Pressure Relief Devices in the 1974 Edition of Section VIII, Pressure Vessels

Appendix M of Section VIII, Division 1 of the ASME Boiler and Pressure Vessel Code[1] provides rules for the use of isolation (stop) valves between ASME Section VIII Division 1 pressure vessels and their protective pressure relieving device(s). These current rules limit stop valve applications to those that isolate the pressure relief valve for inspection and repair purposes only [M-5(a), M-6], and those systems in which the pressure originates exclusively from an outside source [M-5(b)]. The successful experience of the refining and petrochemical industries in the application and management of full area stop valves between pressure vessels and pressure relief devices suggested that the time was appropriate to review and consider updates to the current Code rules. Such updates would expand the scope of stop valve usage, along with appropriate safeguards to ensure that all pressure vessels are provided with overpressure protection while in operation. This white paper provides a summary of the current Code rules, describes the current practices of the refining and petrochemical industries, and provides an explanation and the technical bases for the Code revisions.

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The Effect of Reduced Design Margin on the Fire Survivability of ASME Code Propane Tanks

Journal of Pressure Vessel Technology ◽

10.1115/1.1845476 ◽

2005 ◽

Vol 127 (1) ◽

pp. 55-60

Author(s):

A. M. Birk

Keyword(s):

Wall Thickness ◽

Pressure Vessels ◽

Relief Valve ◽

Pressure Relief ◽

Asme Code ◽

Section Viii ◽

Failure Scenario ◽

Fill Level ◽

Relief System ◽

Design Margin

In the 1999 addenda to the 1998 ASME pressure vessel code, Section VIII, Div. 1 there was a change in design margin for unfired pressure vessels from 4.0 to 3.5. This has resulted in the manufacture of propane and LPG tanks with thinner walls. For example, the author has purchased some new 500 gallon ASME code propane tanks for testing purposes. These tanks had the wall thickness reduced from 7.7 mm in 2000 to 7.1 mm in 2002 and now to 6.5 mm in 2004. These changes were partly due to the code change and partly due to other factors such as steel plate availability. In any case, the changes in wall thickness significantly affects the fire survivability of these tanks. This paper presents both experimental and computational results that show the effect of wall thickness on tank survivability to fire impingement. The results show that for the same dank diameter, tank material, and pressure relief valve setting, the thinner wall tanks are more likely to fail in a given fire situation. In severe fires, the thinner walled tanks will fail earlier. An earlier failure usually means the tank will fail with a higher fill level, because the pressure relief system has had less time to vent material from the tank. A higher liquid fill level at failure also means more energy is in the tank and this means the failure will be more violent. The worst failure scenario is known as a boiling liquid expanding vapor explosion and this mode of failure is also more likely with the thinner walled tanks. The results of this work suggest that certain applications of pressure vessels such as propane transport and storage may require higher design margins than required by Section VIII ASME code.

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The Effect of Pressure Relief Valve Blowdown and Fire Conditions on the Thermo-Hydraulics Within a Pressure Vessel

Journal of Pressure Vessel Technology ◽

10.1115/1.2218353 ◽

2006 ◽

Vol 128 (3) ◽

pp. 467-475 ◽

Cited By ~ 1

Author(s):

A. M. Birk ◽

J. D. J. VanderSteen

Keyword(s):

Thermal Stratification ◽

Pressure Vessels ◽

Pressure Relief Valve ◽

Relief Valve ◽

Pressure Relief ◽

Pressure Transducers ◽

Hydrocarbon Pool ◽

Computer Controlled ◽

C 50 ◽

Fire Conditions

In the summers of 2000 and 2001, a series of controlled fire tests were conducted on horizontal 1890liter (500 US gallon) propane pressure vessels. The test vessels were instrumented with pressure transducers, liquid space, vapor space, and wall thermocouples, and an instrumented flow nozzle in place of a pressure relief valve (PRV). A computer controlled PRV was used to control pressure. The vessels were heated using high momentum, liquid propane utility torches. Open pool fires were not used for the testing because they are strongly affected by wind. These wind effects make it almost impossible to have repeatable test conditions. The fire conditions used were calibrated to give heat inputs similar to a luminous hydrocarbon pool fire with an effective blackbody temperature in the range of 850°C±50°C. PRV blowdown (i.e., blowdown=poppressure−reclosepressure) and fire conditions were varied in this test series while all other input parameters were held constant. The fire conditions were varied by changing the number of burners applied to the vessel wall areas wetted by liquid and vapor. It was found that the vessel content’s response and energy storage varied according to the fire conditions and the PRV operation. The location and quantity of the burners affected the thermal stratification within the liquid, and the liquid swelling (due to vapor generation in the liquid) at the liquid∕vapor interface. The blowdown of the PRV affected the average vessel pressure, average liquid temperature, and time to temperature destratification in the liquid. Large blowdown also delayed thermal rupture.

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Design Formulas of Blind End Closures for High Pressure Vessels

Journal of Pressure Vessel Technology ◽

10.1115/1.2967886 ◽

2009 ◽

Vol 131 (3) ◽

Author(s):

R. D. Dixon ◽

E. H. Perez

Keyword(s):

High Pressure ◽

Fatigue Life ◽

Maximum Stress ◽

Accurate Determination ◽

Pressure Vessels ◽

Stress Distributions ◽

Fatigue And Fracture ◽

Asme Code ◽

Section Viii

The available design formulas for flat heads and blind end closures in the ASME Code, Section VIII, Divisions 1 and 2 are based on bending theory and do not apply to the design of thick flat heads used in the design of high pressure vessels. This paper presents new design formulas for thickness requirements and determination of peak stresses and stress distributions for fatigue and fracture mechanics analyses in thick blind ends. The use of these proposed design formulas provide a more accurate determination of the required thickness and fatigue life of blind ends. The proposed design formulas are given in terms of the yield strength of the material and address the fatigue strength at the location of the maximum stress concentration factor. Introduction of these new formulas in a nonmandatory appendix of Section VIII, Division 3 is recommended after committee approval.

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Methods for Design of Explosion Containment Vessels

Volume 1: Codes and Standards ◽

10.1115/pvp2008-61732 ◽

2008 ◽

Author(s):

Yongjun Chen ◽

Jinyang Zheng ◽

Guide Deng ◽

Yuanyuan Ma ◽

Guoyou Sun

Keyword(s):

Time Use ◽

Design Method ◽

Failure Criteria ◽

Pressure Vessels ◽

Design Criterion ◽

Load Factor ◽

Multiple Use ◽

Strain Limit ◽

Section Viii ◽

Future Work

Explosion containment vessels (ECVs), which can be generally classified into three categories, i.e., multiple use ECVs and one-time use ECVs, single-layered ECVs and multi-layered ECVs, metallic ECVs and composite ECVs according to the usage, structural form and the bearing unit, respectively, are widely used to completely contain the effects of explosions. There are fundamental differences between statically-loaded pressure vessels and ECVs that operate under extremely fast loading conditions. Conventional pressure design codes, such as ASME Section VIII, EN13445 etc., can not be directly used to design ECVs. So far, a lot of investigations have been conducted to establish design method for ECVs. Several predominant effects involved in the design of ECVs such as scale effect, failure mode and failure criteria are extensively reviewed. For multiple use single-layered metallic ECVs, dynamic load factor method and AWE method are discussed. For multiple use composite ECVs, a minimum strain criteria based on explosion experiments is examined. For one-time use ECVs, a strain limit method proposed by LANL and a maximum strain criteria obtained by Russia are discussed for metallic vessel and composite vessel, respectively. Some improvements and possible future work in developing design criterion for ECVs are recommended as a conclusion.

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