suitable abutting surfaces will be permitted. The use of dissimilar metals separated
by an insulating material will also be permitted. Dissimilar metals are defined in
3.4.4 Reclaimed materials. The use of reclaimed materials shall be encouraged
to the maximum extent possible without jeopardizing the integrity of the item.
3.5 Design and construction. The purging unit shall be so designed and
constructed that no parts will work loose in service. The purging unit shall
withstand the strains, jars, vibrations, and other conditions incident to shipping,
storage, installation, and service.
3.5.1 Heating element and exchanger. The heating element and heat exchanger
shall be so designed that either can be replaced as separate components.
The purging unit shall he designed to meet the requirements
3.5.3 Maintainability. The purging unit shall be designed and constructed as
specified herein and to provide the following:
a. Minimum number of parts consistent with reliability and performance
b. Minimum amount of training and time necessary for assembly, disassembly,
location of trouble sources, and maintenance including servicing. Where
practical, parts and components shall be located or positioned for rapid
and simple inspection and recognition of excessive wear or potential
c. Permit adjustments, servicing, replacement of parts and components, and
other maintenance with minimum disturbance to other equipment parts or
components. Parts and components shall be located for ample and rapid
access unless performance or reliability will be appreciably degraded by
the accessible location. If engineering reasoning or data determines
that in performing maintenance, physical or visual interference between
items cannot be avoided, where practical, the item predicted to require
the most maintenance shall be located for best accessibility.
d. The manufacturer shall be prepared to provide all technical data required
to operate, repair and functionally test the assembly, including an
illustrated parts breakdown of the assembly.
e. The manufacturer shall be prepared to provide replacement parts for the
assembly when needed to accomplish repairs.
f. Maintenance with general purpose tools and equipment normally available
commercially. Use of specific purpose tools and equipment shall be
subject to contracting activity approval.
g. Minimum number of tools required for maintenance by design practices such
as reducing the variety of bolthead sizes to the practicable minimum.
The configuration of the purge kit shall be in accordance
with Figure 1.