The solid metal or metal-graphite sealing for the double and triple offset butterfly valves. Available for valves with seat surface integral with the body and sealing ring in the disc assembly or sealing ring in the body and seat surface in the disc.
Dimensions, materials upon request.
SPETORING® RD-E and RT-E are manufactured in sizing up to DN 3000 (or 120” adequately). Faying surface roughness Ra=1.6. Standard materials used to manufacture are austenitic steel (304, 316L, 321 etc.), Duplex, Super Duplex, alloy C-276, and others to respective order. The graphite material used is always Sigraflex® a s s hown i n t he T able o f General Informations about available graphite grades. SPETORING® RD-E and SPETORING® RT-E are designed to particular types of fittings, and usually are constructed according to drawings of their manufacturer. In some specific cases, SPETECH® can reconstruct the throttle gland basing on dimensions of the body/casing (it refers mostly to models withdrawn from production). Regarding a ‘sandwich’ design, the number of steel interlayers is usually 3 or 4, however in case of large diameters the number can be even 12. Thickness of graphite is usually between 0.3÷1mm.
Alternatively to RD-E and RT-E s eals p resented a bove i nside b utterfly valves another solution may be installed. An optional solution available both for 2-offset and 3-offset valves is especially shaped elastic metal ring called SPETORING® RL-S. Shape of the SPETORING® RL-S can be given either by spinning or by machining. Springiness, mechanical strengths and other features may be modified by specific construction, shape and wide choice from many available materials.
SPETORING® RL-S i s n ormally i nstalled i n t he b ody o f t he v alve a nd (what is different from sandwich construction of RDE and RTE rings) RL-S seal is resistant to any potential erosion due to lack of any soft material inside. But in the same moment (and in some of construction options), the RL-S seal is performing with much higher elasticity and self-energizing effect. Such features make the this solution very useful to work in high / frequently changing pressure and temperature.
Details of this SPETORING® RL-S (construction / geometry / material used) always are settled in co-operation between Spetech and valve manufacturer. Such solution we deliver for valves with size up DN3000 (or 120” adequately).