– General construction similar to VG standard knife gate.
– Bidirectional gate, with two seat gaskets.
– Longer body in two parts assembled by bolts.
– The gate is longer and its lower part rests out of the body, which requires a second system of gland packing.
– The gate contains a hole, which assures:
. in opened position, a complete passage of the fluid without retention zone.
. in closed position, the complete obtu ration.
– This gate is particularly adapted in paper mill, in the exit of pulp, for the recovery of the old paper where the product is mixed with numerous impurities (ex: staples).
– No retention zone: interesting in load or unloading of chemical device (dryer, reactor…).
– Valve tightness even in difficult conditions.
No accumulation of product in the bottom of gate evacuation gorge.
PRINCIPLE OF FUNCTIONING
– The through conduit knife gate valve is composed of a gate containing an opening which moves between two half-bodies.
– When the opening of the gate is aligned with the opening of half-bodies, the valve is opened.
– When the opening is moved in closed zone, the valve is closed.
– The principle of gate movement is similar to the functioning of a «cigar cutter».
All the solutions of actuators, detection and accessories are identical to the VG standard valves.
AGREEMENT AND TESTING
– Manufacture according to the requirements of the European directive 97/23/CE «Equipments under pressure» : category III modulate H (from DN 50 to DN 300).
– Test procedures are established according to NF EN 12266-1, NF EN 12266-2, DIN 3230 and ISO 5208.
– Valves are mounted between flanges by bolts (see pages 100 and 101).
– Between flanges PN 10 following NFE 29203 / BS 450 / ANSI B 16-5 option ASA 150.
FACE TO FACE
According to standard TECOFI.
PRESSURES / TEMPERATURES
– Maximum working pressures:
. DN 50 – 250: 10 bar,
. DN 300 – 400: 6 bar,
. DN 450 – 600: 3.5 bar ,
. DN 700 – 1200: 2.0 bar.
– Maximum working temperatures:
. Nitrile: 80°C,
. EPDM: 110°C.
– Other materials