Not sure where to post took a gamble here. As seen in the attached pic, there is this piece of rusty flat metal that is attached to the tank to my outside propane tank. It is attached to the pressure relief neck, but there is nothing indicating it has anything to do with it. It's relatively loose and if the wind blows hard enough it'll contact the tank loud enough to hear it . Can anybody tell me what it's function is? If it turn out to be not required (or nobody knows), I'll contact the propane company to confirm the removal of it.

Our house appears to be clogged at the main pipe or air vent. I was about to call the plumber, however, decided to give it another shot snaking outside vent and appears it fixed the issue, at least temporarily. Symptoms: When taking a shower, kitchen sink gargles. Both toilets are very slow to flush. Waste disposal flushes all the crap into utility sink downstairs. When running utility sink, the washer drain gargles a couple feet away. I tried to snake from the basement access hole, but could not pull up anything. When I snaked from outside vent, some crap did come up, however, not as much as I would expect would clog a 3 inch pipe. I could not break loose the floor access holes, however, if experts suggest, I will give it my best. We have town sewer and they okey'ed on their end. Questions: Could the air vent cause this issue? Is it even possible to clog it up with sewer? The reason why I zeroed in on the air vent is when I opened the smaller access hole, toilets started flushing.