Steam Trap Monitoring
Figure 1: Wireless data indicated serious problems with a quarter of Genentech's traps.
The second asset able to benefit from performance-based maintenance was critical research equipment. Ultra-low freezers are critical to research activities. Reliability issues with older, stand-alone freezers result in downtime and potential loss of work product. Maintenance on the freezers is performed frequently to avoid these issues. Performance-based monitoring of these research freezers would allow the maintenance staff to proactively detect issues and prevent failures. This would increase freezer uptime and could potentially extend their useful life.
Avoiding Invasiveness
However, the typical challenges with implementing performance-based maintenance on existing systems include cost and invasiveness. In order to monitor the condition of assets, analog instruments must be replaced, or new instruments must be installed to collect data. Traditionally, this work is invasive and requires a process interruption and engineering oversight. Furthermore, the new system must be commissioned for restart. This often includes inspections and leak checks, as well as revalidation in order to return the system to service. These activities often result in an unfavorable cost/benefit ratio.
As a cost-effective alternative, we identified a non-invasive monitoring solution, provided by Cypress Envirosystems (www.cypressenvirosystems.com). Devices are clamped onto existing instrumentation to collect and then wirelessly transmit data to a server for trending and alarming. This method eliminates the need for process interruption for installation and minimizes engineering oversight.
However, we were concerned about the viability of a new wireless technology in the facility. Although the traditional monitoring solution was more challenging to implement, it was a technology that was commonly used on campus. With the non-invasive wireless solution, there were concerns with data integrity, wireless security and data integration into the existing infrastructure. To demonstrate proof of concept, as well as to quantify potential savings, Genentech partnered with Cypress Envirosystems to pilot this technology on specific equipment.
Securing Savings
Subsequently, wireless steam trap monitors (WSTMs) were installed on 56 steam traps at a cost of $42,000. The WSTMs were intended to provide early indication of steam leakage or blockage, which could lead to failure. Data was collected on a "blue box" server for trending analysis.
As a result, 14 steam traps showed signs of failure. The maintenance team investigated, and the traps were replaced. Early detection saved an estimated $53,000 in annual steam loss. The project payback was 10 months.
Also, wireless freezer monitors (WFMs) were installed on 20 critical freezers at a cost of $20,000. The WFMs measured parameters including low-stage and high-stage compressor amperage, internal chamber temperature and door open/close status. The data collected was intended to provide early indication of refrigerant leaks or door seal issues, which lead to freezer failures.
Four freezers showed signs of distress. Even though the temperature profiles of the freezers showed no problems with freezer functionality, the compressor amperage profiles indicated that freezer failure was imminent (Figure 2). The issues were investigated and resolved by the maintenance team without having to replace the freezers.