The Adhesion Failure Mode in Stainless Steel Trim Spring-Operated Pressure Relief Valves

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Julia V. Bukowski ◽  
Robert E. Gross ◽  
William M. Goble
Keyword(s):  
Stainless Steel ◽  
Failure Mode ◽  
Failure Rate ◽  
Failure Modes ◽  
Service Failure ◽  
Failure Rates ◽  
Pressure Relief ◽  
Safety Integrity Level ◽  
Adhesion Failure ◽  
Pressure Relief Valves

This paper addresses dangerous failures of stainless steel (SS) trim spring-operated pressure relief valves (SOPRV) due to a particular failure mode (SS-to-SS adhesion), which is not currently being included in SOPRV failure rates. As a result, current methods for estimating or predicting failure rates for SS trim SOPRV significantly underestimate these failure rates and, consequently, overestimate the safety provided by the SOPRV as measured by its average probability of failure on demand (PFDavg) or its corresponding safety integrity level (SIL). The paper also illustrates the critical importance of root cause analysis (RCA) of dangerous SOPRV failures in understanding the impacts of various failure modes. Over 1300 proof test results for both new and used SS trim SOPRV from the Savannah River Site (SRS) were identified. RCA was used on the failed valves to classify those failed due to SS-to-SS adhesions. Statistical analysis of the data convincingly demonstrates adhesions, previously assumed to be only an in-storage failure phenomenon, are also an in-service failure mode, which needs to be included in SOPRV failure rates. The paper discusses the factors which potentially influence the adhesion failure mode, and suggests a possible approach to including this mode in failure rate predictions. An example illustrates how current failure rate models overestimate SS trim SOPRV safety by 1 or 2 orders of magnitude.

The Adhesion Failure Mode in Stainless Steel Trim Spring Operated Pressure Relief Valves

2012 ◽  
Author(s):  
Julia V. Bukowski ◽  
Robert E. Gross ◽  
William M. Goble
Keyword(s):  
Stainless Steel ◽  
Failure Mode ◽  
Failure Rate ◽  
Failure Modes ◽  
Service Failure ◽  
Failure Rates ◽  
Pressure Relief ◽  
Safety Integrity Level ◽  
Adhesion Failure ◽  
Pressure Relief Valves

This paper addresses dangerous failures of stainless steel (SS) trim spring operated pressure relief valves (SOPRV) due to a particular failure mode (SS-to-SS adhesion) which is not currently being included in SOPRV failure rates. As a result, current methods for estimating or predicting failure rates for SS trim SOPRV significantly underestimate these failure rates and, consequently, overestimate the safety provided by the SOPRV as measured by its average probability of failure on demand (PFDavg) or its corresponding safety integrity level (SIL). The paper also illustrates the critical importance of root cause analysis (RCA) of dangerous SOPRV failures in understanding the impacts of various failure modes. Over 1300 proof test results for both new and used SS trim SOPRV from the Savannah River Site (SRS) were identified. RCA was used on the failed valves to classify those failed due to SS-to-SS adhesions. Statistical analysis of the data convincingly demonstrates adhesions, previously assumed to be only an in-storage failure phenomenon, are also an in-service failure mode which needs to be included in SOPRV failure rates. The paper discusses the factors which potentially influence the adhesion failure mode and suggests a possible approach to including this mode in failure rate predictions. An example illustrates how current failure rate models overestimate SS trim SOPRV safety by one or two orders of magnitude.

A Four-Step Safety Integrity Level Analysis of Numerous Subsea Control System Components

2021 ◽  
Author(s):  
Jafar Mahmoudi
Keyword(s):  
Control System ◽  
Failure Mode ◽  
Failure Modes ◽  
Failure Rates ◽  
Safety Integrity Level ◽  
Closed Position ◽  
Failure Mode Classification ◽  
Time In Service ◽  
Level Analysis ◽  
Classification Table

Abstract In this paper, a four-step Safety Integrity Level (SIL) analysis is developed to analyze numerous components of the subsea control system based on the OREDA database. For this purpose, initially, a failure mode classification table is provided aiming to identify the number of dangerous as well as the prevalent failure modes. Then, several parameters such as the total time in service of the components are calculated. Also, failure rates are evaluated and the software checking is provided as the final step of the proposed framework. The results show that the number of dangerous failure modes is a noticeable value and the leakage in closed position is the failure mode occurring more than the other ones. Moreover, the quantification of parameters indicates that the process isolation valve of the subsea X-mass tree has the largest values in all the considered parameters. Besides, hydraulic coupling of the choke module and HC leak sensor are the two components with the highest value of failure rates.

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.

scholarly journals Perencanaan Perawatan Mesin Pump 107 Dengan Metode Reability Centered Maintenance (RCM) di PT. Petrokimia Gresik

2018 ◽  
Vol 1 (02) ◽  
pp. 33-38
Author(s):  
Rezza Wira Utomo
Keyword(s):  
Service Life ◽  
Failure Mode ◽  
Failure Rate ◽  
Failure Modes ◽  
Treatment Method ◽  
Maintenance Scheduling ◽  
Effect Analysis ◽  
Mean Time ◽  
Working Efficiency ◽  
Causes Of Failure

PT. Petrokimia Gresik is one of the largest fertilizer companies in Indonesia, locatedin Gresik, East Java. The pump 107 engine on the Ammonia unit is often damaged due to itslargest size compared to other types of pumps, as well as the result of carrying thick orconcentrated fluid (bluish black) so that it is heavy for the drainage process. The purpose ofthis study is to plan and recommend the proposed treatment method on the pump enginebased on the method used to improve the working efficiency of the pumping machine 107and determine the failure mode and diagnosis of the effects of failure modes that occur in thecomponent. The method used is the Reability Centered Maintenance (RCM) method whichis expected to be able to produce maintenance or maintenance scheduling that is increasinglydirected so that it can improve the performance and efficiency of the engine, reduce repaircosts, and extend the service life of the machine itself. From this study, the results are in theform of Faliure Model And Effect Analysis (FMEA), FMEA table preparation is carried outbased on component function data and maintenance reports which can then be determined byvarious failures resulting in malfunction. From the compilation of FMEA, it can be seenwhat the causes of failure are and what impacts they have caused. Next, the value of MeanTime Between Failure (MTBF) pump 107-JA is 15,829 hours, pump 107-JB is 43,764 hoursand pump 107-JCM is 19,578 hours. Maintainability M (t) or Mean Time to Repair (MTTR)value on pump 107-JA is 2,914 hours, pump 107-JB is 3,411 hours, and pump 107-JCM is3,1 hours, Availability A (t) value is pump 107-JA at 84.44%, pump 107-JB at 92.76% andpump 107-JCM at 86.31%. The last one is found that the failure rate of pump 107-JA is0.063172, pump 107-JB is 0.02284 and pump 107-JCM is 0.051.

The Effects of Maintenance Actions on the Average Probability of Failure on Demand of Spring Operated Pressure Relief Valves

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Julia V. Bukowski ◽  
William M. Goble ◽  
Robert E. Gross ◽  
Stephen P. Harris
Keyword(s):  
Probability Of Failure ◽  
Pressure Relief ◽  
Periodic Inspection ◽  
On Demand ◽  
Plant Safety ◽  
Safety Integrity Level ◽  
Proof Testing ◽  
Average Probability ◽  
Pressure Relief Valves ◽  
Inspection And Maintenance

The safety integrity level (SIL) of equipment used in safety instrumented functions is determined by the average probability of failure on demand (PFDavg) computed at the time of periodic inspection and maintenance, i.e., the time of proof testing. The computation of PFDavg is generally based solely on predictions or estimates of the assumed constant failure rate of the equipment. However, PFDavg is also affected by maintenance actions (or lack thereof) taken by the end user. This paper shows how maintenance actions can affect the PFDavg of spring operated pressure relief valves (SOPRV) and how these maintenance actions may be accounted for in the computation of the PFDavg metric. The method provides a means for quantifying the effects of changes in maintenance practices and shows how these changes impact plant safety.

Link Between Function-Flow Failure Rates and Failure Modes for Early Design Stage Reliability Analysis

2011 ◽  
Author(s):  
Bryan M. O’Halloran ◽  
Robert B. Stone ◽  
Irem Y. Tumer
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Design Method ◽  
Design Stage ◽  
Failure Rates ◽  
High Likelihood ◽  
Functional Failure ◽  
Early Design Stage ◽  
Flow Failure ◽  
Rate Design

This scope of this paper is to provide an extension to the Function Failure Design Method (FFDM). We first implement a more robust knowledge base using Failure Mode/Mechanism Distributions 1997 (FMD-97). Then failure rates from Nonelectric Parts Reliability Data (NPRD-95) are added to more effectively determine the likelihood that a failure mode will occur. The proposed Functional Failure Rate Design Method (FFRDM) uses functional inputs to effectively offer recommendations to mitigate failure modes that have a high likelihood of occurrence. This work uses a past example where FFDM and Failure Modes and Effects Analysis (FMEA) were compared to show that improvements have been made. A four step process is presented to show how the FFRDM is used during conceptual design.

scholarly journals Availability and LCOE Analysis Considering Failure Rate and Downtime for Onshore Wind Turbines in Japan

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3528
Author(s):  
Yuka Kikuchi ◽  
Takeshi Ishihara
Keyword(s):  
Failure Mode ◽  
Failure Rate ◽  
Wind Turbines ◽  
Failure Modes ◽  
Probability Distributions ◽  
Occurrence Rate ◽  
Baseline Scenario ◽  
Repair Cost ◽  
Effect Analysis ◽  
Onshore Wind

In this study, the availability and the levelized cost of energy (LCOE) are investigated considering failure rate and downtime for onshore wind turbines in Japan. The failure mode effect analysis is conducted using the wind turbine failure database collected by the New Energy and Industrial Technology Department Organization (NEDO). The normalized failure rate and downtime between Europe and Japan are comparable. The occurrence rate is similar between Europe and Japan, but the downtime in Japan is much longer than that of Europe. Three cost-reduction scenarios are then proposed to improve availability and to reduce LCOE using assumed failure rate and downtime in each mode based on the industry interview and best practices in Japan. The availability is improved from 87.4% for the baseline scenario to 92.7%, 95.5% and 96.4% for the three scenarios, and LCOE is also reduced from 13.7 Yen/kWh to 11.9, 11.0 and 10.7 Yen/kWh. Finally, the probability distributions of downtime and repair cost are obtained for each failure mode. It is found that the probability distributions of the failure modes with the shortest downtime show similar probability distributions regardless of the size of the assembly. The effects of downtime and repair-cost uncertainties on LCOE are also evaluated.

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

2014 ◽  
Vol 136 (6) ◽  
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 disk 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 less than or equal to 1 in. and set pressures less than 150 pounds per square inch gauge (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.

scholarly journals The Effects of Maintenance Actions on the PFDavg of Spring Operated Pressure Relief Valves

2014 ◽  
Author(s):  
Julia V. Bukowski ◽  
William M. Goble ◽  
Robert E. Gross ◽  
Stephen P. Harris
Keyword(s):  
End User ◽  
Pressure Relief ◽  
Periodic Inspection ◽  
On Demand ◽  
Plant Safety ◽  
Safety Integrity Level ◽  
Proof Testing ◽  
Average Probability ◽  
Pressure Relief Valves ◽  
Inspection And Maintenance

The safety integrity level (SIL) of equipment used in safety instrumented functions is determined by the average probability of failure on demand (PFDavg) computed at the time of periodic inspection and maintenance, i.e., the time of proof testing. The computation of PFDavg is generally based solely on predictions or estimates of the assumed constant failure rate of the equipment. However, PFDavg is also affected by maintenance actions (or lack thereof) taken by the end user. This paper shows how maintenance actions can affect the PFDavg of spring operated pressure relief valves (SOPRV) and how these maintenance actions may be accounted for in the computation of the PFDavg metric. The method provides a means for quantifying the effects of changes in maintenance practices and shows how these changes impact plant safety.

scholarly journals Risk Assessment of Express Delivery Service Failures in China: An Improved Failure Mode and Effects Analysis Approach

2021 ◽  
Vol 16 (6) ◽  
pp. 2490-2514
Author(s):  
Hongmei Shan ◽  
Qiaoqiao Tong ◽  
Jing Shi ◽  
Qian Zhang
Keyword(s):  
Risk Assessment ◽  
Failure Mode ◽  
Failure Modes ◽  
Service Failure ◽  
Cloud Model ◽  
Topsis Method ◽  
Delivery Service ◽  
Service Failures ◽  
Uncertainty Environment ◽  
Express Delivery

With the rapid growth of express delivery industry, service failure has become an increasingly pressing issue. However, there is a lack of research on express service failure risk assessment within the Failure Mode and Effects Analysis (FMEA) framework. To address the research gap, we propose an improved FMEA approach based on integrating the uncertainty reasoning cloud model and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method. The cloud model describing randomness and fuzziness in uncertainty environment is adopted to achieve the transformation between the qualitative semantic evaluation of occurrence (O), severity (S), and detection (D) risk factors of FMEA and the quantitative instantiation and set up the comprehensive cloud of risk assessment matrix for express delivery service failure (EDSF). The TOPSIS method calculates and ranks the relative closeness coefficients of EDSF mode. Finally, the rationality and applicability of the proposed method are demonstrated by an empirical study for the express delivery service in China. It is found that among 18 express delivery service failure modes, six service failure modes with high risk are mainly located in the processing and delivery stages, while six service failures with the relatively low risk are involved in the picking-up and transportation stages. This study provides insight on how to explore the risk evaluation of express delivery service failure, and it helps express delivery firms to identify the key service failure points, develop the corresponding service remedy measures, reduce the loss from service failures, and improve the service quality.

Sign in / Sign up

Export Citation Format

Share Document