Failures and Unintended Component Applications

Extending the limits and the specification boundaries of components is common in innovative environments, as often a standard component does not exist yet for a new technology.  In this case, a pump designed to deliver low temperature liquids was used in an application due to its specified flow curve, operating pressures, and cost. The vendor specification did not

Compressor Filter Failure

This small compressor has a filter located on the upper port. The function of this compressor was critical to system operation and life time. Several systems using these compressors ran well for long periods, but ultimately a unit failed.  The post mortem analysis discovered a small piece of material in the outlet valve, and further investigation showed degradation of the filter material.
What went wrong? The filter, in this application, was being used was an exhaust filter designed for outbound flow., while the original configuration of the compressor was to be used as a vacuum pump. The person specifying the filter was unaware that the default setting set by the vendor was as a vacuum pump, nor that one filter could be configured in two ways. could be configured in more than one way.  
Prior to this failure, another problem plagued the system: an orifice manifold located near a hot entry point was being clogged with small brown chucks of material that were thought to be reversing through the system when the compressor was not running. The clogged orifice caused severe operating problems and resulted in the degradation and reduced the life expectancy of a downstream component nearly one quarter of the total system cost. The system was redesigned with expensive check valves to eliminate the reverse flow situation. After the compressor filter was found to be an issue, testing of old orifice was found to contain melted fibers from the filter and not material from back-flow.  That same filter caused these problems as well.
Concurrent engineering practices that involve persons who understand the consequences of even the simplest failures can reduce errors like this. The proper use of tools such as an FMEA may have identified this as a potential failure, but required a person knowledgeable enough to identify it. The FMEA in this case identified the compressor as a component and did not take the filter itself into consideration. It is critical to involve the right people early in the process to reduce failures and hidden lifecycle costs Blogger Labels: Case Study,FMEA,Compressor,Filter,Failure
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