Double shut-off valves

Where 100% leaktightness, even to TRD, is demanded then double shut-off butterflies are deployed. Two butterflies or one butterfly with double sealing form an air seal chamber in the closed state into which a barrier medium, e.g. air, is blown. Our technicians calculate the required barrier air volume and pressure such that a 100% leak-tightness is guaranteed for all operational states. With options such as differential pressure measurement for monitoring the leak-tightness, barrier air heating to prevent falling below the dewpoint and a swing-type non-return valve in the barrier air line to protect the blower from the medium, we supply complete and fully functional units.

FunctionShut-off, 100% medium-tight with sealing air
Cross sectionin circular or rectangular execution
Designas flange valve or weld-end valve
Flange connectionto DIN / BS / ANSI / customer specification
Number of leafssingle leaf, multiple leaf
Mediumgaseous, pressure range to 10 bar, temperature range -50 to +1200°C
Explosion protectionoptional
Shaft sealgland packing, also Clean Air Guidelines conformant /O-ring
Leaf sealwithout (sweeping) / metallic striking / soft seal, chambered
Insulationwithout / internally lined / internally clad with fibre insulation / prepared for on-site external insulation
Materialssteel / stainless steel
Actuationelectric / pneumatic / hydraulic / hand lever / also with emergency actuation in the case of power failure