Pressure Vessels Heads

What is Mean By Pressure Vessels Heads :

It is major Part of Pressure Vessel which closes ends of the cylindrical section or shell of the pressure vessel is called as Pressure Vessels Heads. There are various common names are used for Pressure Vessels Heads which are Dish Ends, Formed Heads, End Closure, End Caps, Vessel Ends, Vessel Caps etc. but most Common name is Dish ends.

Types of Pressure Vessels Heads :

There are four basic types of pressure vessels heads or Dish ends is most widely used in fabrication of Pressure Vessels.

  1. Flat Heads
  2. Ellipsoidal Heads
  3. Toripherical Heads or Flange and Dished Heads
  4. Hemipherical Heads

Flat Heads :

It is the simplest form of the pressure vessels heads but it has less usefulness in pressure vessels heads. So it is not preferred as much as of others because it has less pressure withstanding capacity than the other types of heads due to lower radial section is available for pressure distribution. So maximum exposure is comes on flat section so it is not economical.

Flat Heads

Commonly Used terms in the Flat Head is Flat Head Inside Diameter (ID), Knuckle Radius (R), Dish End Total Height (H) and Straight Face (SF). Flat Heads General Drawing Representation is shown in above Drawing.

Ellipsoidal Heads :

It is a most widely used Pressure Vessel Heads. It has wider Radial section is available for pressure distribution.it withstand maximum pressure as compared to other heads. So it is most preferred pressure vessels heads. for same design condition, Dish end Thickness of ellipsoidal heads is approximately equals to shell thickness so it is most economical heads. Generally most used Ellipsoidal Heads Configuration is as per 2:1 Ellipsoidal Section.

2:1 Ellipsoidal Heads

Commonly Used Terms in 2:1 Ellipsoidal Heads is Inside Diameter (ID), Crown Radius (C.R), Knuckle Radius (K.R), Dish End Total Height (H) and Straight Face (SF). 2:1 Ellipsoidal Head General Drawing Representation is shown in above Drawing. Ellipsoidal Heads required more time of forming as compared to Flat Heads and Torispherical Heads. It is Most Economical Pressure Vessels Heads.

Torispherical Heads or Flange and Dished Heads :

It is also most widely used heads. It also has more radial section for pressure distribution so it also withstand maximum pressure but lower than ellipsoidal Heads. So that it is less economical than ellipsoidal heads but it also widely use due to lower time required for forming than the ellipsoidal heads.

So that for same design condition, Torispherical Heads Thickness is nearly 1.77 times the Shell Thickness for same Design Pressure and Temperature.

Torispherical Heads

Commonly Used Terms in Torispherical Heads is Inside Diameter (ID), Crown Radius (C.R), Knuckle Radius (K.R), Dish End Total Height (H) and Straight Face (SF). Torispherical Head General Drawing Representation is shown in above Drawing.

It required less time of forming that ellipsoidal heads so it also more preferred heads due to simplicity of this heads. This Heads is also Called as Flange and Dished Heads.

Hemispherical Heads:

This Head or Dish end is also used in pressure vessels fabrication. It has Maximum Radial Section is available than the other types of heads. Due to this it has maximum pressure distribution area is available.So that, for Same Design Condition Hemi Heads Thickness is approximately half of the shell Thickness for same pressure and Temperature.

So it is most economical Heads than the other types of Heads but it required maximum time of forming.

Hemispherical Heads

Commonly used terms in Hemi Heads is Inside Diameter (ID), Crown Radius (R), Dish end Total Height (H) and Straight Face (SF). Choice of Dish Ends is Depends upon Design Conditions and Their Applicability of Pressure Vessels Heads.

This are the four Basic Types of Dish ends are used in Pressure Vessels Fabrication. Most of the Dish end terms are calculated by using standard relationships with their inside diameter. On the Part of fabrication Point of View We have to Calculate various terms. This terms includes Dish End Terms, Blank Diameter, Weight, Surface Area, Volume Calculations are required in fabrication of Dish Ends.

Letsfab is continuously working to digitize fabrication techniques, so we had developed many tools for fabrication that save time and cost. To get this tools visit our app page from menu-bar or click here

If you want sharpen your knowledge in Pressure Vessels Heads then learn from Our 21 Days Video Course for Becoming Expert in Pressure Vessels Heads or Dish Ends or Formed Heads or End Closure or End Cap. To Get in Discounted Price Click here…

Imran Pinjara

Author of Book " Master in Fabrication Layout Development " Published worldwide. Founder and CEO of Let'sFab Educational Services. More than 8 Years of Professional Experience in Field of Pressure Vessel, Heat Ex changer, Storage Tanks, Piping and other Process Equipment Fabrication Industry. He had worked in many Fabrication Industry from small workshop to MNC Company. He had Completed PGDM in Process Piping Design and Engineering as per ASME B31.3 and Bachelor of Mechanical Engineering.

Leave a Reply