Wireline Preventers : Preventers installed on top of the well or drill string as a precautionary measure while running wirelines. The preventer packing will close around the wireline. (RP 53)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}