A thermostatic radiator valve requires capping off once the radiator is removed, this is because the valve can still open and potentially leak water everywhere. You can easily cap a thermostatic valve off using a 1/2 “ BSP blanking cap and ½” washer (it can be rubber or fibre), or if you don’t have a blanking cap, you can use the nut from a 15mm compression fitting, a 5 pence piece and a rubber or fibre washer. The lockshield valve does not need capping, as it requires tools to open and close it #shorts