20 Pa. C.S. § 3552
When a sum of money is charged upon real or personal property by will, inter vivos trust or decree, and is payable at a future date, the court having jurisdiction of the estate or trust, upon petition of a party in interest and after such notice as it shall direct, aided by the report of a master if necessary, or at the audit of any accounting, may enter a decree not contrary to any expressed provision in the will or trust instrument, exonerating and discharging such portion of the real and personal property charged as to it may seem beyond the amount requisite for providing a sufficient continuing security for the payment of the charge, or may direct that excess income be accumulated for the further protection of the charge, or be distributed to the persons entitled thereto. When an annuity is not restricted by the will or trust instrument to the income of he property charged with its payment, the court may authorize the payment of the annuity from the principal of the property set apart to secure its payment, should income at any time prove insufficient.
20 Pa.C.S. § 3552