Process Safety Progress | Year: 2014
Layers of Protection Analysis evaluates the sequence of events that first initiate and then propagate to a hazardous event. This semiquantitative risk assessment technique can expose the role that automation plays in causing initiating events and in responding to the resulting abnormal operation. Automation that is specifically designed to achieve or maintain a safe state of a process in response to a hazardous event is now referred to as safety controls, alarms, and interlocks (SCAI). Guidelines for Initiating Events and Independent Protection Layers addresses four basic types of SCAI: safety controls, safety alarms, safety interlocks, and safety instrumented systems. This article discusses the design, operation, maintenance, and testing practices necessary for SCAI to be considered as independent protection layers (IPL). It also provides guidance on claiming multiple layers of protection in the basic process control system. © 2013 American Institute of Chemical Engineers.
Solutions | Date: 2010-07-23
A method and apparatus for molding a plurality of tiered containers from a single parison. Two or more parisons can be arranged next to each other. A molding apparatus of this invention can have one or more mold sections that can be operated in a controlled fashion to form a stacked or tiered arrangement of containers from a single parison or can be arranged to form an array of containers including two or more columns of containers each having two or more tiered containers, all during a single cycle of the molding apparatus. Each container formed by the method and apparatus of this invention can be blow molded and/or vacuum formed and/or filled and/or sealed. Each seal can be a hermetic seal or any other suitable seal formed through a molding step.