Behind Closed Doors; Pipeline Closures and Traps Revisited

Pipeline doors or “closures” are commonplace in the pipeline industry, providing access to the pipeline as well as to high-pressure equipment associated with the pipeline such as filters, separators, strainers, etc. Despite their prevalence, the importance of closures to the safe and efficient operation of a pipeline system is often overlooked. Recent changes in closure definitions and terminology warrant a review of the systems, applicable standards, designs and considerations related to choosing a closure for a desired purpose. Closure can be defined differently, one definition, for example, is a pressure-containing component used to blind off an opening nozzle on a vessel or end of pipeline which could mean simply a bolted blind flange, a T-bolt cap. Others define a “quick-opening” closure as a pressure-containing component used for repeated access to the interior of a piping system. So clearly there are several ways the current codes can be interpreted, but what does it all mean? In addition to the changes in definitions and terminology on the closures, during the design of the traps, many different codes and standards may be applied. Both the product that will be transported and where the equipment will be located can impact on the materials and the design of the traps. This can include the transitions from one design code to another, commonly referred to as breaks in the specifications, or “spec breaks”. This paper will focus on quick-actuating and quick-opening closures, presenting a history of pipeline closures from the early development to recent innovations. Also, the paper will address the issue of spec breaks and how designers and owners can benefit from the right choices for safe, cost effective and code compliant launch and receive facilities.

Two deaths due to explosion of cylinders of liquid petroleum gas

Background Cylinder blasts can inflict multi-system life-threatening injuries to one or many persons simultaneously if they are nearby. The explosion in high-pressure equipment produces injuries due to its varied effects. Cases have been reported where the blast occurred in balloon gas cylinder, oxyacetylene gas cylinder, oxygen cylinder, coffee machine, and compressor of a split air conditioner (AC). Most of the cases are accidental. The investigation into the blast circumstances is of utmost importance to find out the manner and device involved. Case presentation Here, we present a report of two cases where victims suffered blast injuries at the same location due to the explosion of two different capacity liquefied petroleum gas (LPG) domestic cylinder and died on the spot. Conclusion The investigation into the blast circumstances is of utmost importance to find out the manner and device involved. Malpractice involving use of cylinder to fill another one might be dangerous for the person involved and present in the vicinity. This practice should be discouraged by lay person.

Revisiting the ASME Pressure-Viscosity Report Using the Tait-Doolittle Correlations

The ASME Pressure-Viscosity Report was a seminal publication on high pressure-viscosity and density supervised by the ASME Research Committee on Lubrication, sponsored by dozens of industries, and undertaken by Harvard University using high-pressure equipment developed by Prof. P. W. Bridgman. The resulting measurements of the “Viscosity and Density of Over 40 Lubricating Fluids of Known Composition at Pressures to 150,000 psi (1034 MPa) and Temperatures to 425 °F (218.3 °C/491.5 K)” should have become an invaluable reference to tribologists around the world. The present work revisits that monumental effort to distill the results into an established equation of state using modern computer software. The authors used curve-fitting techniques to fit measured density and viscosity data to the parameters of the Tait-Doolittle equation for use in further tribological modeling. This information will help a new generation of engineers to model the piezoviscous properties of lubricant base-stocks in diverse tribological applications.

Alternative Design Approach by Finite Element Analysis for High Pressure Equipment

Components that are subject to pressure, typical of the pressure vessel industry, can be designed using such calculation methods as “Design by Rule-DBF” or “Design by Analysis-DBA”. DBA, based on the FEM, is used increasingly often because, in addition to providing a reduction in thickness due to the lower uncertainty on the calculation, it helps to verify and study physical phenomena and complex geometry that are otherwise difficult to research while offering a more intuitive usability of the results. In this paper we wish to offer, in an educative and qualitative manner, a general overview of DBA from the creation of the model to obtaining the results, describing the types of analysis that can be carried out according to the constitutive model of the material used and the degree of accuracy that can be achieved. At the end, we cover some case studies in which DBA has been successfully used to verify design or particular conditions (such as heat treatments) for pressure vessels fabrication. The DBA calculation, described in this paper, is used with the same computational methods for high, medium or low pressure components, but it is clear that the most significant reduction in thickness is for high pressure components such as reactors, which is why the DBA calculation is particularly appreciated for this type of equipment. In the context of this paper “high pressure equipment” means when the ratio of the inner diameter to thickness of the walls is < 30.

Advanced High Strength Martensitic Stainless Steels for High Pressure Equipment

Maraging stainless steels offer a large panel of high strength materials with good ductility and stress corrosion cracking resistance. Their mechanical properties compared to conventional 15-5 PH and 17-4 PH martensitic stainless steels show much better yield strength / toughness compromise for yield strength exceeding 1300 MPa. In the same time, fatigue resistance is significantly increased at high strength stress levels and material keeps good resistance to stress corrosion. These properties make them particularly suitable for ultra-high pressure equipment or high pressure rotating components submitted to high cyclic stresses. Their application for Pascalisation pressure vessels and ultra-high pressure compressors for ethylene gas is briefly presented.