... , mill, manufacturer, supplier, factory, wholesale, cheap Instrument DBB Ball ValveHuachao manufactures a variety of instrument Double Block and Bleed ... instrument Double Block and Bleed Valves feature either needle or ball valves depending on our customer’s requirements and are ... )Valve Type: Metal to Metal seated needle valve or soft seated ball valveSpindle: Anti-blow out spindleTypes: 1D type, ...