGER MANUFACTURES ASSOCIATION.
• EJMA - EXPANSION JOINT MANUFACTURERS ASSOCIATION.

PIPING

AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)

• B 31.1 - POWER PIPING.
• B 31.2 - FUEL GAS PIING.
• B 31.3 - CHEMICAL PLANT AND PETROLEUM REFINERY PIPING.
• B 31.4 - LIQUID PETROLEUM TRANSPORTING PIPING SYSTEM.
• B 31.5 - REFRIGERATION PIPING.
• B 31.8 - GAS TRANSPORTATION AND DISTRIBUTION PIPING SYSTEM.