Direct acting spring loaded pressure relief valve is one of the most important devices to ensure security to pipeline oil transport. However, relief valves’ manufactures generally only provide information on valve characteristics under full opening stage, which is obtained under steady state regime, therefore, valve and flow’s transient behavior are neglected. Understanding the transient behavi...

The study of the performance dynamic hydraulic throttling under condition stable fluid is great significance. effect a step change in pressure differences on valve studied. This paper studies and static hydraulic-valve-outlet throttling-speed regulation system, builds more accurate mathematical model, considers linear factors flow hydraulic-valve throttling, analyzes influence step-load differe...

bailon mitral valvuloplasty and closed mitral valve conunissurotomy were performed in 450 and 127 patients, respectively. also, 254 patients with severe mitral stenosis were enrolled in a prospective randomized trial comparing the two procedures. immediately after balloon mitral valvuloplasty, mean left atrial pressure was 11.38±3.54 mmhg, transmitral valve gradient was 1.8±2 mmhg, and mitral v...

BaIlon mitral valvuloplasty and closed mitral valve conunissurotomy were performed in 450 and 127 patients, respectively. Also, 254 patients with severe mitral stenosis were enrolled in a prospective randomized trial comparing the two procedures. Immediately after balloon mitral valvuloplasty, mean left atrial pressure was 11.38±3.54 mmHg, transmitral valve gradient was 1.8±2 mmHg, and mit...

PURPOSE To present a novel design of an implantable glaucoma valve based on ferrofluidic nanoparticles and to compare it with a well-established FDA approved valve. SETTING Massachusetts Eye & Ear Infirmary, Boston, USA. METHODS A glaucoma valve was designed using soft lithography techniques utilizing a water-immiscible magnetic fluid (ferrofluid) as a pressure-sensitive barrier to aqueous ...

A 7-year-old girl presented in semicomatose condition. She had received a ventriculoperitoneal shunt using a Codman-Hakim programmable valve. Head computed tomography demonstrated hydrocephalus and head radiography showed that the pressure setting of the shunt valve had changed to 60 mmH(2)O from 40 mmH(2)O. The pressure setting was returned to 40 mmH(2)O, and she was discharged because her cli...

Calcific Aortic Valve Disease: Where Are We Now? Calcific aortic valve disease (CAVD) is the most common valvular heart disease in the aging population of the developed world with projected disease burden expected to increase from 2.5 million in 2000 to 4.5 million in 2030. In CAVD, the leaflets become thick, stiff, scarred, and calcified, often covered with nodules on the surface facing the ao...

Calcific Aortic Valve Disease: Where Are We Now? Calcific aortic valve disease (CAVD) is the most common valvular heart disease in the aging population of the developed world with projected disease burden expected to increase from 2.5 million in 2000 to 4.5 million in 2030. In CAVD, the leaflets become thick, stiff, scarred, and calcified, often covered with nodules on the surface facing the ao...

The purpose of passive air blast safety valves is to protect people and technical installations in buildings or facilities. In case explosions, e.g. due failures an oil- gas refinery, the valve should close milliseconds with incident shock wave substantially reduce blast-pressure leakage into building. On other hand, exhibit a low pressure drop normal operation order power consumption ventilato...