Piggable Isolation Valve
 
Piggable Isolation Valves are used at any point along a pigged transfer line where pigging components in the main line must be temporarily isolated. Piggable valves are frequently used to isolate the Launching PLR from the transfer line and for isolating product discharge points along a single common pigged transfer line.
 
Piggable valves are specified to have the same internal diameter as the transfer piping to which they are attached and provide smooth passage of the pig through the valve. In most applications a standard "full port" ball valve is available for this application need.
 
In some applications, standard valves are not available for a particular line size which occasionally presents the need to use specialty valves manufactured with internal diameters to match adjacent piping.