Piping systems shall be substantially supported and protected against physical damage and excessive stresses arising from settlement, vibration, expansion, or contraction. The installation of nonmetallic piping shall be in accordance with the manufacturer's instructions.
34 Pa. Code § 14a.55
This section cited in 34 Pa. Code § 14a.8 (relating to vents); 34 Pa. Code § 14a.51 (relating to scope and application); 34 Pa. Code § 14a.52 (relating to general design specifications); and 34 Pa. Code § 14a.161 (relating to general provisions).