The upper stem is locked by manual or motorized control while the O-ring assures a life-time lubrication. Moreover, a mark is machined on the top part of the stem, which reproduces exactly the disc position, when yhe valve is inserted between the flanges.
The one-piece valve body casting ensures high strength with minimum weight. It can be supplied in a wide choice of materials, for both WAFER and LUG models, so as to meet all possible installation requirements.
The stem has a quare end which fits directly in the disc; hence no fastening elements are needed. This allows the disc to float on the stem and to be self-centering inside the seal so as to form a continuos tight shut-off line with the latter.
Thanks to the special shape of the SIRCA disc, pressure drops and forces of rotation are appreciably reduced. Thanks to the special internal profile of the surface of contact between disc-seat, the reciprocal back pressures ensure tight shutoff.
The resilient seat is vulcanized on metallic support ring. Thanks to its straight-forwar design it is easily replaceable without use of special tools.
Thanks to the special profile of the seat, no seal is required between the flanges.while the O-ring assures a life-time lubrication. Moreover, a mark is machined on the top part of the stem, which reproduces exactly the disc position, when yhe valve is inserted between the flanges.