'Limp wall' materials for 4kV transformer enclosure

[mingmongmang]

Hi,

I've been tasked with fixing an excessive noise issue from a 4kV transformer enclosure and looking into adding a limp wall layer to the inside of the enclosure to absorb airborn noise. The existing enclosure walls are .11" thk steel and about 6" from the transformer. The transformer is on isolation mounts.

I've read that I need a viscous rubber material sandwiched between two layers of sheet metal to create the limp wall effect. Can anyone recommend a suitable material and give advice on installing? If I go this route it will be done on-site so any advice on adhesives to use would also be useful.

Are there better approaches than using a limp wall to suppress the noise? I'm open to any and all ideas at this point.

Thanks,

Jon Crouch.

 

[Tmoose]

Are there ventilation slots etc in that enclosure?
Can you feel noticeable vibration (or better yet, measure for amplitude and frequency content) the enclosure walls at mid span and at the corners?
Do you know if the enclosure is isolation mounted to the transformer, also if the transformer is on isolators?