Model 310

Description

ABBITZ™ Differential Pressure Unit (DPU) serves as an actuating unit for a wide variety of instruments.     Featuring ABBITZ’s™ new edge welded  rupture-proof bellows. Also functions as a drop-in replacement for Barton’s® M199 DPU. Each DPU consists of a Bellows Unit Assembly (BUA) and removable pressure housings. Within the BUA, flexible bellows are secured to a centerplate. In dual-bellows models, the movable bellows are rigidly connected by a dual valve stem that passes through the centerplate. Valve seats, in the centerplate passage, form a seal with the valves. Contacting the valve stem in the centerplate is a drive arm pivoted on the end of a sealed torque tube. The bellows is filled with a clean, noncorrosive, low-freezing point liquid. A range spring assembly provides tension against applied pressures. In operation, pressure is applied to both sides of the bellows. Any difference in pressure causes the bellows to move until the spring effect (range springs) balances out the force. The linear motion of the bellows (proportional to the DP) is transmitted as a rotary motion through the torque tube. In dual-bellows units, if the bellows are subjected to a DP greater than the unit’s DP rating, a valve closes and “traps” the fill liquid in the bellows — fully supporting the bellows and preventing rupture. Since opposing valves are used, full protection is provided in either direction.