Danfoss RLV-D Radiator Drain Off Tail Piece Nickel TRV 003L010500. This is an inline drain-off tail piece for radiator valves. It is nickel plated and features a 1/2" BSP connection for the radiator and a 1/2" swivel connection for the valve. The Danfoss drain-off tail piece can be used to convert a standard lockshield valve into a drain-off lockshield, allowing for the draining of individual radiators if required. This eliminates the need for a full system drain, especially when changing individual radiators. It is a great addition to Danfoss TRV and lockshield packs. The Danfoss Randall RLV-D Drain-off Tail Piece allows for simple local drainage at the radiator.