DRAIN PIPES AND ITS TYPES

DRAIN PIPES AND TYPE OF PIPES

PREETHI.D

Storm drain design generally consists of three major parts :  CATCHMENTS - System planning which includes that gathering and outfall location;  INLETS AND GUTTERS - Pavement drainage which includes pavement geometries and inlet spacing;

 STORM WATER REGULATORS AND CATCH BASINS - Location and sizing of the mains and manholes.

LAND SURFACE CATCHMENTS  Ground or Land surface catchment areas are less complex way of collecting rainwater.  It involves improving runoff capacity of the land surface through various techniques including collection of runoff with drain pipes and storage of collected water.  By retaining the flows (including flood flows) of small creeks and streams in small storage reservoirs (on surface or underground) created by low cost (e.g., earthen) dams, this technology can meet water demands during dry periods.

 There is a possibility of high rates of water loss due to infiltration into the ground, and, because of the often marginal quality of the water collected, this technique is mainly suitable for storing water for agricultural purposes.

Various techniques available for increasing the runoff within ground catchment areas involve:  Clearing or altering vegetation cover  Increasing the land slope with artificial ground cover  Reducing soil permeability by the soil compaction  application of chemicals

DROP INLETS A location where storm water runoff from an open area enters the storm drain system.

Drop inlets are usually part of the public drainage system, but can sometimes be considered private.

LOCATION May be located either on a continuous grade or in a sag location.Part of the gutter flow can bypass the inlet in case of the Inlets on continuous grade (carry over, bypass or runby flow)

STORM WATER INLET TYPES    

Gutter (grate) inlets Curb opening inlets Slotted drain inlet Combination inlets

 Grates of the inlets can be reticular, rectangular or parallel bar  Located on road sides at 30 to 60 m distance at low points and at cross slope reversal points  Inlets in sag are located at points where runoff from a given area ultimately accumulates  Open into catch basins and connected to nearby manholes of the sewerage system  Have clear opening of ≤25 mm size

GUTTER INLET

CURB OPENING INLET

SLOTTED DRAIN INLET

COMBINATION INLET

GUTTERS  Street gutter is a depression which runs alongside a city street, usually at the curb and diverts rain and streetcleaning water away from the street and into a storm drain

CULVERTS  A culvert is a drainage pipe used to convey a stream through a road or embankment or may carry a stream for a long distance underground to a surface discharge location  Culverts are generally short in length and open at both ends and often must withstand substantial traffic loads

CULVERTS

DITCHES ďƒ˜ Constructed to convey water from storm runoff to an adequate outlet. ďƒ˜ A good ditch is shaped and lined using the appropriate vegetative or structural material and does not cause flooding, erosion, or sedimentation.

FLAT BOTTOM DITCH

U- SHAPED DITCH

V -SHAPED DITCH

ROUNDED V SHAPE DITCH

STORM WATER REGULATORS  Used to divert part of the sewage from combined sewer into a natural stream or river.  The regulators include leaping weir, overflow weir and siphon spillway

LEAPING WEIR  It is the term to include the gap or opening in the invert of a combined sewer. The intercepting sewer runs at the right angles to the combined sewer.  When the discharge is small the sewerage falls directly into the intercepting sewer through the opening. But when a discharge exceeds a certain limit, the excess sewage jumps out and is carried by natural stream.

SIPHON SPILLWAY This arrangement of diverting excess sewage from the combined sewer is most effective because :

 It works on the principle of siphon action and the rise of sewage in combined sewer is thus controlled in a better way.  It is automatic in functioning and most effective.  No moving parts therefore low maintenance.

OVERFLOW WEIR  In this the excess sewage is allowed to overflow in the channel made in the manhole.  When the quantity of sewage exceeds the capacity of the combined sewer it overflows and falls into the channels and it is conveyed to the storm water sewer

FLOAT ACTIVATED GATES AND VALVES

 Automatic mechanical regulators actuated by water level in the sump  These regulators involve moving parts and require periodic maintenance  Flap gates and flood gates are installed at or near sewer outlets to prevent backflow of water

CATCH BASINS  Masonry chambers of 75-90 cm dia. & 75-90 cm depth provided along the storm sewer (or combined sewer) line for collecting and clarifying storm water and allowing into the storm sewer.  Storm water inlets open into these catch basins and outlets of these basins provided 60 cm above the basin bottom convey storm water into the sewer.  Frequent maintenance (degritting and cleaning) of the catch basins is required.