Where are definitions of unfired and direct firing pressure vessel?
U-1(g) and U-1(h) still make me puzzled.
Boiler parts separated by intervening valves such as superheater, reheater, economizer etc., all items above can be constructed under Sec. VIII-1 due to the intervening valves, so how to classify their service condition?
If steam drum is constructed under VIII-1, is it a fired pressure vessel?

Where are definitions of unfired and direct firing pressure vessel?
U-1(g) and U-1(h) still make me puzzled.
Boiler parts separated by intervening valves such as superheater, reheater, economizer etc., all items above can be constructed under Sec. VIII-1 due to the intervening valves, so how to classify their service condition?
If steam drum is constructed under VIII-1, is it a fired pressure vessel?
Where are definitions of unfired and direct firing pressure vessel?
U-1(g) and U-1(h) still make me puzzled.
Boiler parts separated by intervening valves such as superheater, reheater, economizer etc., all items above can be constructed under Sec. VIII-1 due to the intervening valves, so how to classify their service condition?
If steam drum is constructed under VIII-1, is it a fired pressure vessel?


Kimishen,

U-1 (g) and (h) clearly defined fired and unfired pressure vessels.

Okay here's the other definitions.

Fired Pressure Vessel (Boiler) means closed vessel used to heat water or other liquids to generate steam or other vapors under pressure or vacuum by the application of heat resulting from combustion of fuels, electricity, atomic energy or waste gases.

Unfired Pressure Vessel (Pressure Vessel) means an enclosed vessel in which pressure is obtained from an external source, or by applying heat from indirect source or from a direct source other than boilers as defined by U-1 (g)and (h).

Good luck,
leem817

So boiler parts separated by intervening valves shall be fallen into VIII-1 (fired pressure vessel)?
And could you give me a example of unfired steam boil which the terminology is opposite to fire steam boiler?

So boiler parts separated by intervening valves shall be fallen into VIII-1 (fired pressure vessel)?
And could you give me a example of unfired steam boil which the terminology is opposite to fire steam boiler?

Kimishen

Here one example. Electric Boiler.
An electric boiler where heat is applied to the boiler pressure vessel externally by electric heating elements, induction coils, or other electrical means is considered to be fired steam boiler.

An electric boiler where the medium (water) is directly heated by the energy source (electrode type or electric immersion element type) is considered to be unfired steam boiler.

The Code permits manufacturers of electric boiler pressure vessels the option of construction using either the rules of Section 1 or Section VIII-1. Although the requirements of each Section maybe different it has the same level of safety, however the Code does not permit the interchanging of requirements between Sections.

Since the reference of Section 1 for the definition of an unfired steam boiler has been removed, the remainder of the U-1(g) paragraphs have been editorially revised to more clearly state the types of vessels that are not considered unfired steam boiler, example are evaporators, heat exchangers and vessels in which steam is generated but not withdrawn for external use.

Hope this will help you
leem817