Control valves

Self-acting controls

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Kv values

Size

KA31, KA33

KB31, KB33

KC31

-

-

-

-

16.4

8

34.00

For conversation:

Cv (UK) = Kv x 0.963

Cv (US) = Kv x 1.156

Capacities

For saturated steam sizing capacities see TI-GCM-08.

For water valve sizing capacities see TI-GCM-09.

Dimensions/weights (approximate) in mm and kg

KA31 and KA33

Spare parts

The spare parts available are shown in solid outline. Parts drawn

in broken line are not supplied as spares.

DN15 DN20 DN25 DN32 DN40 DN50

2.90

4.64

9.80

16.48

23.70

34.00

-

-

9.80

16.48

23.70

34.00

Available spares

KA31 and KA33

Valve seat assembly

Set of all gaskets

Set of bonnet studs and nuts (set of 4)

KB31, KB33 and KC31

Valve seat assembly

(excluding bellows and stem assembly)

Bellows and stem assembly

Set of all gaskets

Set of bonnet studs and nuts (set of 4)

How to order spares

PN16 BS 10'F'

Weight

C

Scr.

Flg.

37

1.3

3.3

37

1.6

4.3

51

3.2

5.7

-

5.1

8.8

-

6.3

11.0

-

7.8

13.0

51

3.4

5.9

51

5.7

9.1

62

6.9

11.2

71

8.8

13.4

A, D, E, L

E, L

S

A, B, C, D, E

L, U, G

G, L, N, H

B, C, E, L, U, G

S

Size

DN15 - 1⁄2"

DN20-3⁄4"

DN25-1"

DN32-11⁄4"

DN40-11⁄2"

DN50 - 2"

KB31, KB33 and KC31

A

A1

A1

B

130 105

147 105

157 107

180 110

200 110

230 110

160

157

138

180

180

152

200

200

152

230

230

152

A1

90

130

104

150

136

160

144

180

150

200

180

230

Always order spares by using the description given in the column

headed 'Available spares' and state the size and type of valve.

Example: 1 - Valve seat assembly for a Spirax Sarco DN32 KB31

self-acting control valve.

DN25 - 1"

136

DN32-11⁄4" 144

DN40-11⁄2" 150

DN50 - 2"

180

(Flanged KA33 and KB33)

A

(Screwed KA31, KB31 and KC31)

E

D

C

U

A

B

X

H

G

N

L

S

KB31, KB33

and KC31

KA31 and KA33

C

B

A

Safety information, installation and maintenance

For full details see the Installation and Maintenance Instructions

(IM-S21-01) supplied with the product.

Installation note:

The valve should be fitted in a horizontal line with the actuator

vertically below the pipeline.

How to order

Example: 1 off Spirax Sarco 11⁄4" screwed BSP KA31 self-acting

control valve with cast iron body.

KA31, KA33, KB31, KB33 and KC31 Cast Iron Self-acting Control Valves

TI-P078-02 CH Issue 10

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4.5.22