Best way to test new parts?

[LuckyBenski]

I have some less than top quality parts in my spares box, such as reservoirs, and I've got to thinking: When something is new, but cheap, how does one test it to be confident it's OK?

I saw some tube reservoirs from China that are very cheap but you'd think a simple res would be easy to seal. So how would you test it before putting it in a loop?

Is pressure a good test of water tightness? Would it demonstrate its reliability (or lack of) if I pumped some air / water into it?

Any other suggestions?

 

[LuckyBenski]

Good point about the flush - I'd always flush radiators at the least so would probably end up using the reservoir for that.

And good to know about mains water - I've heard of using it on radiators but sounds far too fiddly and messy for me, much prefer to take my time!