Heavy brass thing

[nathan104]

I cant figure out what this thing is. Its heavy, probably around 6 lbs. As you can see in the picture, inside the large hole is a semi hard membrane across it. Any ideas?

 

[Bigcypresshunter]

View attachment 1331135

It looks as if you removed the diaphragm and there were no electric parts inside? Is this true? Can you show me how the micro switch was connected?

With no coil or wires inside, I think the diaphragm may have worked from pressure.

 

[Bruce R]

Just like a pressure switch on a shallow well pump or an air compressor., just bigger.

 

[Bigcypresshunter]

With no electric parts inside i think it would have to be air or liquid pressure operated diaphragm

 

[nathan104]

Sorry, the micro switch was inside behind the diaphragm. There was a lot of corrosion inside so there may have been other stuff at some point.

The serial number I cant quite make out. I believe it is 9981506 or 99B1506 or 8981506 or 89B1506. Ive tried pencil rubbings but still cant make it out for sure. The other spot with the numbers I cant make out at all.

Yes, the bolts are stainless steel.