SGV Wedge Gate Valve
Gate valve can only be fully open/close, and can not be used as adjusting valve.
In a wedge gate, the seats are not parallel, but taper inward from top to bottom. The discs are also tapered.The trim of wedge gate valve is wedge, which is vertical to medium flow direction. When the discs are forced into the seats, the wedging action provides the sealing force. That is effective for sealing, but one of the drawbacks of a wedge gate is the discs can get ‘stuck’ in the seat, especially if there is a great change in system temperature from when the valve is closed.
Wedge gate valve can be a unique type called inflexible disc; and can also be a flexible wedge.Gate valve under low pressure occasion, disc is forced to set to guarantee sealing; while disc is forced to contact another seat by high pressure condition. There is a slot structure inside the cavity to make sure the disc will not rotate under pressure, and also guarantee there is no friction before close position between seat and disc, thus reduces frictions on sealing face.
Design standards: API 600、GB/T 12234 and other
DN: 1/2 “-48”, DN15-DN1200
Body material: carbon steel, stainless steel, alloy etc.ASTM A216 WCB,A217 WC6,A351 CF8,A351 CF8M,A351 CF3,A351 CF3M,A351 CN7M
Operation: manual, gear, handwheel,hydraulic, motor etc.
OS&Y,Rising stem,Flexible Wedge Gate Valve,Solid Wedge Gate Valve
Bolted Bonnet,Threaded or welded seat ring, Renewable seat ring, Forged disc gate valve for small size,cast disc gate valve for big size
Wedge gate valve of Sangong has following advantages
1. Product fabrication is strictly according to API 600, full port design, on full open position, valve disc is higher that flow direction to guarantee flow smoothly, reduce pressure loss, high transmission efficiency.
2. For carbon material valve, seat is forged, high density, good sealing capacity. Sealing face use 13Cr or Stellite hard alloy material, overlay net thickness is over 2mm, valve seat is threaded or welded on the valve body, easy to maintain and dissemble.
3. Adopt rising stem, stem and disc is connected by a T shaped groove, T head and stem is forged together to guarantee enough connection strength. Flexible disc structure can avoid stuck caused by heat inflation
4. Back seal design will protect packing when valve is fully opened. Packing is flexible graphite, good sealing capacity, and also venting system is available. Packing bush and gland are ball structure, pressure process will enable the stem to automatically centralized, avoid stem stuck.
5. Bolted bonnet structure and thick hex nut fastening parts will ensure reliable function. Gasket adopt flexible graphite twist stainless steel or octagonal ring to get good sealing effect
6. Top entry nut design assures that, when the valve is open, even if demount the hand-wheel, stem and disc will not fall down. Stem is made by Aluminum bronze, and both sides set bearing, all this made the valve easy to operate.