Dry Gas Dust Filter

Hi,

i have doubt on UW-11 a (3) requirements.All butt welds in the shell and heads of unfired steam boilers having design pressures exceeding 50 psi (350 kPa).

have pressure vessel(Dry Gas dust filter) with internal pressure 800 psi, i red the defination of unfired steam boilers which says,

The following pressure vessels in which steam is generated shall not be considered as unfired steam boilers, and shall be constructed in accordance with the rules of this Division:U-1(g)(2)(a) vessels known as evaporators or heat exchangers;

U-1(g)(2)(b) vessels in which steam is generated by the use of heat resulting from operation of a processing system containing a number of pressure vessels such as used in the manufacture of chemical and petroleum products;

U-1(g)(2)(c)

vessels in which steam is generated but not withdrawn for external use.

I have discussed with my manager, he told that it is not come under the requirements Rt is not applicable, But the pressure is high around 800 psig, shell in considered full radioraphy or not, because its the matter of safety.