Page 37 - Root Cause Failure Analysis

28 Root Cause Failure Analysis

can be accomplished with just the data provided in these four documents. If the inves-
tigator lacks a basic knowledge of machine dynamics, review Part Two of this book,
Equipment Design Evaluation Guides.

Special attention should be given to the vendor’s troubleshooting guidelines. These
suggestions will provide insight into the more common causes for abnormal behavior
and failure modes.

Equipment Nameplate Data
Most of the machinery, equipment, and systems used in process plants have a perma-
nently affixed nameplate that defines their operating envelope. For example, a centrif-
ugal pump’s nameplate typically includes its flow rate, total discharge pressure,
specific gravity, impeller diameter, and other data that define its design operating
characteristics. These data can be used to determine if the equipment is suitable for
the application and if it is operating within its design envelope.

Procurement Specijications
Procurement specifications normally are prepared for all capital equipment as part of
the purchasing process. These documents define the specific characteristics and oper-
ating envelope requested by the plant engineering group. The specifications provide
information useful for evaluating the equipment or system during an investigation.

When procurement specifications are unavailable, purchasing records should describe
the equipment and provide the system envelope. Although such data may be limited to
a specific type or model of machine, it generally is useful information.

Vendor Specijications

For most equipment procured as a part of capital projects, a detailed set of vendor spec-
ifications should be available. Generally, these specifications were included in the ven-
dor’s proposal and conked as part of the deliverables for the project. Normally, these
records are on file in two different departments: purchasing and plant engineering.

As part of the design review, the vendor and procurement specifications should be
carefully compared. Many of the chronic problems that plague plants are a direct
result of vendor deviations from procurement specijications. Carefully comparing
these two documents may uncover the root cause of chronic problems.

Operating and Maintenance Manuals
O&M manuals are one of the best sources of information. In most cases, these docu-
ments provide specific recommendations for proper operation and maintenance of the
machine, equipment, or system. In addition, most of these manuals provide specific
troubleshooting guides that point out many of the common problems that may occur.
A thorough review of these documents is essential before beginning the RCFA. The