In 2005, the City of Louisville (Kentucky) launched the Strategic Toxic Air Reduction (STAR) Program to address the presence of cancer-causing chemicals in the air around the city.
As shown in Figure 1, the addition of a thermal oxidiser significantly reduced stack emissions of 1,3 butadiene at the American Synthetic Rubber Company facility. However, a subsequent investigation in 2013 revealed ongoing fugitive emissions from more than 10,000 components in service would still cause the facility to exceed permissible limits.
Figure 1 (courtesy of ASRC)
The ASRC began a stringent monitoring program at BACT/LAER frequencies and limits (250 ppm) to determine which components had to be replaced.
One of the largest sources was from rupture discs. Many of the rupture disc installations were torqued incorrectly, making them prone to leakage both between the disc and rupture disc holder, and between the rupture disc holder and pipe flange (See Figure 2). In many cases, the torque values recommended by the rupture disc supplier conflicted with the recommendation for the specific gaskets used in butadiene service.
In 2016, ASRC partnered with OsecoElfab and began implementing the OsecoElfab Safety CartridgeTM in all butadiene rupture disc applications. As the OsecoElfab Safety CartridgeTM is a one-piece design with no recommended installation torque, the plant simply followed the torque values defined by the gasket manufacturer. The OsecoElfab Safety CartridgeTM eliminated the traditional leak paths between the rupture disc and holder, leaving only a solid bar stock surface exposed to the environment (See Figure 3). The implementation was completed in 2017.
Once installed and monitored, the facility noted previous rupture disc leakage was eliminated. With this reduction, the plant-wide fugitive emissions of butadiene were reduced by almost 50% in two years (Figure 4).
The OsecoElfab Safety CartridgeTM also reduced the plant’s installation time by 75%. Due to its ease of installation, downtime associated with overpressure events has been reduced by more than 60%, making the OsecoElfab Safety CartridgeTM popular with pipefitters and operations.
Figure 4 (courtesy of ASRC)
The OsecoElfab Safety CartridgeTM has proved to be the assembly of choice in all critical applications. It also aids with other common issues such as employee training and downtime associated with an overpressure event. Because of these additional benefits, the ARSC team has elected to continue installing the OsecoElfab Safety CartridgeTM in other difficult applications as a part of their normal change-out schedule.
Teksal Safety represents OsecoElfab in Western Australia and the Northern Territory.