A safety clamp that can be positively locked ensures that only authorized personnel have access to the clamp. It is designed for use with hazardous high-temperature piping, lines associated with steam, and CIP/SIP cleaning processes. The hex-head nut that secures the clamp is covered by an extended shroud that accepts a small combination lock or key lock. This prevents a hex wrench from reaching the head, making unauthorized access virtually impossible. The clamps are formed of 316 stainless steel and 304 stainless steel is optional. Standard sizes range from 0.5 to 4" with custom sizes available.