Safety Equipment To Din-En 12828; Requirements; Layout Of Safety Components To Din-En 12828 - Bosch UT-L 1 Technical Manual

52 | System examples
9.2

Safety equipment to DIN-EN 12828

9.2.1

Requirements

No claim is made as to the completeness of the diagrams
or the corresponding design information for the system
examples. Each system example is a non-binding
recommendation for certain versions of the heating
system. The practical implementation is subject to
currently applicable technical rules. Safety equipment
should be installed in accordance with local regulations.
DIN EN 12828 determines the safety equipment level.
The schematic illustration in Fig. 34 can be referred to as
an engineering aid.
9.2.2

Layout of safety components to DIN-EN 12828

Boiler > 300 kW; operating temperature ≤ 105 °C;
shutdown temperature (high limit safety cut-out)
≤ 110 °C – direct heating
11
0,5 %
6/7
8
1)
3
> 300 kW
12 13
Fig. 34 Safety equipment to DIN-EN 12828 with direct
heating
[RK] Return
[VK] Flow
[1] Heat sources
[2] Shut-off valve, flow/return
[3] Temperature control unit
[4] High limit safety cut-out (STB)
[5] Temperature capturing facility
[6] Diaphragm safety valve MSV 2.5 bar/3.0 bar
Lift spring safety valve HFS ≥ 2.5 bar
[7]
[8] Flash trap (ET); not required if a high limit safety
cut-out with a limit ≤ 110 °C and a maximum
pressure limiter are additionally provided for each
boiler.
[9] Maximum pressure limiter
[10] Pressure gauge
[11] Low water indicator (WMS) or a minimum pressure
limiter
[12] Non-return valve
[13] Boiler drain & fill valve (KFE)
[14] Expansion line
6 720 807 794 (2013/04)
VK
2
1)
5
10 9
P
15
13
1)
4
1
15
14
16
17
2 13
RK
6 720 640 417-14.1il
[15] Shut-off valve – protected against unintentional
closure, e.g. by sealed cap valve
[16] Drain upstream of the expansion vessel
[17] Expansion vessel (DIN-EN 13831)
1)
[ ] The maximum achievable flow temperature in
combination with CFB control units is approx. 18 K
below the shutdown temperature (high limit safety
cut-out).
UNIMAT