This is complex question I can give you some approximate answers....

1)Yes and no the relief valve may simmer or chatter before lifting. When or if this occurs think of a pogo stick. Lift, close, lift, close.... until a final lift occurs. So a relief valve in many ways can be nastier than a rupture disc.


2)Yes

3)Hmmm think of the shock wave as it travels down the system. When it first enters an elbow pair it creates an unbalanced force in that pair. When it gets to the far elbow of that pair the unbalnced force nearly disappears. So the force unbalance travels down the pairs one after another until the end.

This means that A)The longer the distance between the elbow pairs the more time the unbalanced force is applied and therefore the greater the piping system will participate in it.

B)The outlet of the system if it is open to atmosphere will behave in a fashion as discussed in B31.1

Finally do a search on this forum you will a plethora of advice.