Specification for Angle Style, Pressure Relief Valves for Steam, Gas, and Liquid Services

2003 ◽  
Author(s):  
Keyword(s):  
Pressure Relief ◽  
Pressure Relief Valves

Dynamic Behavior of Transportation Pressure Relief Valves Under Simulated Fire Impingement Conditions

1999 ◽  
Vol 122 (1) ◽  
pp. 60-65 ◽  
Author(s):  
A. J. Pierorazio ◽  
A. M. Birk
Keyword(s):  
Dynamic Testing ◽  
Test Facility ◽  
Time Varying ◽  
Relief Valve ◽  
Pressure Relief ◽  
Flow Rates ◽  
Depth Analysis ◽  
Pressure Relief Valves ◽  
Accident Conditions ◽  
Insight Into

This paper presents the results of the first full test series of commercial pressure relief valves using the newly constructed Queen’s University/Transport Canada dynamic valve test facility (VTF) in Maitland, Ontario. This facility is unique among those reported in the literature in its ability to cycle the valves repeatedly and to measure the time-varying flow rates during operation. This dynamic testing provides much more insight into valve behavior than the single-pop or continuous flow tests commonly reported. The facility is additionally unique in its simulation of accident conditions as a means of measuring valve performance. Specimen valves for this series represent 20 each of three manufacturers’ design for a semi-internal 1-in. 312 psi LPG relief valve. The purpose of this paper is to present the procedure and results of these tests. No effort is made to perform in-depth analysis into the causes of the various behaviors, nor is any assessment made of the risk presented by any of the valves. [S0094-9930(00)01201-4]

scholarly journals Investigation of Adhesion Formation in New Stainless Steel Trim Spring Operated Pressure Relief Valves

2013 ◽  
Author(s):  
Julia V. Bukowski ◽  
Robert E. Gross ◽  
William M. Goble
Keyword(s):  
Stainless Steel ◽  
Test Data ◽  
Adhesion Formation ◽  
End Users ◽  
Excess Pressure ◽  
Pressure Relief ◽  
Significant Percentage ◽  
Pressure Relief Valves

Examination of proof test data for new (not previously installed) stainless steel (SS) trim spring operated pressure relief valves (SOPRV) reveals that adhesions form between the seat and disc in about 46% of all such SOPRV. The forces needed to overcome these adhesions can be sufficiently large to cause the SOPRV to fail its proof test (FPT) prior to installation. Furthermore, a significant percentage of SOPRV which are found to FPT are also found to “fail to open” (FTO) meaning they would not relief excess pressure in the event of an overpressure event. The cases where adhesions result in FTO or FPT appear to be confined to SOPRV with diameters ≤ 1 in and set pressures < 150 psig and the FTO are estimated to occur in 0.31% to 2.00% of this subpopulation of SS trim SOPRV. The reliability and safety implications of these finding for end-users who do not perform pre-installation testing of SOPRV are discussed.

Gas-Powered and Portable Ventilators: An Evaluation of Six Models

1992 ◽  
Vol 7 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Jerry P. Nolan ◽  
Peter J.F. Baskett
Keyword(s):  
Tidal Volume ◽  
Minute Ventilation ◽  
Pressure Gauge ◽  
Inspiratory Pressure ◽  
Pressure Relief ◽  
Patient Transport ◽  
Cardio Pulmonary Resuscitation ◽  
Air Mixing ◽  
Pressure Relief Valves ◽  
Manual Methods

AbstractIntroduction:Gas-powered resuscitators (ventilators) designed to be used primarily for resuscitation should be basic and simple to use. They offer many advantages over manual methods of ventilation during in-hospital cardiopulmonary resuscitation. Portable ventilators intended for critical care transport require additional, more sophisticated features such as: adjustable pressure limiting valves, air-mixing, airway pressure gauge, independent tidal volume and rate controls, and a Positive End-Expiratory Pressure (PEEP) valve. The performance of six gas-powered resuscitators/portable ventilators (TransPAC, Oxylog, Ambu Matic, ERA 2000, Uni-Vent, and MARS) was evaluated.Methods:The accuracy of volumes delivered to a test lung at three different compliance and resistance settings, was assessed for each ventilator prior to clinical evaluation during cardio-pulmonary resuscitation (CPR) and patient transport.Results:In each circumstance, measured tidal volumes and levels of minute ventilation decreased as resistance was increased and compliance reduced. Much of this loss of measured tidal volume occurred through inspiratory pressure relief valves that tended to start leaking at pressures below the preset level. Increasing levels of back-pressure resulted in further reductions in tidal volume when the ventilators were tested using the air-mix mode (available on three of the devices). In general, each resuscitator functioned well when used during CPR within the hospital.Conclusions:Each resuscitator tested failed to deliver the preset volumes and this must be considered during their use. Inspiratory pressure relief valves for all but one of the ventilators tested would not permit the delivery of adequate levels of ventilation in patients with low pulmonary compliance and/or high airway resistance.

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