one manhole for tanks between 1,000 gallons (4000 L) and 5,000
gallons (19 000 L). Provide a minimum of two manholes for
tanks larger than 5,000 gallons (19 000 L). Provide manhole
containment sumps for all manholes.
Interior Coatings. Coat underground operating tanks
in accordance with Section 8 of this handbook.
HYDRANT SYSTEMS. Decisions concerning major
rehabilitation of existing direct aircraft refueling systems
will be made by Service Headquarters. This paragraph
addresses existing direct aircraft refueling systems (Type I
and Type II) which can be rehabilitated or modified to meet
fuel quality standards, safety requirements, mission
requirements, and environmental regulations. All designs
should be accomplished by an engineering firm regularly
engaged in the design of direct aircraft fueling systems. The
provisions of Section 4 of this handbook are applicable.
Pumps. Repair or replace existing pumps to meet
increased fuel demands. Rebuild pumps including complete
bearing replacement, additional bowls or increased impeller
shortening to match replacement tanks, etc. In some cases,
additional capacity can only be achieved by total pump
replacement or rearrangement of piping. Consider pump
replacement where, due to equipment age or condition, it is
more economical to replace than to rebuild. Pump and motor
replacement may also result in higher efficiency units with
lower power demands and increased spare part availability.
Filter/Separators. Existing filter/separators must
be capable of meeting requirements of API Publ 1581. API
filters provide superior filtration and water removal required
of high performance aircraft. A majority of existing
filter/separators can be upgraded to the API elements.
Consider vessel replacement if the existing unit cannot be
converted to API elements or if the unit (with API elements)
fails to meet quality standards. Issue filter/separators
should be given priority for upgrade on a stand-alone project.
Upgrade of all filter/separators is mandatory on any major