Installation
4.3
Safety valve
The safety valve must comply with DIN 4753 Part 1 paragraph 6.3.2. Position the safety valve vertically and in
an easily accessible location.
Safety valve and outlet line sizes
Nominal capacity of the
storage tank
Up to 200 l
Over 200 to 1000 l
Over 1000 to 5000 l
If the storage tank's heating capacity is above the allocated nominal capacity of the water room, a safety valve
must be selected that suffices for the heating capacity.
The safety valve activation pressure must be not higher than the storage tank's operating pressure!
The following information must be attached to the safety valve pursuant to DIN 4753 Part 1 section 6.3.4.2:
Safety valve outlet line
No-one must be at risk from escaping hot water and steam. Outlet lines from two or more safety valves must
individually and openly eject such substances via an outlet point.
The outlet line must be designed to be the same size as the safety valve's outlet section, must not have more
than two bends and must have a maximum length of 2 m. If more bends or a greater length are unavoidable, a
larger version of the entire outlet line must be used. More than three bends and a length of more than 4 m are
not permitted. The end of the outlet line must protrude 20 - 40 mm over a drainage system or drain funnel and
be visibly positioned. The end of the outlet line must be positioned in a frost-resistant area.
Excess pressure in the storage tank
During the heating process, the storage tank capacity expands. If the excess pressure is
not restricted, the storage tank can be destroyed.
Warning!
► The safety valve must be ready for operation at all times.
► Escaping water must be visibly fed off into a waste water pipe.
4.4
Pressure-reducing valve
The maximum pressure in the cold water pipe must be 20 % below the safety valve activation pressure. If the
maximum pressure of the cold water pipe is higher than this, a pressure-reducing valve must be installed.
Maximum pressure in
the cold water pipe
4.8 bar
4.5
Thermometer
According to Article 5.11 of W/TPW 115 from the Swiss Gas and Water Industry Association, a thermometer
must be installed in the storage tank from a nominal capacity of 120 litres (article number : Z21386).
22.12.2017
Copyright 2017 by: WATERKOTTE GmbH. Subject to change without notice.
Max. heating capacity
75 kW
150 kW
250 kW
For safety reasons, no water must escape from the outlet line
during heating!
Do not seal!
Permissible storage tank
operating pressure
6 bar
28 / 60
Min. valve size
DN 15
DN 20
DN 25
Storage tank test
pressure
(in relation to drinking
water)
12 bar
Min. connection
diameter
inlet – outlet
R/Rp ½ – R/Rp ¾
R/Rp ¾ – R/Rp 1
R/Rp 1 – R/Rp 1¼
Safety valve activation
pressure
6 bar
Z21339