Interlocks type QL






QL valve interlocks suit all types of lever operated quarter turn valves, including ball, butterfly, and plug valves. Available in single key (QL1) or double key (QL2) versions, locking the valve in either the open or closed position, or if the QL2 version is specified, the valve can be locked in both the open and closed position, forming part of a comprehensive range of process interlock safety systems. Available with ‘tailor made’ concentric mounted bespoke valve attachments.


The interlocks can be fitted to the valve during live process, without the need to shut-down the system, nor does it compromise the certified pressure envelope of the system. The lock body is permanently marked with the desired plant identifiers or ‘tag’ numbers. When using Sofis (SFC) interlocks, operators are compelled to follow the correct sequence of operation of all valves within the interlock sequence.