be included as part of the project specifications.
The design of manholes including size, reinforcing,
arrangement, penetrations, equipment and piping
within the valve manholes is the responsibility of
the designer. Valve manholes shall be designed to
provide proper venting and drainage and adequate
room for maintenance without stepping on or over any
equipment. When electric sump pumps are used, the
electrical distribution and tie in points must be
designed and shown on the drawings.
In most cases, valve manhole covers will consist of
open grates. If manhole top is to be used as part
of a sidewalk and valve manhole is not deep, a solid
plate cover may be used without special provisions
for manhole ventilation. These tops must be
designed to be removed or opened completely during
maintenance operations. For larger and deeper valve
manholes, raised frame solid plate cover shall be
required.
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2.13.1
Valve Manhole Construction
Valve manhole dimensions shall be as indicated. The valve manholes shall
be constructed of reinforced concrete as indicated and in accordance with
Section [03300A CAST-IN-PLACE STRUCTURAL CONCRETE][03300N CAST-IN-PLACE
CONCRETE]. [Valve manholes shall be provided with a 762 mm 30 inch
standard cast iron frame and removable cover as a minimum, or a 900 by 900
mm 36 by 36 inch watertight, hinged steel cover not less than 13 mm 1/2 inch
thick.] Valve manholes shall be drained as shown. Concrete sections
shall not be less than 150 mm 6 inches thick. [The top shall be a cast
concrete slab of the same strength and thickness as the valve manhole or
fabricated from stainless steel, hot dipped galvanized steel or aluminum.]
[The top shall be [open grate cover] [or] [raised frame] [solid plate cover
(8 mm 5/16 inch thick checker pattern) conforming to ANSI H35.1].] [When
open grate covers are used for direct buried conduit systems, the top of
the grate will be at least 150 mm 6 inches above the surrounding grade.
When used for concrete shallow trenches, the top of the grate will be flush
with the concrete trench top. Open grates will be constructed of
galvanized steel. A checkered plate cover (also referred to as diamond
plate or embossed plate), shall be installed over the grating in colder
climates and where accumulation of trash is a problem. This checkered
plate shall be attached to the grating and shall be removable.] [Solid
plate covers shall be used for HTHW and steam/condensate direct buried
conduit systems only. Solid plate covers shall not be used for shallow
trench systems which are often used as sidewalks, or when substantial
loadings are expected. Ventilation openings shall be provided around the
entire perimeter below the raised top. The solid plate cover assembly
shall be removable. The cover, constructed of aluminum, shall also provide
sectionalized access for inspection and maintenance.] [When concrete covers
are used for direct buried conduit systems, the top of the concrete cover
shall be designed to be a minimum of 150 mm 6 inches above the surrounding
grade. When used for concrete shallow trenches, the cover shall be
designed to be flush with the trench top. Concrete requirements for this
cover shall be similar to those required for valve manhole construction.
Concrete cover shall be designed to support anticipated loadings. A 1220
by 1220 mm 4 by 4 foot aluminum access door (Bilco model JD-2AL or equal
SECTION 02560
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