Product Handbook 2026 - Volume 2

Pipeline ancillaries Vacuum breakers

10

VB21 and VB21 Food+

Sizes and pipe connections ½ "

(system connection) screwed BSP or NPT.

"

(air inlet connection) screwed BSP or NPT.

Pressure/temperature limits

Pressure psi g

0

72.5

145

218

290

363

752 572 392 212 32

Steam saturation curve

Pressure bar g

The product must not be used in this region.

Body design conditions

PN25

PMA Maximum allowable pressure

25 bar g @ 120 °C 363 psi g @ 248 °F

TMA Maximum allowable temperature

400 °C @13 bar g

752 °F @ 189 psi g

Minimum allowable temperature

-48 °C

-54.4 °F

PMO Maximum operating pressure for saturated steam service

21 bar g

305 psi g

TMO Maximum operating temperature

400 °C @ 13 bar g

752 °F @ 189 psi g

Minimum operating temperature

0 °C

32 °F

Note: For lower operating temperatures consult Spirax Sarco Designed for a maximum cold hydraulic test pressure of:

38 bar g

551 psi g

Capacity D p required to open vacuum breaker 4.6 mm Hg (0.2 in Hg)

∆p (in Hg)

1 1.2 1.6 2

4

8

12 16 20

6.4

10.12 5

4.2

2.1 1.9 1.7 1.5 1.3 1.1

D p (mm Hg)

TI-P019-02 CMGT Issue 12

Page 5 of 6

VB14, VB21 and VB21 Food+ Vacuum Breakers

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