19
Wavin AS+
Technical Manual
4.2. List of definitions according
to DIN EN 12056
Waste water drainage system
Structural system for the collection, drainage, disposal
and treatment of waste water in buildings and on private
property.
Underground collector pipe
A non-accessible pipe, installed below ground or in the
foundations, for the disposal of waste water (normally via the
connecting sewer)
Collecting pipe
Horizontally installed pipe for the collection of waste water
from downpipes and connected lines not buried below
ground or installed in foundations
Downpipe
Perpendicular pipe for the collection of waste water from
individual and collective inlets. It directs the flow of waste
water to a collecting pipe or underground and collector pipe
Collecting connection pipe
Pipe designed to collect waste water from various single
connection pipes and direct it to a downstream pipe
Single connection pipe
Pipe from a sink drain or other drainage outlet, designed to
direct waste water to a downstream pipe
Bypass pipe
Pipeline for connection pipes in the retention area of a
downpipe offset or in the transition between a downpipe and
a collecting pipe or underground and collector pipe
Discharge unit (DU)
The average discharge rate of a sanitary appliance expres-
sed in litres per second (l/s)
Frequency factor
Variable to take into account the frequency of use of sanitary
appliance (dimensionless)
Waste water flow rate (Q
ww
)
Total design flow rate from sanitary appliances in a drainage
system or in a part of a drainage system in litres per second
(l/s)
Continuous flow rate (Q
c
)
Flow rate of all continuous flows, e.g. cooling water, etc. in
litres per second (l/s)
Pumped water flow rate (Q
p
)
Discharge rate of waste water pumps in litres per second
(l/s)
Total flow rate (Q
tot
)
The total flow rate is the sum of the wate water flow rate
(Q
ww
) and continuous flow rate (Q
c
) and pumped water flow
rate (Q
p
) in litres per second (l/s)
Hydraulic capacity (Q
max
)
Maximum flow rate of air through a ventilating pipe or air
admittance valve, measured at 250 Pascal (Pa) pressure
drop, in litres per second (l/s)
Types of system
The many types of drainage system that currently exist are
a result of widely ranging areas of application for sanitary
equipment in different countries and the variety of technical
procedures and regulations that govern such systems.
