Well a logic_relay isn't really needed Daniel.
Relays are mostly for organization and preventable events (since you can disable a relay)
As Grimmy said, every entity has it's own in/output system which you can use in an even better way than in HL1 to trigger multiple events since now you can also change the conditions of when it should be triggered based on entity activity (like, when the entity does THIS, then trigger THAT)