Vatac Gate valve
Vatac Gate valves are compact designed and properly machined, which is completely in accordance with most updated International Standards of API 600, ASME B16.34, DIN 3202, GOST or equivalents Vatac offers a broad line of Cast & forged gate valve in both B.B & P.S designs.
A cast gate valve, also known as a sluice valve, is a valve that opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The distinct feature of a knife gate valve is the sealing surfaces between the gate and seats are planar. The gate faces can form a wedge shape or they can be parallel. Typical slab gate valve should never be used for regulating flow, unless they are specifically designed for that purpose. On opening the gate valve, the flow path is enlarged in a highly nonlinear manner with respect to percent of opening. This means that flow rate does not change evenly with stem travel. Also, a partially open gate disk tends to vibrate from the fluid flow. Most of the flow change occurs near shutoff with a relatively high fluid velocity causing disk and seat wear and eventual leakage if used to regulate flow. Typical gate valves are designed to be fully opened or closed. When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low friction loss.
STANDARD FEATURES OF VATAC STEEL GATE VALVES ● LOW FUGITIVE EMISSION SERVICE
Vatac standard Steel Gate Valves are designed and manufactured to ensure leakage of less than 100
ppm (parts per million) of volatile organic compounds. Extensive base line laboratory testing (static and cycle testing) has been performed establishing critical design parameters necessary to achieve low emission sealing in the Vatac stem packing seal area and in the bonnet gasket sealing area, In-house testing procedure has been developed and is periodically performed to ensure that standard product design and manufacturing criteria consistently result in the Vatac Gate Valve meeting a maximum of 100 ppm VOC leakage prior to shipment.
CRITICAL DESIGN AND MANUFACTURING CONTROLS APPLIED TO PRODUCE LOW EMISSION SERVICE GATE VALVES IN VATAC STANDARD PRODUCTS
Stem Straightness and Roundness ■ Stem Surface Finish To Max. 32 Ra
Stuffing Box Surface Finish To Max. 125 Ra ■ Stuffing Box and Gland Cylindricity
Self Centering Gland Design ■ Gland Packing: Die-formed Graphite Rings with Braided
Graphite Top and Bottom Rings.
Bonnet Gaskets
■ Class 150: 316 SS Tanged Clad Graphite ■ Class 300: 316 SS Spiral Wound
■ Class 600 & Higher: Ring Type Joint
LOW EMISSION DESIGN OPTIONS LIVE LOAD PACKING
In services requiring frequent cycling or with high pressure/temperature variations, live loading extends the service life between maintenance periods by requiring less frequent packing gland adjustments. Belleville springs are employed to provide constant packing gland stress. Lantern Ring and Double Packing Set Lantern ring with leak-off fitting connection and double packing stack is optionally available for critical services.
PACKING SYSTEM
Vatac Steel Gate valves use a combination of dieformed flexible graphite and interbraided graphite in a predetermined arrangement to ensure an effective seal. Graphite packing achieves its maximum ability to isolate the atmosphere when it is contained within a chamber that is precise in finish and dimension. Vatac Gate valves are manufactured with stem finishes better than 32 Ra and stuffing box wall finishes for 125 Ra. In addition, stem straightness and taper are closely controlled.
AVAILABLE MODIFICATIONS FOR VATAC STEEL GATE VALVES
Packing and Gasket Changes ■ End Connection Modifications ■ Gear Operator Mounting
Trim Changes ■ Actuation ■ Cryogenic Gas Columns ■ Hand Wheel Extensions
Teflon Disc Inserts ■ Drilled & Tapped Body/Bonnet Connections ■ By-Pass
Pressure Equalizing ■ Acid Shields ■ Oxygen & Chlorine Cleaning & Packaging
Weld End Bore Changes ■ Customer Specified Coatings ■ Chain Wheel Operator ■ Block and Bleed
NDE TESTING AVAILABILITY
Dye Penetrant Test ■ Magnetic Particle Test ■ Radiography
PMI (Positive Material Identification) ■ API Performance Testing
O-RING SEAL BLOCK & BLEED GATE VALVES ● FIRE SAFE, VAPOR TIGHT SHUT-OFF
Should fire occur burning or damaging the O-Ring seal, metal to metal seats will provide an effective fire-safe shut-off.
SERVICE RECOMMENDATIONS
Vatac O-Ring Seal Block and Bleed Gate Valves are recommended for hard to hold services such as butane, kerosene, gasoline, propane, diesel oils, fuel oils, jet fuels, steam, air, natural gas, toluene, hydrogen, helium, and oxygen. Manifold tank farms, LPG areas, and airport fueling facilities provide excellent opportunities for savings with the O-Ring Seal Gate Valves. For effective double block and bleed service, the line media should be free of foreign matter and solids in suspension.
Cast Steel Gate Valvehttp://www.vatacvalve.com/Product/GateValve_Class_246.html
Forged Steel
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