5-06M
5.9.2.2 Testing to determine water table depth and, if direct buried systems
are applied, soil corrosiveness, soil type, moisture content, and pH. This
must be performed by a professional geotechnical engineer. Test samples
should be taken every 30 meters (100 feet) (minimum) along the routes of the
systems.
5.9.2.3 Review "as-built" drawings and interview VAMC maintenance personnel to
locate underground interferences.
5.9.3 Field work by the A/E or his consultant must be administered under the
terms of the contract between VA and the A/E.
5.10 Design of Direct Buried Systems:
5.10.1 The manufacturer is responsible for the design of the system within the
parameters of the VA specification. This responsibility includes insulation
types, pipe guides and anchors, end seals, corrosion protection, expansion
bends and loops, and carrier pipes. The A/E is responsible for all other
aspects of the design including manhole structure and piping, system
locations, profiles, pipe sizing, anchor location. The contract drawings
should include no details of the elements of the system for which the
manufacturer is responsible.
5.10.2 The condensate return piping shall not be included in the same conduit
as the steam piping. This will prevent condensate piping failures from
affecting the steam piping. Typically, condensate pipes have a much higher
failure rate than the steam pipes due to the acid corrosion that can occur if
water treatment is not correctly applied.
5.10.3 Depth of burial of the systems shall be 0.6 to 1.5 meters (two to five
feet) to top of conduit casing.
5.10.4 The A/E is completely responsible for the manhole design including
manhole structure, ventilation and piping.
5.11 Design of Concrete Shallow Trench Systems:
5.11.1 The A/E is completely responsible for the entire design including
concrete trenches, pipe anchors, sizing of expansion loops and bends, sizes of
expansion joints, pipe supports and guides, manhole structure and piping,
system locations, profiles, pipe sizing.
5.12 Design of Concrete Tunnel Systems:
5.12.1 The A/E is completely responsible for the entire design including
concrete tunnel, pipe anchors, sizing of expansion loops and bends, sizes of
expansion joints, pipe supports and guides, tunnel structure and piping,
system locations, profiles, pipe sizing.
5.12.2 The tunnel must include ample walking space with height for persons to
stand erect, and drain system to handle ground water and piping leaks.
5.12.3 Provide ample lighting and electrical receptacles designed for high
temperatures.
5.12.4 Provide ventilation systems to allow personnel to work safely.
5.13 Design Notes:
5.13.1 Provide pressure gages at the outlet side of all main steam valves so
that personnel can observe the gages while warming-up the steam line.
5.13.2 Provide steam drip traps and manual drains on steam lines at all low
points and upstream of all valves and pressure reducing stations. Spacing
shall not exceed 150 meters (500 feet).
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