Keg Lids-Interchangeable?

I purchased a keg from one of the pop up adds on this forum. I may have had too many homebrews at the time and forgot who it was purchased from. Anyways, the keg that was shipped to me has a pressure relief valve that cannot be released,ie-no manual bleed. Can I used a lid from another brand of keg or can I modify this one? The keg lid relief valve is moulded into the "frame" on the lid and the pressure cannot be released manually.

Yes, they are.

Sweet, just the answer I was looking for! Now I have a conditioning keg and two serving kegs!