The Anti-Tamper Lock (ATL) reduces the risk of human error or deliberate tampering. Operation of the ATL is simple: the normal condition of the device in service is locked, with the handwheel free-rotating. Operation involves three steps: first a coded key from the control authority is inserted, engaging the drive; second, the valve is operated to the desired position; finally, the key is removed and the valve is locked in the desired position. Since the lock base adapter is machined to suit the host equipment costs are significantly reduced. Also, as this process replaces existing handwheels or levers, the integrity of pressure envelopes is not compromised in any way. As the unit is only installed and commissioned once, permit to work and lock-out/tag-out authorities can focus their attention on other issues. The ATL’s housing is stainless steel coated with yellow polyester resin. For safety applications the internal components are manufactured from stainless steel 304, with acetyl bearings, while for security applications these components are manufactured from hardened steel, with a protective security “skirt”. Both versions can operate in temperatures ranging from -58F to +212F.