Control valves

Desuperheaters

4.8.5

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

374 - 525 °C ASME 150, ASME 300, ASME 600 + PN16, PN25, PN40 Weld neck (Slip-on N/A)

375 - 570 °C ASME 300, ASME 600, ASME 900, ASME 1500 + PN10, PN16, PN25, PN40, PN63 and PN100 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

Sizes 1 to 2:

ASTM A350 LF2N

Size 3 and above: ASTM A106 Grade B

Sizes 1 to 2:

ASTM A182 F11

Size 3 and above:

ASTM A335 P11

Water branch

Sizes 1 to 2:

ASTM A350 LF2N

Size 3 and above: ASTM A106 Grade B

Sizes 1 to 2:

ASTM A182 F11

Size 3 and above:

ASTM A335 P11

Flanges

Sizes 1 to 2:

ASTM A350 LF2N

Size 3 and above: ASTM A105N

ASTM A182 F11

Nozzle

ASTM A182 F316L

ASTM A182 F11

Internal diffuser

Sizes 1 to 2:

Not applicable

Size 3 and above: ASTM A182 F316L

Sizes 1 to 2:

Not applicable

Size 3 and above:

ASTM A182 F11

Internal housing

Sizes 1 to 2:

Not applicable

Size 3 and above: ASTM A350 LF2N

Sizes 1 to 2:

Not applicable

Size 3 and above:

ASTM A182 F11

Main diffuser

Sizes 1 to 4:

Sizes 6 and 8:

Size 10:

Size 12 and above:

ASTM A350 LF2N

ASTM A240 / ASTM A312 316L

BS EN 10130:2006 DC01

ASTM A516 Gr70

Sizes 1 to 4:

ASTM A182 F11

Sizes 6 and above: ASTM A387 Gr11

Internal seals

Soft copper

Soft copper

Venturi type desuperheaters (VTD)

The venturi principle is used to create regions of high velocity and turbulence which produces intimate contact between the steam and

cooling water.

Internal diffuser

Seals

Cooling water

Main diffuser

Internal nozzle

Steam flow

Application

-

Suitable for most general plant applications, except where high turndowns on cooling water are required.

-

Flow turndowns between 3:1 and 10:1 depending on conditions.

Mechanical design temperature and flange rating

Materials

Page 4 of 9

TI-P475-01 CH Issue 3

Direct Contact Desuperheaters