281. An Evaluation of a Qualitative Fit-Test Agent (BITREX) to Detect Exhalation Valve Leakage in Full-Facepiece Respirators

2000 ◽  
Author(s):  
R. McKay ◽  
C. Rodriquez
Keyword(s):  
Test Agent ◽  
Valve Leakage ◽  
Exhalation Valve

Method Development for Measuring Respirator Exhalation Valve Leakage

1992 ◽  
Vol 7 (3) ◽  
pp. 174-179 ◽  
Author(s):  
Scott Brueck ◽  
Matti Lehtimaki ◽  
Usha Krishnan ◽  
Klaus Willeke
Keyword(s):  
Method Development ◽  
Valve Leakage ◽  
Exhalation Valve

Recent Patents on Valve Mechanism Device

2020 ◽  
Vol 13 (3) ◽  
pp. 230-241
Author(s):  
Ye Dai ◽  
Hui-Bing Zhang ◽  
Yun-Shan Qi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Flow Direction ◽  
Research Progress ◽  
Valve Mechanism ◽  
Advantages And Disadvantages ◽  
Valve Structure ◽  
Valve Leakage ◽  
Safety And Reliability

Background: Valves are an important part of nuclear power plants and are the control equipment used in nuclear power plants. It can change the cross-section of the passage and the flow direction of the medium and has the functions of diversion, cutoff, overflow, and the like. Due to the earthquake, the valve leaks, which will cause a major nuclear accident, endangering people's lives and safety. Objective: The purpose of this study is to synthesize the existing valve devices, summarize and analyze the advantages and disadvantages of various devices from many literatures and patents, and solve some problems of existing valves. Methods: This article summarizes various patents of nuclear-grade valve devices and recent research progress. From the valve structure device, transmission device, a detection device, and finally to the valve test, the advantages and disadvantages of the valve are comprehensively analyzed. Results: By summarizing the characteristics of a large number of valve devices, and analyzing some problems existing in the valves, the outlook for the research and design of nuclear power valves was made, and the planning of the national nuclear power strategic goals and energy security were planned. Conclusion: Valve damage can cause serious safety accidents. The most common is valve leakage. Therefore, the safety and reliability of valves must be taken seriously. By improving the transmission of the valve, the problems of complicated valve structure and high cost are solved.

scholarly journals Cytotoxicity of filtering respiratory protective devices from the waste sorting industry: A comparative study between interior layer and exhalation valve

2021 ◽  
Vol 155 ◽  
pp. 106603
Author(s):  
Carla Viegas ◽  
Magdalena Twarużek ◽  
Marta Dias ◽  
Beatriz Almeida ◽  
Elisabete Carolino ◽  
...  
Keyword(s):  
Comparative Study ◽  
Interior Layer ◽  
Protective Devices ◽  
Respiratory Protective Devices ◽  
Exhalation Valve

Complete Simulation and Fault Diagnosis of Sucker-Rod Pumping

2021 ◽  
pp. 1-14
Author(s):  
Bin Zhang ◽  
Xianwen Gao ◽  
Xiangyu Li
Keyword(s):  
Fault Diagnosis ◽  
Simulation Model ◽  
Oil Wells ◽  
Oil Field ◽  
Motor Power ◽  
Sucker Rod ◽  
Computer Aided ◽  
Valve Leakage ◽  
Information Construction ◽  
Diagnosis Model

Summary In this paper, we study the simulation and fault diagnosis of a conventional pumping unit under balanced conditions. As the energy input of sucker-rod pumping (SRP), the motor power contains abundant information about the whole pumping cycle under SRP. It is an important step in oilfield information construction to establish a computer-aided system that is based on motor power diagnosis. Hence, we propose an SRP simulation model for generating motor power. By analyzing the working conditions of six oil wells that contain normal or insufficient liquid supply, gas lock, traveling valve leakage, standing valve leakage, and parting rod, we simulate the motor power of the six wells. In addition, we verify the simulation model using a test well with favorable performance and establish the motor power template set (MPTS) using this simulation model. To allow for computer-aided diagnosis, we propose the use of the area proportion method to extract motor power features. We establish a diagnosis model of oilwell conditions that is based on oblique decision tree and train the diagnosis model using the MPTS. Through the verification of six oil wells in the actual production of the oil field, the diagnosis model shows a favorable response. The test results show that the methods of establishing MPTS and oilwell working-condition diagnosis are feasible.

Deep belief network-based internal valve leakage rate prediction approach

Measurement ◽  
2019 ◽  
Vol 133 ◽  
pp. 182-192 ◽  
Author(s):  
Shen-Bin Zhu ◽  
Zhen-Lin Li ◽  
Shi-Min Zhang ◽  
Ying-Yu ◽  
Hai-Feng Zhang
Keyword(s):  
Leakage Rate ◽  
Deep Belief Network ◽  
Belief Network ◽  
Rate Prediction ◽  
Valve Leakage ◽  
Prediction Approach

Numerical Simulation on the Sound Field of Gas Valve Due to Inner Leakage

2009 ◽  
Author(s):  
Bing Wang ◽  
Yadong Wang ◽  
Wenjun Liang ◽  
Shuiping Sheng ◽  
Jianping Guo ◽  
...  
Keyword(s):  
Complex Geometry ◽  
Sound Field ◽  
Needle Valve ◽  
Gas Leakage ◽  
Testing Method ◽  
Acoustic Equation ◽  
Valve Leakage ◽  
Acoustic Testing ◽  
Difference Time ◽  
Reynolds Average

Recently, acoustic testing method has been widely used for valve leakage inspection. Traditional method has difficulty carrying out research on the acoustic testing of valve leakage due to the complex geometry of the valve and the effect of flow on sound field. Thus, a numerical method was put forward based on Reynolds average N-S equation and k – ε equation in order to investigate the flow of the inner leakage of ball valve, needle valve and gate valve. Furthermore, difference time domain method was adopted to simulate the noise field of the flow based on Lighthill acoustic equation. And the characteristics of acoustic distribution were obtained. The results showed that turbulent flow was the main cause of jet noise inner the valve due to gas leakage. And the acoustic distribution had directivity. There were about 10 ∼ 25dB difference between the upstream and downstream of the leaking valve. The position with the highest sound pressure was also found out.

scholarly journals Study of Dispersion Hazard Potential of The LPG Stations Around the RDE Site in Rainy and Dry Season

2018 ◽  
Vol 20 (1) ◽  
pp. 17
Author(s):  
Siti Alimah ◽  
June Mellawati
Keyword(s):  
Wind Speed ◽  
Wind Direction ◽  
Power Reactor ◽  
Dry Season ◽  
Potential Hazard ◽  
Hazard Potential ◽  
Liquid Petroleum Gas ◽  
Atmospheric Data ◽  
Valve Leakage ◽  
Site Evaluation

STUDY OF DISPERSION HAZARD POTENTIAL OF THE LPG STATIONS AROUND THE RDE SITE IN RAINY AND DRY SEASON. There are two LPG station (SPPBE) which are the depot of filling, storage and distribution of  Liquid Petroleum Gas (LPG) namely PT. BM and PT. ISR which the distance each are 2,995 and 4,141 km from Experimental Power Reactor (RDE) site with capacity 15 and 30 tons. LPG station is a stationary source, which is one aspect of the external human induced events that need to be analyzed in the preparation of site evaluation reports to obtain site permits. Hazard potential that may occur from the depot LPG are fire, explosion and dispersion of hazardous and toxic gas. The release of LPG due to valve leakage which is then dispersed at a certain dose has potentially harmful to health, even death to the population around  the RDE site. The purpose of the study was to know the effect of seasons (rainy and dry) to the potential hazard of LPG dispersion from LPG truck tank valve to the around RDE site. The method of study are collection the atmospheric data such as wind direction and speed, temperature and humidity, collection the station LPG characteristic, such as mass of gas, diameter and length of tank, and valve diameter, etc. The atmospheric data was obtained from Pondok Betung Climatology Station, in dry, transition, and rainy seasons, furthermore data was analyzed using ALOHA software version 5.4.5. The results show dispersion from LPG release due to valve  leakage from PT. BM and PT. ISR around the RDE site, in the dry season (April), the transition (January and July) as well as the rainy season (October) does not hazardous to the RDE site. Maximum threat zone occurs in dry season at April (wind speed 1.54 m/s), which reaches radius 179 m with airborne LPG concentration 5500 ppm, radius 111 m with concentration 17000 ppm and radius 71 m with concentration 53000 ppm.

Sign in / Sign up

Export Citation Format

Share Document