Pipelines and Hydrant Systems. All designs and installations must ensure
that maintenance personnel will be able to physically perform routine tasks
with tools and equipment readily available at the base. Items of
consideration should include:
a. Providing hydrant outlet pits or equipment pits large enough for
tool use in the pit while replacing or maintaining valves, flanges, pumps,
nut and bolts, e.g., to perform flange gasket replacement.
b. Ensuring that sufficient flanges are installed to permit ease of
pipe and equipment repair or replacement, e.g., pipe cutting or welding would
not be permitted in a pump house, therefore, flanges are required.
c. Providing sectionalizing valves in piping systems to shut down
piping sections for repair, maintenance and pressure testing.
d. Dikes or basins around storage tanks must be designed so that tank
cleaning, maintenance, and repair equipment can be easily transported into
the diked area. This includes providing clear access to the tank manholes
without climbing over or under pipelines.
e. Clearance must be provided between parallel buried tanks or other
structures so that each tank can be easily excavated and removed, e.g., tanks
may be too close together for mechanized equipment use.
f. Install sufficient isolation valves to repair system without
shutting off entire systems.
General design guideline for corrosion control:
Specify corrosion resistant materials, equipment and fixtures.
b. Specify copper alloys which are resistant to dezincification e.g.,
Design against dissimilar metal corrosion.
d. From a corrosion standpoint, stainless steel should not be used in
an environment void of oxygen or high in chlorides.
e. Aluminum should not be used in a highly alkaline environment such as
f. Seal all metal to concrete interface joints with silicone-type or
other appropriate sealant.