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Local regulations may restrict the use of this product to below the conditions quoted.In the interests of development and improvement of the product, we reserve the right to change the specification. Copyright 2005

ISO 9001

Cert. No. LRQ 0963008

TI-P019-02ST Issue 6

VB14 and VB21Vacuum Breakers

DescriptionThe VB14 is a small purpose designed vacuum breaker for generalpurpose applications on condensing vapour (steam) or liquid systems.

CertificationThis product is available with material certification to EN 10204 2.2for body and cap as standard.

Sizes and pipe connections" (system connection) screwed BSP or NPT.1" (air inlet connection) screwed BSP or NPT.

Pressure/temperature limits

VB14

Dimensions/weight (approximate) in mm and kgSize A B (A/F) C Kv Weight

" 55 34 34 0.52 0.35

Safety information, installation and maintenanceFor full details see the Installation and Maintenance Instructions(IM-P019-05) supplied with the product.

Installation note:The VB14 vacuum breaker must be installed in a vertical positionwith the system connection at the bottom. On steam systems, thevacuum breaker should be installed at the highest point in thesystem where it will not be flooded with condensate.

MaterialsNo. Part Material

1 Cap Brass CU ZN 39 PB2

2 Valve Stainless steel Z 100 CD 17

3 Valve seat Stainless steel Z15 CN 16 02

4 Body Brass CU ZN 39 PB2

5 Gasket Stainless steel AISI 304

Capacity Dp required to open vacuum breaker 4.6 mm Hg

How to orderExample: 1 off Spirax Sarco " VB14 vacuum breaker havingscrewed BSP connections.

1

2

5

3

4

25 30 40 50 100 200 300 400 5000.5

0.6

0.7

0.8

0.9

1

2

3

Flow

dm

3

/s

Dp (mm Hg)

Body design conditions PN16PMA Maximum allowable pressure 16 bar g @ 180C

TMA Maximum allowable temperature 260C @ 7 bar g

Minimum allowable temperature -196C

PMOMaximum operating pressure

14 bar gfor saturated steam service

TMO Maximum operating temperature 260C @ 7 bar g

Minimum operating temperature 0CNote: For lower operating temperatures consult Spirax Sarco.

Designed for a maximum cold hydraulic test pressure of 24 bar g

0

0

2 4 6 8 10 12 14 16

50

100

150

200

260

Temperature

C

Pressure bar g

The product must not be used in this region.

Steamsaturationcurve

Steamsaturationcurve

B

C

A

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400

300

200

100

0

0 5 10 15 20 25

VB14 and VB21 Vacuum Breakers TI-P019-02ST Issue 6

VB21DescriptionThe VB21 is a small purpose designed vacuum breaker for generalpurpose applications on condensing vapour (steam) or liquid systems.

CertificationThis product is available with material certification to EN 10204 2.2for body and cap as standard.

Sizes and pipe connections" (system connection) screwed BSP or NPT.1" (air inlet connection) screwed BSP or NPT.

Pressure/temperature limits

TemperatureC

Pressure bar g

Steamsaturationcurve

The product must not be used in this region.

Dimensions/weight (approximate) in mm and kgSize A B (A/F) C Kv Weight

" 52 36 36 0.52 0.33

Safety information, installation and maintenanceFor full details see the Installation and Maintenance Instructions(IM-P019-05) supplied with the product.

Installation note:The VB21 vacuum breaker must be installed in a vertical positionwith the system connection at the bottom. On steam systems, thevacuum breaker should be installed at the highest point in the

system where it will not be flooded with condensate.

MaterialsNo. Part Material

1 Cap Stainless steel AISI 303

2 Valve Stainless steel AISI 440 C

4 Body Stainless steel AISI 303

5 Gasket Stainless steel AISI 304

Capacity Dp required to open vacuum breaker 4.6 mm Hg

How to orderExample: 1 off Spirax Sarco " VB21 vacuum breaker having

screwed BSP connections.

1

5

2

4

B

C

B

25 30 40 50 100 200 300 400 500

0.5

0.6

0.7

0.8

0.9

1

2

3

Flow

dm

3/s

Dp (mm Hg)

Body design conditions PN25

PMA Maximum allowable pressure 25 bar g @ 120C

TMA Maximum allowable temperature 400C @13 bar g

Minimum allowable temperature -48C

PMOMaximum operating pressure

21 bar gfor saturated steam service

TMO Maximum operating temperature 400C @ 13 bar g

Minimum operating temperature 0CNote: For lower operating temperatures consult Spirax Sarco.

Designed for a maximum cold hydraulic test pressure of 38 bar g