27 feature a converter station, which bridges electrical power between AC and DC circuitry and is ubiquitous to HVDC projects worldwide. The converters are located at the IPP station north of Delta, UT, and the Adelanto Converter Station in Adelanto, north of San Bernardino, CA. The heart of the conversion process transpires in clusters of electronic valves that procedurally modify the flow of electricity in a manner similar to switches. The type of valves on Path 27 is thyristor, technology popular in HVDC since the late 1960s. The valve configuration is identical for both converters: 24 stacks about in height of 24 valves apiece (or three "quadruple-valves"), organized into twelve modules—a single valve contains 144 thyristors. As a matter of redundancy, the valves at both terminals are grouped two by six; should one be disabled, the other can pick up the slack above its designated capacity for a limited duration. The entire assemblage is housed in a hangar-like enclosure called a valve hall that protects it from the weather and airborne dust. The valves are affixed on tall insulators that separate them from the interior walls, floor, and ceiling; done to hinder induction and premature grounding, as well as aid cooling. Path 27's valve halls are also fortified against earthquakes. As the IPP converter is adjacent to the power plant, electricity is generally fed into the HVDC line from this terminus. Ingress for power to the system is preceded by a row of transformers that step up the voltage level to 500 . Next, it infiltrates the valve hall through enormous bushings that protect the building from damage caused by arcing. Inside the hall, the valves pipe the electrical flow from AC to DC in a complex process called rectification. On the DC circuitry back outside sits a sequence of filters and reactors that reciprocally serve to cushion the facility from disturbances as a result of power surges. The electricity is then sent on its way down Path 27. The Adelanto Converter Station demarks the receiving end of the HVDC line and has relatively the same layout, but the conversion mechanism is reversed. Beyond another set of reactors and filters, the inpouring power enters the valve hall to be carried over to AC circuitry anew—this is inversion, and it blocks vagrant power on the AC conduit from reaching the valves to enforce unidirectional movement. The electricity advances through a second