If a system has a high operating pressure, water when flowing has a greater momentum which when brought to a sudden halt, will create a shock effect causing pipes to shudder and vibrate. This is normally caused by the rapid closure of lever operated taps or valves, solenoid valves or valves in dish washers and washing machines. The Altecnic pneumatic shock arrester or water hammer arrester is designed for a single outlet, such as a tap or washing machine, or a small group of services, such as a bathroom supplied via a manifold. The vibration caused by water hammer is not only annoying but eventually can result in split or cracked pipe fittings, especially at joints. The Altecnic water hammer arresters are maintenance free and can be installed in any orientation.

The arresters should be installed close to the tap or valve minimising the effect of the shock on the system. The water hammer arresters are suitable for use in coastal environments and with brackish water due to their stainless steel construction.

Operating Principle
The water hammer arrester consists of a pressure vessel, divided into two chambers by a flexible rubber membrane or diaphragm. The closed chamber is filled with air, pressurised to 3.5 bar, which acts as a damper due to the compressibility of the trapped air. The open chamber is connected directly to the system and is filled with water. When a pressure surge occurs, the air acts as a cushion which compresses causing a small change in volume which absorbs the excess pressure.