Control valves

Desuperheaters

Steam atomizing desuperheaters (SAD)

A high pressure auxiliary steam supply is used to atomize the incoming water within the diffuser of the unit.

The auxiliary steam pressure needs to be at least 1.5 times the desuperheater inlet pressure with a minimum pressure of 3 bar g.

Internal

nozzle

Seals

Cooling water

Internal diffuser

Steam flow

Steam flow

Atomising steam

Application

-

High turndown applications where auxiliary steam is available, eg ;combined pressure reducing/desuperheating stations.

Mechanical design temperature and flange rating

Materials

<374 °C ASME 150, ASME 300, ASME 600 + PN16, PN25, PN40 Slip-on (Weld neck optional)

374 - 570 °C ASME 150, ASME 300, ASME 600 + PN16, PN25, PN40 Weld neck (Slip-on N/A)

Component

Mechanical design temperature

up to and including 425 °C

Mechanical design temperature

above 425 °C up to and including 570 °C

Shell ASTM A106 Grade B ASTM A335 P11

Atomising steam branch ASTM A106 Grade B ASTM A335 P11

Water branch ASTM A106 Grade B ASTM A335 P11

Flanges ASTM A105N ASTM A182 F11

Nozzle ASTM A182 F316L ASTM A182 F11

Diffuser ASTM A182 F316L ASTM A182 F11

Internal housing ASTM A350 LF2N ASTM A182 F11

Internal seals Soft copper Soft copper

TI-P475-01 CH Issue 3

Page 5 of 9

Direct Contact Desuperheaters

4.8.6