Submittal Sheet

253 series
Safety relief valve for solar heating systems. CE mark as per Directive 97/23/EC. TÜV certified for solar systems. 1/2” F x 3/4” F
threaded connections. Brass body. Chrome plated. Diaphragm and disk seal in high resistance elastomer. Spring of stainless steel
Control knob of PA6G30. Temperature range: -20 to 360ºF (-30 to 180ºC) . Nominal pressure: 150 psi (10 bar) . Calibration setting:
45, 60, 90, 120, 150 psi (3, 4, 6, 8, 10 bar). Medium: water and glycol solutions. Maximum percentage of glycol: 50%.
SPECIFICATION SUMMARIES
Operating principle
The valve disk (1), pressed by a
preset spring (2), raises off the seat
when reaching the preset pressure
and fully opens the outlet vent.
The preset pressure is chosen
according to the maximum
permissible pressure in the solar
heating system.
The diameter of the outlet
connection (3) is greater than the
inlet in order to help discharge
the required volume.
As the pressure decrease, the
opposite action, occurs with the
valve subsequently closing within
the preset tolerances.
Discharge pipe
Construction details
Temperature and glycol
In solar systems, heating fluid of the primary circuit contains glycol
as an additive and operates at high temperatures. Because of these
particular operating conditions, the valve disk seal of the safety
valve is made of high resistance elastomer.
The knob is made of plastic material especially resistant to increases
in temperature and to UV rays, in the case of outdoor installations.
Chrome plating
The valve body is chrome plated to protect it from dirt and moisture,
in the case of outdoor installations of solar heating systems.
Certification
253 series safety relief valves are certified for specific use in solar
heating systems by the certifying body TÜV, in accordance with
standard SV 100 Ed. 10.01 par. 7.7.
T Ü V Rheinland is an approved
U.S. Nationally Recognized Testing Laboratory (NRTL)
Installation
The safety relief valves for solar systems must be installed near the
point in the circuit where the system is filled - before the expansion
tank.
Make sure there are no shut-off devices between the valve and the
rest of the system.
The safety relief valves can be fitted vertically or horizontally but
not upside down. This prevents deposits of impurities from affecting
correct functioning.
The safety relief valves must be installed in line with the flow direction
indicated by the arrow on the valve body.
1
2
3
Application diagram
This valve should only be used and properly installed so that spillage
of glycol could not cause damage. To avoid damage due to valve
operation, a discharge pipe must be installed. It should terminate
approximately 12" (305mm) above an appropriate container or through
an air gap, as shown in the diagram,
piped into a suitable container or other
suitable place of disposal. Under no
circumstances should the vent opening
or drain line be plugged.