Page 93 - Improving Machinery Reliability

Vendor Selection and Bid Conditioning 65

attempts to give guidance in this regard. It explains selection procedures that have
given satisfactory results in a large number of major refinery and chemical plant
construction projects. More important, though, it shows how vendor selection and
equipment selection criteria interact and must be given simultaneous consideration.

Standardization Within What Limits?

A petrochemical plant obviously would not find it practical to purchase equipment
from boo many manufacturers. Spare parts identification, procurement, and ware-
housing are expensive and leave margin for error. Also, it would be progressively
more costly and difficult to train mechanical workforces for full proficiency in too
many equipment types or models.
On the other hand, standardizing on too few manufacturers may deprive the user
of optimally selected equipment. There is obviously no single manufacturer of cen-
trifugal pumps who can lay claim to products that are consistently more efficient,
easier to maintain, and more rugged than competitive equipment.
Experience shows that two or three vendors could adequately cover the on-site
pumping services of a typical petrochemical plant. Five or six manufacturers should
be invited to submit bids, and two or three of these subsequently selected for con-
tract award. Off-site pumps, frequently of ANSI or ISO-type, could be selected from
one additional vendor among those who had been invited to bid.
Highly specialized centrifugal pumps for critical services, such as high-pressure
boiler feedwater or pipeline supply pumps, may have to be purchased from the most
experienced source, regardless of whether the vendor is among those selected for on-
site and off-site pumps. Purchase of these special pumps should be handled separate-
ly on an individual basis, rather than being lumped with other pumps.

Assessing Vendor Experience
Three principal characteristics identify a capable, experienced vendor:

1. He is in a position to provide extensive experience listings for equipment
offered.
2. His marketing personnel are thoroughly supported by engineering departments.
Both groups are willing to provide technical data beyond those that are custom-
arily submitted with routine proposals.
3. His centrifugal pumps enjoy a reputation for sound design and infrequent main-
tenance requirements.

With a large: project involving 200-300 or more pumps, it is often necessary to
delegate to the contractor’s equipment engineers the responsibility of verifying ven-
dor experience with other users. For certain critical services (e.g., high-pressure boil-
er feedwater pumps, large cooling-water pumps, multistage pipeline or feed pumps,
etc.), the owner’s engineer would be well advised to check for himself. When