Catechism of the Catholic Church §1582 — excerpt
As in the case of Baptism and Confirmation this share in Christ's office is granted once for all. the sacrament of Holy Orders, like the other two, confers an indelible spiritual character and cannot be repeated or conferred temporarily.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: Council of Trent: 1 DS 1767 · LG 21 · 28 · 29 · PO 2