Product Handbook 2026 - Volume 1

Control systems Control valves

4

Q series control valve selection guide:

DN15 and DN20 (mixing service only)

Valve size

DN25

DN25, DN32, DN40, DN50, DN65, DN80, DN100, DN120, DN150 and DN200 (mixing and diverting service)

Valve series

Q

Q = Q series 3-port

Valve characteristic

L

L = Linear

3 = Cast iron

4 = Carbon steel 6 = Stainless steel 7 = SG iron

Body material

4

Connections

3

3 = Flanged

D = Diverting

3-port design

M

M = Mixing

Blank = Standard PTFE chevron H = Graphite packing

Stem sealing

B1 = PN16 bellows seal B2 = PN25 bellows seal

4.1 121

Blank = Standard metal-to-metal W = Hard facing (stellite) G = Soft seal (PTFE)

Seating option

Blank = Standard

Other options

X = Extended bonnet

Flow coefficient

Kv10

To be specified

Connection type

PN40

To be specified

Selection example: DN25 Q L

4

3

M

Kv10

PN40

How to order Example: 1 off Spirax Sarco DN25 QL43M Kv10 flanged to PN40.

TI-P359-14 CTLS Issue 8

Page 9 of 11

QLM and QLD Three-port Control Valves

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