[Code of Federal Regulations] [Title 46, Volume 2] [Revised as of October 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 46CFR53.05-1] [Page 137] TITLE 46--SHIPPING CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PART 53_HEATING BOILERS--Table of Contents Subpart 53.05_Pressure Relieving Devices (Article 4) Sec. 53.05-1 Safety valve requirements for steam boilers (modifies HG-400 and HG-401). Source: CGD 81-79, 50 FR 9435, Mar. 8, 1985, unless otherwise noted. (a) The pressure relief valve requirements and the safety valve requirements for steam boilers must be as indicated in HG-400 and HG-401 except as noted otherwise in this section. (b) Each steam boiler must have at least one safety valve.