53 Pa. Stat. § 7189
Any rule granted under the provisions of this act may be made returnable at such time as the court may direct, either therein or by rule of court, or by special or standing order. All petitions, answers, and replications shall be under oath or affirmation. Answers must be filed and served within fifteen days after service of the petition, and rules and replications must be filed within fifteen days after service of the last of the answers. Replications must be confined to a reply to new matter set forth in the answers.
The facts averred by either party, and not denied in the answer or replication of the other, shall be taken as true in all subsequent proceedings in the cause, without the necessity for proof thereof, unless amended as herein set forth. Any fact necessarily found by the court in finally determining a rule shall also be taken as true in all subsequent proceedings in the cause, without the necessity for proof thereof, unless either party, by writing filed and served at least ten days prior to the time fixed for trial, requires that it be submitted to the jury.
53 P.S. § 7189