Unstayed Heads, UG 34

[weldtek]

Greetings,
Just joined and this is my first post. Will someone help me understand the meaning of the expression 'Unstayed', as pertaining to flat heads. Are some heads stayed, and if so, what's the difference between stayed and unstayed?
Thanks,

 

[unclesyd]

Please give a little more information as to your application and if it pertains to a some Code or Standard there is a lengthy calculation and certain installation procedures required.

Simply; An Unstayed head is head, mostly concerns flat plat but can be other shapes, attached to a vessel around it's periphery with no added support.

A Stayed head has stay rods/bolts attached to the head that to prevent the head from deforming or failing from either internal or external pressure.

 

[rjoaks]

rjoaks
Stayed heads are used in fire tube boilers where the tubes, burner flue or bolt/rods hold the heads from deforming due to pressure.
Unstayed heade are heads which are designed with no support.