A few bulkhead questions.

If I have a 1" bulkhead, will standard 1" PVC pipe slip fit the bulkhead? I
gather it will, as the elbow gizmo that came with the bulkhead fits inside
my PVC elbows. Although the bulkhead elbow fits the bulhead rather loosely.

Do I use standard PVC glue to join them or will Silicone do?