The MA-III/MA-IIIU is a multi nozzle mechanical atomizing desuperheater that reduces steam or gas temperatures by introducing cooling liquids directly into the hot fluid. The MA-III/MAIIIU is a probe style direct contact heat exchanger. The liquid passes through the main tube of the desuperheater to the spray nozzles and discharges into the steam header.

The MA-III/MA-IIIU is generally used for applications which feature steady and transient loads. The primary use is for interstage attemperation of high pressure and temperature superheated steam and is specially designed for intermittent use. It is well suited for applications where limited differential pressure is available for injection purposes. The MA-III/MA-IIIU is also designed for higher capacities than the MA-I and SAMN at the same time supporting wider range of the liquid flows.

This model is available in two mounting options. The MA-III is designed for welding to the pipe line and the MA-IIIU is flange mounted. The MA-IIIU also offers mounting commonality with other ‘U’-series desuperheaters (MA-IU, MA-IIU, MNSD-V and SAMN-U).

The standard MA-IIIU unit is flange mounted. The Injection tube is machined from a single forged bar. A uniquely designed cap is welded to the tube and to a specially machined 3" raised face weld neck flange. This design is better suited for thermal expansion and accommodates flanged header mounting, (universal bolted connection).

There are no special supports or adapters required for installation. The fitting material used for the header connection should be ASME SA-182 GR. F22/ASTM A182 GR. F22, which will match application requirements for high temperatures, minimize variations of field welds, and result in section I compliant materials.

A series of injection nozzles are fitted to the end of the injection tube and it is inserted through the header connection. The minimum bore diameter for a 3" connection is 2.90" for installation clearance.The standard water connection is a 2" socket or butt weld preparation. The butt weld connecting pipe schedule must match customer requirements to ensure proper end preparation.

A separate cooling liquid control valve is required. The controllability of the water is directly related to the nozzle performance. The nozzles operate between 30 and 500 psi differential pressure with full capacity of all nozzles being at 230 psi.