Safety valve 2115, 4.0 bar, 3/4 inch 2115.20.153

Protects heating systems from overpressure

Membrane safety valve 2115.20.153 acts as an automatic pressure limiter in closed heating circuits, especially where there is a risk of over‑pressure – e.g., in domestic hot water heaters. It opens only when pressure exceeds 4.0 bar, then automatically closes after it drops. It requires no manual intervention, has no adjustable settings – it operates solely based on the physics of the membrane and spring.

Suitable for residential and commercial installations

It can be installed in water systems, water‑glycol mixtures (up to a maximum of 50 % glycol content) and other non‑sticky fluids. The maximum allowable medium temperature is 110 °C – matching standard operating conditions of boilers and heat accumulators. The brass and spring‑steel construction coated with an anti‑corrosion layer ensures durability even with cyclic opening. The seal above the membrane allows system venting without valve removal.

Installation and service – simple but precision‑required

The valve must be installed vertically, with the inlet at the bottom – otherwise it will not function correctly. The upper insert can be unscrewed for cleaning the seat and membrane, allowing leak‑tightness to be maintained without replacing the whole device. The setpoint cannot be changed – it is fixed and designed for 4 bar. Continuous leaking does not indicate valve damage, but often points to a system design error – e.g., an undersized expansion tank or improper charging.

The 2115N version (with a stainless‑steel seat) is not this product – this model has a standard brass seat, but is sufficiently robust for most residential installations.