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Wyniki wyszukiwania dla: VALVE
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Outboard valve material testing
PublikacjaWykonano analizę przyczyn uszkodzenia korozyjnego zaworu zaburtowego. Sformułowano wnioski.
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JOURNAL OF HEART VALVE DISEASE
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Numerical Simulations for Transonic Flow in Control Valve
PublikacjaResults of numerical simulations for transonic flow in control valve are presented. The valve is the main part of an adaptive pneumatic shock absorber. Flow structure in the valve domain and the influence of the flow non-uniformity in the valve on a mass flow rate is investigated. Numerical simulation results are compared with experimental data.
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CFD Simulations and Tests of a Prototype Flow Control Valve
PublikacjaIn this paper a prototype of a flow control valve is described and numerically simulated. The flow control valve is used in hydraulic systems to maintain constant fluid flow despite changing loads of a receiver. The standard construction of this type of valves is modified mainly by eliminating the spring. The prototype consists the hydrostatically unloaded throttle valve and pressure ratio valve substituting pressure difference...
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Effect of Simultaneous Valve Closures in Hydraulic Piping Systems
PublikacjaThe paper investigates wave interference (between pressure waves) occurring in simple hydraulic systems. Water hammer was induced by simultaneous closure of three valves located at the reservoirs of a “Y” type hydraulic system. Numerical simulations were carried out with the help of the freeware computer package Allievi enabling the reader to replicate results in a direct manner. The influence of the following quantities has been...
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Failure analysis of the exhaust valve face in diesel marine engine
PublikacjaThe exhaust valve from marine diesel engine which was damaged after 2000 hours of service was investigated. In order to prolong the service time the valve face was cladded with cobalt base alloy using laser technique. After failure microstructural and chemical analyses reviled that cladding process was conducted improperly. The chemical composition of the clad layer was far from the designed one and what more completely inhomogeneous....
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Behavior of the exhaust valve cladding face under the service conditions
PublikacjaPodczas eksploatacji silnika okrętowego kluczowym problemem jest trwałośc zaworów wylotowych a w szczególności wąskiego fragmentu - przylgni grzybka zaworu, która decyduje o szczelności zaworu.Przylgnia wykonana przez laserowe napawanie stopu kobaltu została poddana badaniom w warunkach normalnej eksploatacji silnika L22 przez 2 lata. W tym czasi silnik był zasilany zarówno paliwem lekkim jak i biopaliwem. Po zdemontowaniu głowicy...
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Numerical Model of the Aortic Valve Implanted Within Real Human Aorta
PublikacjaCardiovascular system diseases are the main cause of deaths in developed and developing countries. The main reasons are myocardial infarction, heart failure, stroke and valvular diseases. These are caused mainly by arteriosclerosis. The valvular diseases involve a significant burden for the health care system and their frequency is rising with the patient age. This work describes the tools and numerical models appropriate for modeling...
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Study of structures and properties of the laser cladding exhaust valve after service
PublikacjaPrzylgnie zaworów wydechowych silnie obciążonego silnika okrętowego zostały pokryte warstwą wykonana ze stopu kobaltu za pomocą techniki napawania laserowego. Tak przygotowane zawory były eksploatowane przez 3000 godzin w silniku Daru Młodzieży. Po tym czasie zostały zdemontowane i poddane szczegółowej analizie. Warunki pracy spowodowały powstanie na powierzchni przylgni warstwy tlenków o różnej grubości, wykazującej skłonność...
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Fluid–Structure Interaction methods for the progressive anatomical and artificial aortic valve stenosis
PublikacjaCardiovascular system diseases, as aortic valve stenosis, are the main cause of mortality and morbidity among patients. There is still a room for enhancement of the diagnostic and therapeutic procedures, which will lead to improvement of the treatment. One of the remedies are the computer tools to support the medical diagnoses and prostheses design. The development of a procedure for modeling the aortic valves: anatomical tricuspid...
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Slowly-closing valve behaviour during steam machine accelerated start-up
PublikacjaThe paper discusses the state of stress in a slowly-closing valve during accelerated start-up of a steam turbine. The valve is one of the first components affected by high temperature gradients and is a key element on which the power, efficiency and safety of the steam system depend. The authors calibrated the valve model based on experimental data and then performed extended Thermal-FSI analyses relative to experiment. The issue...
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OPERATION OF TWO-SHAFT GAS TURBINE IN THE RANGE OF OPEN ANTI-SURGE VALVE
PublikacjaThis paper presents experimental tests of full-scale two-shaft gas turbine in the range of open anti-surge valve (ASV). The tests were carried out in a laboratory gas- turbine test stand belonging to Department of Automation and Power Engineering , Faculty of Ocean Engineering and Ship Technology , Gdańsk University of Technology. The tests covered the start-up and low load operation of the turbine set in the range of open...
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Multiscale model for blood flow after a bileaflet artificial aortic valve implantation
PublikacjaCardiovascular diseases are the leading cause of mortality in the world, mainly due to atherosclerosis and its consequences. The article presents the numerical model of the blood flow through artificial aortic valve. The overset mesh approach was applied to simulate the valve leaflets motion and to realize the moving mesh, in the aortic arch and the main branches of cardiovascular system. To capture the cardiac system’s response...
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The Impact of Material Selection on Durability of Exhaust Valve Faces of a Ship Engine – A Case Study
Publikacjawo alloys were used in order to extend the service life of marine engine exhaust valve head. Layers of cobalt base alloys were made of the powders with with chemical composition as follow: the layer marked L12; C-1,55%; Si-1,21%; Cr-29,7%; W-9%; Ni-2%; Mo<0,01%; Fe-1,7%; Co-54,83% and the layer marked N; C-1,45%; Co-38,9%; Cr-24,13%; Ni-10,43%; W-8,75%; Fe-7,64%; Mo-7,56%; Si-2,59%. Base metal was valve steel after heat treatment....
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Initial Investigation of Wave Interactions During Simultaneous Valve Closures in Hydraulic Piping Systems
PublikacjaThe effects of interference of pressure waves in simple piping systems were studied. A freeware computer code Allievi developed at the University of Valencia was used to simulate dynamic waveforms in simple and complex networks. The tests were carried out according to three scenarios. No pressure increases significantly exceeding the Joukowsky pressure in simple cases were noticed. When the effects of the simultaneous closing of...
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General anaesthesia or sedation for percutaneous aortic valve implantation? The questionnaire results and authors’ experience
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Late subclinical hemolysis and long-term outcomes after aortic valve replacement with On-X mechanical prostheses – a preliminary single-center report
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Effect of the ex situ physical and in situ chemical modification of bacterial nanocellulose on mechanical properties in the context of its potential applications in heart valve design
PublikacjaBacterial nanocellulose (BNC) is a promising material for heart valve prostheses. However, its low strength properties limit its applicability in cardiovascular surgery. To overcome these limitations, the mechanical properties of BNC can be improved through modifications. The aim of the research was to investigate the extent to which the mechanical properties of BNC can be altered by modifying its structure during its production...
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Gas corrosion influence on the exhaust valve face of the marine engine = Wpływ korozji gazowej na stan przylgni zaworów wylotowych silnika okrętowego
PublikacjaIstotnym czynnikiem wpływającym na poprawność funkcjonowania silnika okrętowego jest szczelność zaworów. Szczególnie w odniesieniu do zaworów wylotowych brak szczelności prowadzi do pogorszenie warunków spalania a przede wszystkim do przyspieszonego zniszczenia zawory poprzez uszkodzenia przylgni.Przylgnia grzybka zaworowego współpracuje z przylgnią gniazda zaworowego tworząc cykliczny szczelny kontakt stykowy w trakcie pracy silnika....
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The resistance investigation of the marine engine exchaust valve using the modelling chamber = Badania odporności zaworów wylotowych silnika okrętowego w komorze modelowej
PublikacjaWe współczesnej technice szereg części urządzeń i instalacji pracuje w długich okresach czasu i w złożonych warunkach obciążenia mechanicznego, termicznego i chemicznego. Próby wprowadzenia nowych rozwiązań technicznych muszą być poprzedzone szczegółowymi badaniami, które stwierdzą przydatność do konkretnych zastosowań. Problemem występującym w przemyśle okrętowym, a dokładniej w procesie eksploatacji silników okrętowych jest trwałość...
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Long-term mortality after transcatheter aortic valve implantation for aortic stenosis in immunosuppression-treated patients: a propensity-matched multicentre retrospective registry-based analysis
PublikacjaIntroduction Data regarding patients with a previous medical record of immunosuppression treatment who have undergone transcatheter aortic valve implantation (TAVI) are limited and extremely inconclusive. Available studies are mostly short term observations; thus there is a lack of evidence on efficacy and safety of TAVI in this specific group of patients. Aim To compare the in-hospital and long-term outcomes between patients...
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Regeneration of marine engine valves using laser surfacing
PublikacjaThis article presents an analysis of the applicability of laser surfacing of the exhaust valve face of a marine diesel engine using cobalt-based powder. After preparation by machining, the selected valves were subjected to laser surfacing using a high-power ROFIN DL020 laser. The EuTroLoy 16012 powder was used in the surfacing process. One of the valves was cut and subjected to metallographic examination and hardness measurements,...
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Determination of flow properties of a serial connection of a pressure relief valve (C=6.2, b=0.38) and a silencer (C=1.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a pressure relief valve (C=3.3, b=0.40) and a silencer (C=3.0) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a pressure relief valve (C=6.4, b=0.45) and a silencer (C=7.0) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a directional control valve (C=2.0, b=0.11) and a silencer (C=3.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere, (2) pressure...
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Determination of flow properties of a serial connection of a directional control valve (C=2.4, b=0.26) and a silencer (C=1.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere, (2) pressure...
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Determination of flow properties of a serial connection of a pressure relief valve (C=4.4, b=0.42) and a silencer (C=1.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a pressure relief valve (C=5.3, b=0.38) and a silencer (C=3.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a pressure relief valve (C=7.3, b=0.49) and a silencer (C=6.8) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a pressure relief valve (C=6.2, b=0.38) and a silencer (C=3.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a pressure relief valve (C=5.3, b=0.38) and a silencer (C=6.8) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a pressure relief valve (C=3.3, b=0.40) and a silencer (C=1.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a directional control valve (C=5.7, b=0.32) and a silencer (C=6.8) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere, (2) pressure...
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Determination of flow properties of a serial connection of a pressure relief valve (C=6.4, b=0.45) and a silencer (C=6.8) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a directional control valve (C=5.5, b=0.37) and a silencer (C=6.8) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere, (2) pressure...
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Determination of flow properties of a serial connection of a pressure relief valve (C=6.2, b=0.38) and a silencer (C=3.0) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a directional control valve (C=5.5, b=0.37) and a silencer (C=3.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere, (2) pressure...
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Determination of flow properties of a serial connection of a pressure relief valve (C=5.3, b=0.38) and a silencer (C=7.0) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a directional control valve (C=5.7, b=0.32) and a silencer (C=1.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere, (2) pressure...
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Determination of flow properties of a serial connection of a directional control valve (C=2.1, b=0.14) and a silencer (C=1.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere, (2) pressure...
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Determination of flow properties of a serial connection of a pressure relief valve (C=4.4, b=0.42) and a silencer (C=6.8) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a pressure relief valve (C=6.2, b=0.38) and a silencer (C=7.0) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a directional control valve (C=5.7, b=0.32) and a silencer (C=3.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere, (2) pressure...
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Determination of flow properties of a serial connection of a directional control valve (C=2.0, b=0.11) and a silencer (C=6.8) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere, (2) pressure...
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Determination of flow properties of a serial connection of a pressure relief valve (C=3.3, b=0.40) and a silencer (C=3.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a pressure relief valve (C=3.3, b=0.40) and a silencer (C=6.8) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a directional control valve (C=2.8, b=0.25) and a silencer (C=6.8) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere, (2) pressure...
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Determination of flow properties of a serial connection of a pressure relief valve (C=5.3, b=0.38) and a silencer (C=3.0) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient atmosphere, (2) pressure source...
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Determination of flow properties of a serial connection of a directional control valve (C=5.5, b=0.37) and a silencer (C=1.4) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a silencer arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere, (2) pressure...