Check Valves Qatar Oil Gas: Complete API 6D & LNG Industry Guide Backflow in a compressor discharge line, LNG transfer system or refinery process unit is not a small process upset. It can destroy rotating equipment, affect process safety, and can even result in a complete unit shutdown in the worst of circumstances. Choosing the right type, material, and certification for check valves for sourcing in check valve Qatar oil gas is a line of defense for all procurement engineers, EPC contractors, and project teams that depend on check valves. The gas industry in Qatar is poised for major growth. The North Field Expansion project by Qatar Energy will expand Qatar's LNG output from 77 million tonnes per annum to 126 million tonnes per annum, which is creating sustained procurement demand for certified flow control equipment throughout Ras Laffan, Mesaieed and across the entire Qatari industrial base. In that demand, check valves are one of the most common items on any material requisition for a project. It is designed for high-level technical buyers who are familiar with basic valve fundamentals and are looking for a comprehensive approach for sourcing check valves for projects in the oil gas industry in Qatar: valve types, the true standards for compliance, material selection for sour service and seawater exposure, application guidance in LNG, offshore and refinery contexts, and a procurement checklist that distinguishes genuine certification from a logo on the catalogue page. Need reliable check valves for your Qatar oil, gas, or water project? Get a Quote from our team today. What Are Check Valves A check valve is a valve which opens and closes automatically, without the need of manual action or external power source, so that fluid can only flow through in one direction. The valve opens when flow is moving forward and then either closes automatically due to flow reversal (gravity, spring force, or both) or closes automatically once the pressure of the flow reverses, preventing backflow damage to upstream equipment like pumps, compressors, and process vessels. This guide on check valves is part of a broader category overview, found in our guide to industrial valves, that gives a full picture of the contribution check valves make to industrial piping system design, and how they can be used in conjunction with gate, globe and ball valves. Our comparison of gate valves and globe valves explains the difference between the engineering types of valves often used as part of the same piping system, in addition to check valves, when specifying for flow regulation versus simple non-return protection. How Check Valves Work UP pressure on the valve disc, swing plate or piston is greater than the valve's cracking pressure (the minimum UP pressure needed to lift the valve disc away from its seat) and the valve opens to allow flow. The closing element repels to its seat when flow is reduced or reversed due to spring force, gravity or both, and prevents any significant backflow volume from passing through the line. Check valves are required in those situations where there is a potential for reverse flow: compressor discharge lines, pump outlets, and any part of a pipeline where downstream pressure may exceed upstream pressure during upset conditions, since they are self operating. Types of Check Valves The right configuration is the basis of any decision on sourcing oil and gas check valves in Qatar, as each of the designs comes with its own set of pressure drop, installation orientation, and maintenance features. Check Valve Type Comparison Valve Type Closing Mechanism Typical Size Range Best Application Swing Check Valve Hinged disc swings closed under reverse flow 2" - 48" General pipeline, refinery process lines Dual Plate Check Valve Two spring-loaded plates, compact wafer body 2" - 48" Offshore platforms, space-constrained piping Piston Check Valve Spring-loaded piston, dampened closure 1/2" - 24" High-cycle service, pump discharge protection Cryogenic Check Valve Extended bonnet, low-temp rated trim 1/2" - 24" LNG transfer, liquefaction process lines Wafer Check Valve Compact dual or single plate, flangeless 2" - 36" Petrochemical plants, space-limited installations Swing Check Valves Extensive usage of a hinged disc that will open on forward flow and close on reverse flow or gravity is found in a swing check valve qatar refinery and pipeline projects. Swing checks are universally specified for general pipeline and refinery process line service over a wide range of pressure classes because the mechanical design is easy to manufacture, the full-bore flow path is simple, and the pressure drop is relatively low. Dual Plate Check Valves A dual plate check valve is qatar offshore platforms preferred that features two spring-loaded half-discs, positioned on a central pin and closing quickly and symmetrically as the flow slows down. The compact wafer-style body can be installed with significantly less length and weight than …