Elliptical Pipe
Elliptical pipe is manufactured for special applications. Horizontal elliptical
pipe is sometimes called ‘low head’ because the pipe can be placed
where the available head room precludes the use of a standard round section. Where
lateral clearance is limited, a vertical elliptical pipe can be provided. There
is a major difference between horizontal and vertical elliptical pipe in the
placement and amount of the reinforcement to resist vertical loading on the pipe.
Applicable Specifications and Recommended Use
ASTM C 507 Reinforced Concrete Elliptical Culvert, Storm Drain, and Sewer
Pipe
C 507 Horizontal Elliptical pipe is used for sizes 18" - 144" equivalent
circular sizes with tongue and groove cement mortar or mastic compound joint. The
horizontal elliptical pipe is installed with the major axis horizontal and is
used for minimum cover situations or other conditions where vertical clearance
problems are encountered. It offers the hydraulic advantage of greater
capacity for the same depth of flow than most other structures of equivalent
water-way area. Loads under similar cover conditions are similar to that
of circular pipe with the same span.
C 507 Vertical Elliptical pipe is used for sizes 36" - 144" equivalent
circular sizes with tongue and groove cement mortar or mastic compound joint. The
vertical elliptical pipe is installed with the major axis vertical and is used
for minimum horizontal clearances are encountered or where unusual strength characteristics
are desired. Hydraulically, it provides higher flushing velocities under minimum
flow conditions and carries equal flow at a greater depth than equivalent horizontal
elliptical, arch, or circular pipe. Loads under similar cover conditions are
similar to that of circular pipe with the same span.
Joints
Cement Mortar and Mastic Compound
All pipe, special shapes and boxes are available with tongue and groove joints
that may be packed with cement mortar, filled with a preformed plastic gasket
sealing compound, or a trowel applied mastic compound. Such joints have
a successful experience record and are generally used for storm sewer construction. Properly
applied mastic joint fillers provide flexibility without impairing water tightness.