Page 253 - Improving Machinery Reliability

224 Improving Machinery Reliability

How to Keep Track of Reliability Review Tasks

As mentioned earlier, machinery reliability reviews are aimed at ensuring compli-
ance with all of the specification clauses invoked by the purchaser. In addition, the
reviewing engineer uses his own background and experience to determine whether
the proposed design, layout, construction features, etc. meet the long-term reliability
criteria established by the purchaser.
To assist him in executing these tasks, the reviewing engineer generally instructs
the contractor or equipment manufacturer to submit drawings and other data for his
review. Many of the vendor data and drawing requirements are tabulated in the
appendixes of applicable API standards and can be adapted to serve as checklists for
the task at hand. Other checklists may have to be derived from the reviewing engi-
neer’s experience.
Keeping track of the status of your documentation reviews is best accomplished
by first listing the vendor drawing and data requirements for a given machinery cate-
gory. Figures 3-99 through 3-103 represent these listings for the most prominent
machinery categories encountered in typical petrochemical process plants. Whenever
possible, the listings should contain the data requirements of available API stan-
dards. For instance, Figure 3-99 is derived from API Standard 617; the review engi-
neer may wish to use the versions found in the various current and applicable edi-
tions of API Standards.
Each “tracking sheet” is supplemented by three columns in which the reviewer
can enter the appraisal status (e.g., “Preliminary Review Completed,” “Comments
Forwarded,” and “Final (Corrected) Copy Reviewed”). Also, the “tracking sheet”
shows seven columns which indicate a particular job phase during which the vendor
or contractor is expected to submit certain drawings or analytical data for the equip-
ment owner’s review. The decision as to when (Le., during which job phase) data are
to be submitted is best made by mutual agreement of all parties involved.
We have reproduced reliability review checklists listing generalized rotating
machinery data review requirements for centrifugal compressors (Figure 3-99), spe-
cial-purpose steam turbines (Figure 3- IOO), centrifugal pumps (Figure 3-101), cooling
tower fan systems (Figure 3-102), and forced and induced draft fans (Figure 3-103).

Machinery Reliability Audits for Existing Plants

Experience shows that even a mature operating plant will benefit from periodic
reliability audits. As can be expected, machinery reliability audits look for factors
that could have, or in some cases already have had, an adverse impact on machinery
reliability, and therefore plant profitability. Machinery reliability audits differ from
conventional safety and plant operability audits by emphasizing the machinery-relat-
ed aspects of plant operation, organization, maintenance, troubleshooting, planning,
training, and other related functions. For example, individuals conducting a conven-
tional plant audit might simply review material control procedures by verifying the
existence of a parts and materials coding system; whereas, in a machinery reliability
audit, specific designation of critical spare parts would be recommended by, perhaps,