Dished and flanged heads

DVAI can provide you any type of tank head while following NFE81 100 norm : GRC (Large Knuckle Radius – DIN28011 – NFE81102), PRC (Small Knuckle Radius NFE81101), fonds MRC (Medium Knuckle Radius NFE81104) and ELL (Elliptical). All these types can be used to manufacture a complete stainless steel tank.

GRC NFE81102

Elliptical

MRC NFE81104

PRC NFE81101

DE: external diameter
E: nominal thickness
RI: spherical radius
RC: knuckle radius
H2: theoretical internal arrow
H1: straight edge height

The dimensions of your tank (diameter, height) are often determined by its useful volume, it is then necessary to know the volume in liters of heads to determine the volume of the shell. As part of the boilermaking, to achieve this first step in the design of your tank, you can know the volume of our heads through our chart below :

If you can not find the appropriate size, contact us for further information.

A dished head is constituted by a spherical cap, a toric element and a cylinder-shaped edge.

• PRC : Small knuckle radius head NFE 81-101 or Shallow head
• MRC : Medium knuckle radius head NFE 81-104
• GRC : Large knuckle radius head NFE 81-102 or Klöpper head, DIN28011
• Elliptical head NFE 81-103 or Korbbogen head, DIN28013

– Expansion length tolerances:

Case of MRC and PRC:
– If De <= 2000: 0/+6 mm – If De > 2000: 0/+10 mm

Case of GRC and ELL:
– If De <= 6000: +/- 0.003 x De – If De > 6000: +/- 0.001 x De

– Thickness tolerances: minimal thickness = 85% of nominal thickness

– Depth tolerances h1 + h2:

Depth <= 6mm : +/- 0.0075 x De Depth > 6mm : +/- 0.01 x De