Valve Insulation Box 1

[mechinspec1]

Dear Experts,

I need advice on below situation about Valve box jacket voids.
During Hot Insulation(100mm thick) of piping works we found that Valve Box's (D type Aluminium box) fabricated larger in size and due to this bigger size there are gaps/voids formed between the Rockwool and metal Jaketing. Contractor says it will not be a problem since the required thickness of insulation material is provided.

 

[btrueblood]

"Contractor says it will not be a problem since the required thickness of insulation material is provided."

...but the bigger box has more surface area to radiate away heat. Either pack in more insulation or have the box built to correct dimensions.

 

[mechinspec1]

Thanks btrueblood, larger surface areas will lead to more radiation loss. but wondering this is the only reason specifications calls for No Gaps/voids between the metal jacket and insulation.