Datasheet

90 ˚C
TRV
RTD-CB
min. 175 mm
Heat cost
allocator
RTD-BR
90 ˚C
TRV
RTD-CB
min. 175 mm
RTD-BR
Heat cost
allocator
DKCD VDCHA102 © Danfoss 12/2007 1
Data sheet Flow Restrictors for one-pipe systems
Application
The RTD-CB back-ow restrictor prevents radiator
back-ow and heat transfer at the return pipe in a
one-pipe system.
The back-ow restrictor is installed in the radiator
return pipe with the bow pointing upwards.
Ordering and data
Type Size
Connections
K
VS
Max.
working
pressure
Test
pressure
Max.
working
temp.
Code no.
Inlet Outlet
RTD-CB back-ow restrictor DN 15 R 1/2 Rp 1/2 4.54 m
3
/h 10 bar 16 bar 120 ˚C 013L1925
RTD-CB back-ow restrictor DN 20 R 3/4 Rp 3/4 8.06 m
3
/h 10 bar 16 bar 120 ˚C 013L1926
RTD-CB back-ow restrictor DN 25 R 1 Rp 1 17.0 m
3
/h 10 bar 16 bar 120 ˚C 013L1927
RTD-BR bypass restrictor DN 15/10 G 1/2 G 1/2 6.80 m
3
/h 10 bar 16 bar 120 ˚C 013L1915
RTD-BR bypass restrictor DN 20/15 G 3/4 G 3/4 15.1 m
3
/h 10 bar 16 bar 120 ˚C 013L1916
RTD-CB back-ow restrictor RTD-BR bypass restrictor
The RTD-BR bypass restrictor decreases ow
through the bypass in a one-pipe system, thus
forcing the correct amount of system water to
pass through the radiator.
The bypass restrictor will decrease the bypass
with one dimension ( e.g. DN 20 > DN 15).
The bypass restrictor is installed in the bypass by
the radiator.
Principle
Radiator Convector
The RTD-CB back-ow restrictor reduces heat
transfer from system pipes to radiator, when the
TRV is closed.
With the bypass placed 175 mm from the radiator,
a ow temperature of 90 ˚C and a room tempera-
ture of 20 ˚C, the max. detected temperature is:
The heat cost allocator is placed according to the manufacturer’s instructions.
Heat transfer
Heat cost allocators with a single
sensor for radiator surface
28 ˚C
Heat cost allocators with two
sensors for radiator surface / room
temperature
room temp.
+ 5 °C