Drain Valve Between Two Valves

This is very much confusing for me.
In P&ID it shows a gate valve and a check valve. the direction of flow is from check valve towards gate valve. line is to be routed for steam out. P&ID shows a process drain in between of these.
Is there any reason behind providing this drain? If yes plz somebody can explain?

In the same P&ID at another place again the same valves. but direction of flow is opposite. i.e. from gate valve to check valve. at this situatuin there is no drain valve in between of them but there is a drain after check valve. Does we require a drain valve between two valve here also?

Be sure that in both the cases the routing is such that you can not sandwich the valves. and service to flow is steam for steamout purpose

waitning for response

Thank You
Siddharth Jain

JOP sorry for late response.
Yes the Line spec is flanged but size is only 2".
Because of some reasons I cannot put the valves in sandwitch position.

Thanks

“Theoretically” in the first situation you could have residual pressure/condensate trapped between the check valve the block valve …”IF” the block valve was closed. So you would need a drain or blow-down valve between those two points, before you broke the line connection at that point for any maintenance operation(s). …In the second case the check valve would not trap any pressure so the drain/blow-down could be down stream of the check.
However in the real world I don’t believe a flapper on the check would seal well enough to trap a really high pressured commodity (except a "heavy" crude or similuar). BUT I’ve seen where a ¼” weep holes have been drilled in the check valve flapper to eliminate that possibility. JOP’s suggestion of a bleed ring to place a drain/blow-down valve in that location is a good one and economical too. We use them a lot in the oil fields I work in. IMHO