No Slide TitleFunction Of Check Valve “ THE CHECK VALVE ( NRV OR REFLUX VALVE ) IS A PROTECTIVE DEVICE TO PREVENT REVERSE RUN OF EQUIPMENT AND IS THERE TO SLOW DOWN THE FLOW IN THE REVERSE DIRECTION OR TO CUT THE MASS FLOW RATE DOWN TO ABOUT 1 TO 5 % IN THE BACKWARD DIRECTION OF W HAT THE FORWARD FLOW IS”. - RONALD C. MERRICK Valve Slamming Damage & Damage control mechanism * * * Dual Plate Check Valve Valve remains fully open for flow velocity above V min. Flow Velocity Vs Time Graph * 3.unknown Home VISUALISE PRESENT TIME DOORS WITH SIDE HINGES AND OLD TIME TOP HINGED DOORS Lower Pressure Drop F = 0.75(Spring Force) + The weight of the plates does not increase the force required. The design of the dual plate check valve divides the total force in half, since each plate covers only 1/2 the area of a swing check disc. With 1/2 the force on each plate, it requires only 1/2 the thickness of the plate or 1/4 the mass of a swing check disc.Plate weight has no impact on flow. F (Friction of Hinge) * 4.psd Home WEIGHS ABOUT 1/5 TH OF SWING CHECK AND HAS SHORT FACE TO FACE WIDTH. VOLUME& WEIGHT SAVES HANDLING EFFORTS. NO VALVE SUPPORTS REQD. INCLUDING THE ONE PROVIDED TO CONTAIN DAMAGES DUE TO SLAMMING. Dual Plate Check Valve Severe Service : Over 1,000,000 Cycles Dual Plate Check Valve Springs are normally designed for Average Service Conditions for Life of 100,000-1,000,000 Cycles to match life of valve. * Upside-down Installation DUAL PLATE CHECK VALVE More compact & structurally sound design. Same valve can be installed horizontally or vertically. Only Check Valve which can be installed for flow upside down due to spring assisted closure. Low pressure Drop & reduced Energy Loss irrespective of Pressure Ratings. Streamlined Flow-way Efficient & Positive sealing under most flow & pressure conditions. Valve closes before flow reversal, at zero velocity. Inherently Non-Slamming, No external devices / attachments required. Water Hammer almost non-existent SWING CHECK VALVE Large & difficult to analyse from stress concentration point in critical application due to intricate body shape. Suitable primarily for horizontal application. Not Possible Significant Pressure Loss & Energy Loss, which is still higher for higher pressure ratings. Swing restricted flow-way. Always require reverse flow for closure & back pressure for effective sealing. External attachments required to counteract slamming. Water Hammer tendency persists. * Compact, Light and Rugged Design Low Pressure Drop-thus, Lower Energy Loss. Total flexibility in installation - Horizontal to Vertical. Valve closure at zero velocity : Hence, ‘No valve- induced Water Hammer’. Inherently non-slamming design without any external fitments. Technically Superior always to Swing Check Valve including multi-door Swing Check Valve. An Economic Solution right through. * * -> Standard 1 1 1 1 DUAL PLATE CHECK 0.7 0.4 0.1 0.1 VALVE (Based on unit cost for swing check valve) Check Valve Economics Global Scene On Check Valves Swing Check Valves above 12”/16” generally need external Anti Slamming Device(s) making it further unwieldy and expensive - first cost & maintenance. After initial inertia of rethinking and limited sources of reliable suppliers in the past, the switchover from Mass Movement to Spring Actuation has taken place now. Improvement in availability and increasing competitiveness of Dual Plate Check Valves has changed the preference to Dual Plate Check Valves all over in process as well as in water management industries. Dual Plate Check Valves upto 12” are available even in ratings upto ANSI 2500 and API 5000 besides sizes upto 72” in lower ratings being most versatile design of Check Valve. * Global Trends Switch over to Wafer Check Valve (dual plate type ) is going on noticeably in Refineries , Petrochemicals and Process Industries besides general industries. Wherever Swing Check Valves are specified by process licensors and / or PMCs/EPCs as general specifications , switchover to Dual Plate Check Valves is generally welcome but not vice-versa. SWING CHECK VALVES ARE ON THEIR WAY OUT * Dual Plate Check Valve Crack Opening USE DUAL PLATE CHECK VALVES FOR ADVANTAGE TO ALL SAVE MONEY, EFFORTS & PROBLEMS Why not ? Gas , Air & Liquid application. Dual Plate Check Valves are Zero Velocity Non Slam Valves Water Supply Manual, published by Central Govt. has recommended use of Dual Plate Check Valves to prevent Water Hammer in Pipe Lines Indian Institute of Science, Bangalore has recommended for use of these valves in Pump houses, Rising mains and at intermediate locations along main lines Zero Velocity Valves Home Dual Plate Check Valves are an economical & technically superior alternative to Multi Door and Dash Pot Fitted Swing Check Valves any where and every where. Dual Plate Check Valve has been incorporated as separate equipment in the Surge Analysis Software package developed by Indian Institute of Science Bangalore. Dual Plate Check Valves Home To meet the requirement of Oil and Chemical Industry to pump fluids having high viscosity at ambient temperature like Ashes, bitumen, tar etc. To pump liquids with low vapourising temperature or highly volatile liquids. Jacketed Helps maintain temperature of flowing fluids through pipes. Prevents change of phase of highly volatile fluids and fluids with high solidification temperature. Contra circulating flow through the jackets ensures uniform dissipation of heat through radiation. Jacketed applications especially blower applications flow velocity is extremely low For Low Velocity Pipe Line Applications Dual Plate Check Valves For Systems Cross Country Pipe Lines Large Water Intake in Thermal Plants Large Size Home DPCV in various sizes for application in high Vacuum has been supplied to major clients in India Test facility for Vacuum Test at high temperature catering to all sizes valves are available. For example 750 mm (30”) SS 304 valves -12 Nos besides other small sizes supplied to OCFL, Paradeep Port. Vacuum Service Home Facility has been established for testing of valves using inert gas like Nitrogen at rated pressures as an alternative to Helium Leak Test. These test procedures were witnessed and approved by Engineers India Limited. Valves For Explosive Fluids 142 A & B, Noida Special Economic Zone, NOIDA - 201 305 (INDIA)