Glossary of Valve Terms and Acronyms
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VM‐GLOSSARY/WP White Paper Glossary of Valve Terms and Acronyms Table of Contents Glossary. 2 Acronyms . 21 Val‐Matic Valve & Mfg. Corp. • www.valmatic.com • [email protected] • PH: 630‐941‐7600 Copyright © 2019 Val‐Matic Valve & Mfg. Corp. Glossary of Valve Terms and Acronyms bonnet (to avoid under certain operating conditions, A that the stem could accidentally blow out). ANTI‐SLAM DEVICE: Device used on Air/Vacuum ACCUMULATOR TANK: Enclosed volume that valves to regulate the valve's closure and prevent contains a compressible fluid (gas) to provide standby the valve from being slammed closed during critical energy in the event of loss of system pressure. operation. Sometimes referred to as a slow closing ACCUMULATOR, HYDRAULIC: A pressure storage device, surge check valve or regulated exhaust reservoir in which a non‐compressible hydraulic fluid device. is held under pressure to provide standby energy in ANTI‐STATIC DEVICE: A spring‐loaded component of the event of loss of system pressure. a pipeline ball valve which provides contact between ACTUATOR: Mechanical, hydraulic, electric or stem and ball, and stem and body to eliminate static pneumatic device or mechanism used to open, electricity. position, or close a valve. APl: American Petroleum Institute‐organization AIR BOUND: Obstructed, as to the free flow of water, that develops standards for materials and articles because of air entrapped in a high point; used to used in the petroleum and gas gathering describe a pipeline or pump in such condition. (production) industry, and also the hydrocarbon‐ AIR RELEASE VALVE: A hydro‐mechanical valve processing industry. designed to slowly vent/release air automatically and ASME: American Society of Mechanical Engineers continuously from liquid piping systems. ‐ organization responsible for maintaining several AIR VALVE: Generic name used to describe a family of codes and large numbers of standards, covering valves used to control the release and admittance of numerous different industries. air to a pipeline or liquid handling system. Common ASSE: American Society of Sanitary Engineering – names for specific types include Air Release, organization responsible for certifying plumbing and Air/Vacuum and Combination. mechanical products and is also a third‐party certifier AIR VENT: An opening in a penstock or other for professionals in the plumbing and mechanical pipeline, covered tank, or well, that allows inflow industries. or outflow of air. ASTM: American Society for Testing and Materials‐ AIR/VACUUM VALVE: A float operated valve designed organization responsible for maintaining standards to exhaust large volumes of air upon pump start up and covering materials, testing methods, and in some provide vacuum protection by admitting large cases such as plastics, the dimensional and volumes of air upon pump shut down or if a column manufacturing standards for finished products. separation occurs. ATMOSPHERIC PRESSURE: External pressure exerted ALLOY STEEL: A steel consisting primarily of iron with on a body by the atmosphere: 1.0 Bar (14.7 psia) at some percentage of one or more other elements such sea level. as chromium, nickel, manganese, or vanadium AUSTENITIC STAINLESS STEEL: A common stainless deliberately added to enhance its properties. steel, where the primary microstructure is austenite ALTITUDE‐CONTROL VALVE: A valve that and the composition primarily iron but also includes automatically shuts off flow when the water level in both chromium and nickel. The steels are designated an elevated tank reaches a predetermined as 300 series such as 304, 316, CF8M, etc. elevation and opens when the pressure on the AWWA: American Water Works Association, Inc. – system side is less than that on the tank side. organization responsible for maintaining standards AMBIENT TEMPERATURE: Prevailing temperature of related to water treatment and water and the environment immediately surrounding an object. wastewater treatment products. ANSl: American National Standards Institute‐ standard development organization responsible for coordinating the work of U.S. standards writing B groups with each other and with other national standards organizations. Known as ASA until 1967. BACKFLOW ACTUATOR: Optional accessory for the ANTI‐BLOWOUT STEM: A valve stem that is made Swing‐Flex® Check Valve. Provided for opening and with a shoulder, positively retained by the body or holding open the valve disc to allow backflow 2 Glossary of Valve Terms and Acronyms through the line. Used to backwash a line, drain a outlet port, is blocked, while another small port is system or fill a wet well. provided for the purpose of bleeding down (draining BACK PRESSURE: The pressure exerted on the or depressurizing) the cavity in between. downstream side of a valve. BLOW DOWN VALVE (BDV): A small ball valve that is BACK SEAT: A shoulder on the stem of a gate or globe installed to vent body cavity pressure. valve which seals against a mating surface inside the BLOWOFF VALVE: A valve installed in a low point bonnet to prevent leakage of media through the bonnet or depression on a pipeline to allow drainage of the stuffing box when the valve is fully open. line. Also called washout valve. BACKFLOW PREVENTER: Any mechanical device, BODY: The principle pressure containing shell of a whether used singly or in combination with other valve or fitting. controls, designed to automatically prevent an BOLTED CONSTRUCTION: Describes a valve unintentional reversal or flow in a potable water construction in which the pressure shell elements distribution system. (such as body and closures of a trunnion ball valve) are BACKFLOW: The reversal of flow from that normally bolted together and so can be taken apart and repaired intended. in the field. BACKWASHING: The act of flowing clean water BONNET: The cover or removable top component of backwards through a valve or filter for the purpose a valve, containing the packing gland and stem of cleaning. opening. Generally, gate and globe valves are BALL VALVE: A valve that has a spherical, or section considered to have a bonnet. of a spherical, closure element that opens and BRONZE: An alloy of copper and tin. For special closes by rotating one‐quarter turn. purposes other metals such phosphorus, lead, zinc, BARE‐SHAFT (STEM): A valve supplied without lever silicon or aluminum are added. Most bronze alloys or hand wheel, where the end of the stem (shaft) is resist corrosion. exposed and ready for others to install their own BSI: British Standards Institution‐organization actuator.- responsible for standards in Great Britain and BEARING: A cylindrical machine located in the body Northern Ireland. hubs that is used to radially support the valve BUBBLE‐TIGHT: A seat leakage condition in which, shaft(s). during the allotted time of the test, no perceptible BELLEVILLE SPRING or BELLEVILLE WASHER: A disc‐ leakage comes past the seat being tested. Applies shaped washer, which provides axial spring force to air‐under‐water testing‐the same test using along its own centerline. water‐under‐air is referred to as drop tight. BERNOULLI'S LAW: A physical law of hydraulics that BUNA‐N: Common term for nitrile rubber. states that under conditions of uniform steady flow BUSHING: A lining or sleeve of metal or other material of water in a conduit or stream channel, the sum of inserted into a hole to limits its size, resist wear, or act the velocity head, pressure head, and head due to as a guide. elevation at any given point along such conduit or BUTT WELD: Weld where the adjoining edges to be channel is equal to the sum of these heads at any welded are parallel and facing each other. other point along such conduit or channel plus or BUTTERFLY VALVE: A valve that has a circular disc‐ minus the losses in head between the two points shaped closure element that pivots one‐quarter due to friction. tum about its vertical centerline to open and close. BEVEL GEAR ACTUATOR: Device facilitating operation BYPASS: A smaller line containing a valve that comes of a gate or globe valve by means of a set of bevel gears off a larger line just upstream of a major valve and having the axis of the pinion gear at right angles to that rejoins the same line just downstream of the valve. of the larger ring gear. BHN: Brinell Hardness Number ‐ a dimensionless indicator of material hardness. C BI‐DIRECTIONAL: A shut off valve capable of sealing in both direct and reverse pressure. CAST IRON: The common term for cast gray iron or iron BLOCK AND BLEED: A valve configuration in which the containing flake carbon in the range of 1.0 to 1.5 %. Cast flow through the valve, from the inlet port to the iron is brittle, exhibiting very little ductility before fracturing. 3 Glossary of Valve Terms and Acronyms CASTING: A product or the act of producing a product COLD WORKING PRESSURE (CWP): The maximum made by pouring molten metal into a mold and allowing allowable pressure under non‐shock conditions at it to solidify, thus taking the shape of the mold. ambient temperature, typically 125°F (52°C). CAVITATION: The phenomenon in which the local COLUMN SEPARATION: Phenomena which occurs pressure at a point in a flowing fluid becomes lower when a column of water in a pipeline separates than the vapor pressure of the fluid, thus causing creating a vacuum. small bubbles to form. The bubbles then implode COMBINATION AIR VALVE: Air Valve which when the local pressure rises again, causing shock combines the function of an Air Release valve with waves that are very destructive to the walls of the that of an Air/Vacuum valve. Available in both passageway or the valve trim in the area of the single body and dual body configurations. cavitation. COMPANION FLANGE: A pipe flange threaded CENTRIFUGAL PUMP: A pump consisting of an internally to receive a pipe length and drilled so it may impeller fixed on a rotating shaft and enclosed in a be bolted to another like flanges.