Stainless Steel BSP Ball Valves are used in applications that don't require the use of sanitary grade fittings. They are also normally used in pipe applications, not tube, BSP fittings are often referred to as WOG fittings (water, oil, gas fittings).

Ball valves are durable and usually work to achieve perfect shut off even after years of disuse. They are therefore an excellent choice for shut off applications (and are often preferred to globe valves. They do not offer the fine control that may be necessary in throttling applications but are sometimes used for this purpose. (Wikipedia)