VACUUM BREAKER INSTALLATION
Figure 1 – Standard Vertical Installation
Pipe as shown if possible for a preventative measure. If the outlet is exposed it can become fouled
with dust and dirt. Upon operation this contamination can prevent the vacuum breaker from
resealing.
Figure 2 – High Temperature or Hazardous Chemical Service
Pipe as shown for safety reasons. After undeterminable amount of time the vacuum breaker will fail.
Having the outlet piped to a safe location eliminates a safety hazard. Although the installation
shown is vertical with outlet on the bottom, this should be done regardless of the installation
orientation.
Figure 3 – High Temperature Installation
Piping the vacuum breaker as shown can eliminate the need for special high temperature seals.
The temperature at the vacuum breaker varies depending the steam line temperature. The pigtail
should be sized to have a flow area equal or greater than that of the vacuum breaker used.
Figure 4 - Engaged Length
When piping in the vacuum breaker, attention should be given to the engaged length ”E”.
1. The vacuum breaker should never be installed such that the screen is in the flow path. In
instances of high velocities the correct operation can be disrupted as well as damage to the
vacuum breaker.
2. Vacuum breakers should be installed in pipe couplings to prevent damage on installation.
An example of this would be installation in the short side of a pipe tee where the screen
could be crushed.
THE JOHNSON CORPORATION
805 Wood Street, Three Rivers, Michigan 49093 USA
tel: 616.278.1715 fax: 616.279.5980
www.joco.com
Vacuum Breakers - page 2
Dimensions are in inches and for reference only.
Certified drawings are available on request.
VACUUM BREAKERS
Typical Installations of Johnson Vacuum Breakers
Johnson Vacuum Breaker installed on heating coil. When the modulating
control valve closes, the steam in the coil will condense. Actually, a vacuum
can exist in the coil with the control valve partly open and positive pressure
between the control valve and the coil.
HEATING COIL
MODULATING
CONTROL VALVE
JOHNSON
VACUUM BREAKER
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