The Mark 33 is a motor operated valve featuring a Jordan sliding gate seat and heavy-duty industrial motors for proportional (resistance), on-off, 4-20mA electronic control. Models include the Mark 33 in sizes 1/4" through 2" (DN8 through DN50), the high flow Mark 331/332 with Cv's up to 70 (60,34Kv), and the Mark 39 with three-way body.

The Mark 33 delivers exceptional pressure drop capabilities due to the short stroke of the sliding gate seat which permits greater utilization of the motor torque output. Power is transmitted via a cam, allowing the valve to handle higher than usual pressure drop conditions.