1-1/2″ BSP Expansion Silencer. The ES expansion silencers have been developed for the efficient reduction of noise from pneumatic valves releasing pressurised air into ambient air. Expanded/depressurised noise from the silencer depends on different variables, like connection line, silencer size and flow rates. When connected to 7 bar network, the silencer usually reduces noise by around 35dB. Typically noise does not exceed 85dB. The silencer cartridge is made of materials, resistant to freezing, which occurs when compressed air is expanded rapidly. Inner layer provides high throughput that prevents the surface getting saturated with ice. Prices exclude GST.