5221 Fire-rated partitions (12) Partitions of proprietary or non-proprietary construction, including plenum and ceiling barriers, to provide a specified fire-rating 5222 Acoustic-rated partitions (35) Partitions of proprietary or non-proprietary construction, to provide a specified sound attenuation 5223 Heat-insulated partitions (0) Partitions of proprietary or non-proprietary construction erected between areas within a building with different levels of temperatures and relative humidity 5224 Proprietary service wall partitions (0) Proprietary partition systems, supported on metal framing, designed to accommodate building services and to support equipment and shelving, storage units, etc., with removable panels to provide access to the building services sometimes pre-fabricated 5225 Operable walls (22) Operable partitions, of framed or frameless glass, solid doors, etc., usually top-hung but sealed to the floor when at rest but capable of being moved and stacked and maintaining fire-rated and/or acoustic performance at rest 5226 Ballistics/security partitions (0)