Regulating device found in retrieval vehicle (5)
I believe the answer is:
valve
'regulating device' is the definition.
'valve' can be an answer for 'device' (valve is a kind of device). I'm not certain of the 'regulating' bit.
'in retrieval vehicle' is the wordplay.
'in' says the answer is hidden in the clue.
'VALVE' is hidden within 'retrieval vehicle'.
'found' acts as a link.
Can you help me to learn more?
(Other definitions for valve that I've seen before include "Structure with a flap to ensure one-way flow" , "Structure with a flap to insure one-way flow of fluid" , "Device for controlling the flow of a fluid in a pipe" , "Flow regulator" , "Device regulating flow" .)