AbstractPressure relief valve is one of the most important devices used on the security of pipelines, since it is responsible to guarantee the integrity of the installations. Generally, the response and behaviour of a relief valve during its transient is unknown by users, who employ simplified and static analysis to design the pipeline, further, the information provided by manufactures is limit...

Pressure relief valve is one of the most important devices used on the security of pipelines, since it is responsible to guarantee the integrity of the installations. Generally, the response and behavior of a relief valve during its transient is unknown by users, who employ simplified and static analysis to design the pipeline, further, the information provided by manufactures is limited. In th...

Traumatic CSDH enlarged in two cases with VP or LP shunt system although the shunt valve pressure was increased to 200 mmH2O. In surgery, the hematoma cavity pressure was found to be 130 and 140 mmH2O, suggesting that to raise the shunt valve pressure is not effective for decreasing CSDH volume.

In an investigation of the influence of glutaraldehyde fixation pressure and subsequent valve constraint on the coaptive characteristics of porcine aortic valves, 14 valves were examined, eight having been fixed at low pressure (congruent to 1 mm Hg) and six at high pressure (80 mm Hg). The coaptive ratios of the left and right coronary leaflets in the low-pressure-fixed valves showed a signifi...

The U.S. National Institute for Occupational Safety and Health (NIOSH) has been researching refuge alternatives (RAs) since 2007. RAs typically have built-in pressure relief valves (PRVs) to prevent the unit from reaching unsafe pressures. The U.S. Mine Safety and Health Administration requires that these valves vent the chamber at a maximum pressure of 1.25 kPa (0.18 psi, 5.0 in. H2O), or as s...

transcatheter aortic valve replacement (tavr) is a novel therapeutic intervention for the replacement of severely stenotic aortic valves in high-risk patients for standard surgical procedures. since the initial partner trial results, use of tavr has been on the rise each year. new delivery methods and different valves have been developed and modified in order to promote the minimally invasive p...

Conduits available for right ventricular outflow tract (RVOT) reconstruction eventually become stenotic and/or insufficient due to calcification. In order to reduce the incidence of reoperations we have developed and used a bicuspid valved polytetrafluoroethylene (PTFE) conduit for the RVOT reconstruction. The purpose of this study is to investigate the hemodynamic performance of the new design...

Industrial control valves often handle flows with very high pressure drops (conditions often referred to as severe service). In order to cope with such pressure drops, geometrically complex valve trims with many stages of pressure drops, are designed to prevent undesirable side effects such as cavitation etc. There are many different product designs for control valve trims produced by different...

We have developed a practical, low-cost ventricular assist device (VAD) comprising a newly designed blood chamber with a silicone lenticular sac and two silicone tri-leaflet valves (STV), made en bloc. This new VAD is seamless, can be made cost-effectively and assembled with the blood chamber and valve as one body. This novel design should reduce the incident of thrombus formation because of th...

The effect of chemical disinfection of the Heidbrink expiratory valve in buffered glutaraldehyde (Cidex solution) was investigated. Cidex caused stickiness and increased the opening pressure and resistance of the valve to different gas flow rates. An electrolytic type of corrosion may also have occurred. However, autoclaving of the Heidbrink valve did not appear to cause corrosion or significan...