Number and Length of Speeches. A speaker can speak two times per item for 10 minutes each time. RONR (11th ed.), p. 387, ll. 29-33, p.389, ll. 1-2.
If a member yields the floor before speaking his/her full ten minutes, s/he is presumed to have waived his/her right to the remaining time. RONR (11th ed.), p. 388 ll. 12 - 18
The US House of Representatives has a rule that permits control of all time by a single member or the leaders of the opposing sides of the question.