Abstract: A sash counterbalance device for a fume hood including a first cable having a first end and a second end, the first end being secured on the left side of a fume hood sash and wherein a first counterweight is secured on the second end of the first cable; a second cable having a first end and a second end, the first end of the second cable being secured on the right side of the sash, and wherein a second counterweight is secured on the second end of the second cable; and an axle which is mounted on the fume hood. The first and second cables are individually, separably, and concentrically wrapped about the axle such that movement of the sash causes a simultaneous movement of the axle by movement of the counterweights axle in a predetermined direction.

Abstract: A hydrocarbon vapor control system for preventing escape to the atmosphere, and for disposing of such vapors by clean burning. It includes a pair of adsorption beds and means for alternatively connecting them to receive the vapor while the other one of the beds is being regenerated with the effluent vapor from the regeneration being burned. There is a hydrocarbon detector at the outlet of each adsorption bed to determine when it has become saturated.A hydrocarbon vapor control unit includes a canister with an inlet at the bottom to admit the vapor. There is a support for an adsorption bed in the canister, and there is an outlet at the top which is designed to permit burning the effluent when the adsorption bed is being regenerated by air flow through the inlet.