25
STRATA1
17.0 hydraulic system
design
OS
AAV
C
LSV
DOC
CWM
Filling Point
Condense
Waste
Expansion
Vessel
Strainer
SV
IV
DOC
DOC
IV
Strata 1
Boiler
Heating Load
PS
IV
IV
1*
Typical single Strata 1 boiler installation serving heating only
where the boiler's own in-built circulating pumps are used to
circulate the water around the system (used only where system
index resistance < pump residual head - see page 24). Flow
temperature may be Fixed/constant or weather variable
OS=
Outside air temperature sensor, used where
direct-on-boiler weather compensated flow
temperatures are required
C=
Room temperature & time controls e.g.
RE2132 modulating room unit from MHS
Boilers, or, separate time clock & room
thermostat
PS=
Low water pressure cut off switch.
*1=
Filling Point. In accordance with BS 6644,
automatic pressurisation unit must be
installed when the boiler input is greater
than 60kW.
See item 17.1
System Type 1
