Boiler Safety Group with Connection to Expansion Vessel Afriso BSS G¾" (9061000)

The Afriso BSS G¾" boiler safety group is designed for connection to a diaphragm expansion vessel and for use in closed hot-water heating systems. The compact unit integrates pressure relief, non-return protection and system draining functions necessary for maintaining safe boiler operation. It enables controlled pressure relief when overpressure occurs, prevents backflow to safeguard the supply line, and allows filling and venting during commissioning or maintenance while providing a dedicated connection for an expansion vessel with a G¾" fitting.

Advantages

The boiler safety group combines several safety functions in a single assembly, reducing installation complexity and saving space. Its connection for a diaphragm expansion vessel supports stable system pressure and reduces risk of water hammer. The integrated pressure relief valve operates automatically to protect the boiler and piping from excessive pressure, while the non-return valve prevents reverse flow that could affect system performance. The drain and venting features simplify maintenance and commissioning tasks.

Suitable for

• Closed hot-water heating systems in residential and small commercial buildings
• Boilers that require connection to a diaphragm expansion vessel
• Applications where combined pressure relief, non-return and draining functions are needed
• Replacement or upgrade of existing safety groups with G¾" expansion vessel connection

Key specifications

• Connection to expansion vessel: G¾" female fitting
• Integrated functions: pressure relief valve, non-return (check) valve, drain/vent valve
• Intended system type: closed hot-water heating systems
• Material and finish suitable for heating system media contact (metal/plastic components where applicable)
• Compact assembly designed for wall- or boiler-mounted installation near the boiler circuit

How to use

Install the Afriso BSS G¾" unit on the boiler feed or return manifold according to local plumbing and heating regulations, ensuring a secure G¾" connection to the diaphragm expansion vessel. Verify orientation and mounting position to allow proper drainage and venting. During commissioning, use the filling and venting function to purge air from the system and adjust the system pressure to the required operating setpoint. The pressure relief valve will open automatically if system pressure exceeds its set threshold; after relieving pressure, inspect for leaks and verify correct operation of the non-return valve to prevent backflow.

Usage recommendations

Prior to installation, confirm compatibility with the boiler manufacturer’s specifications and the expansion vessel’s pre-charge pressure. Regularly inspect the assembly for signs of corrosion, leaks or blockages and perform periodic functional checks of the pressure relief and non-return mechanisms in accordance with local codes and maintenance schedules.