Safety valve 2115, 4.0 bar, 1/2 inch 2115.15.153

Pressure relief protection in closed systems

Safety valve 2115.15.153 acts as a membrane protective mechanism that opens automatically at a pressure of 4.0 bar to prevent damage to the installation. It is intended mainly for use in closed domestic hot water heaters, where sudden pressure spikes can cause tank or pipe failure. No manual operation is required – it reacts only when the set value is exceeded.

Construction and operation

The housing and internal components are made of brass, providing corrosion resistance in a water environment. The membrane and seat sealing are made of a material resistant to high temperature and ageing, allowing safe operation at a maximum medium temperature of 110 °C. The spring is coated with a galvanic coating – protecting it from oxidation, especially during long‑term use.

The valve cap can be unscrewed to inspect or clean the seat – the whole device does not need to be disassembled. This facilitates service without draining the entire system. The design prevents accidental adjustment of the opening setting – it cannot be “turned” manually, eliminating the risk of installation error.

Application and limitations

It can be used in installations with clean water, steam, gases or other non‑sticky fluids. Use of a water‑glycol mixture is also permitted – but the glycol content must not exceed 50 %. Installation should be vertical, with inlet from the bottom – this is a condition for proper membrane operation and venting above it.

The valve has PZH certification and meets UDT requirements for pressure equipment. If dripping persists after cleaning – do not attempt further repair. Replace with a new one: this is the only safe way to maintain the protective function.

For glycol installations or frequent opening cycles – consider model 2115N with a stainless steel seat, but this model (2115.15.153) is the standard solution for most residential heating systems.