SMC's VCHN silencer is rated for high pressure of up to 5. 0MPa. A double-layer filtration structure results in less clogging of the silencer's element, and by simply removing a bolt, the sound absorbing material can be replaced without removing the silencer. The VCHN has a built-in safety valve, which will activate when the silencer's internal pressure exceeds 1. 8MPa. At a supply pressure of 4. 0MPa, back pressure 2. 0MPa, the VCHN provides a 35dB(A) noise level reduction. A freeze reduction option is available.