Spirax Sarco VB14 and VB21 are small, general-purpose vacuum breaker valves primarily used in condensate (steam) and liquid systems. Both are available with EN10204 2.2 certificates for the valve body and bonnet. For size and pipe connections, the system connections are ½” BSP threaded or NPT threaded, and the air inlet connections are 1/8” BSP threaded or NPT threaded. Both valves must be installed in a vertical position, with the system connection at the bottom. When used in steam systems, the vacuum breaker must be installed at the highest point of the system to prevent the valve from being submerged in condensate. For detailed safety information, installation, and maintenance instructions, refer to the Installation and Maintenance Guide (IM-P019-05) supplied with the product.

Spirax Sarco VB14 Vacuum Breaker

Operating Range

• Valve body design conditions: PN16

• PMA maximum allowable pressure: 16 bar g @180°C

• TMA maximum allowable temperature: 260°C@7 barg

• Minimum allowable temperature: -196°C

• PMO maximum saturated steam pressure: 14 bar g

• TMO maximum operating temperature: 260°C@7 barg

• Minimum operating temperature: 0°C

• Note: Consult Spirax Sarco for lower operating temperatures.

• Maximum design cold hydraulic test pressure: 24 bar g

Weight (approximate)

• Size ½”: 0.35 kg

Materials

No.	Component	Material
1	Cap	Brass (CU ZN 39 PB2)
2	Valve disc	Stainless steel (Z 100 CD 17)
3	Valve seat	Stainless steel (Z15 CN 16 02)
4	Valve body	Brass (CU ZN 39 PB2)
5	Washer	Stainless steel (AISI 304)

Capacity

The Δp required to open the vacuum breaker is 4.6mmHg.

Ordering Information

1-Spirax Sarco ½” VB14 vacuum breaker, BSP threaded connection.

Spirax Sarco VB21 Vacuum Breaker

Operating Range

• Valve body design conditions: PN25

• PMA maximum allowable pressure: 25 bar g 120°C

• TMA maximum allowable temperature: 400°C@ 13 bar g

• Minimum allowable temperature: -48°C

• PMO maximum saturated steam pressure: 21 bar g

• TMO maximum operating temperature: 400°C@ 13 bar g

• Minimum operating temperature: 0°C

• Note: Consult Spirax Sarco for lower operating temperatures.

• Maximum design cold hydraulic test pressure: 38 bar g

Weight (approximate)

• Size ½”: 0.33 kg

Materials

No.	Component	Material
1	Cap	Stainless steel (AISI 303)
2	Valve disc	Stainless steel (AISI 440C)
4	Valve body	Stainless steel (AISI 303)
5	Gasket	Stainless steel (AISI 304)

Capacity

The Δp required to open the vacuum breaker is 4.6mmHg.

Ordering Information

Example: 1-Spirax Sarco ½” VB21 vacuum breaker, BSP threaded connection.