The Kingston model 118CSS high-capacity safety valve is an ASME code certified, precision machined brass valve with a hard seat. A hard seat safety relief valve is a metal-to-metal seated valve, which usually uses a metal disc or ball as the internal sealing surface against the orifice or internal passageway in a safety relief valve. Hard seat safety relief valves are excellent in corrosive or extremely high temperature applications. This Kingston safety valve is NOT adjustable. This valve features a stainless-steel ball for durability, a pull ring for manual testing, and is designed to flow at extremely high volumes. The Kingston model 118CSS, like every Kingston safety valve, is set and tested at the factory for quality and dependability. The 118CSS safety valve bodies are stamped with both the UV and NB symbols.