The part is called a Thermostat.
What is it? This thermostat controls the coolant flow to the throttle bottle to prevent the throttle body from icing over in colder climates.
If you broke yours (happens all the time, damn thermoplastics) and you joined them with union of some sort you will be totally fine. The only downfall is that your going to be constantly heating the throttle body causing higher IAT's.