February 1999
Y690VB Series
Instruction Manual
Form 5465
D102594X012
www.FISHERregulators.com
Y690VB Series Vacuum Breakers
Introduction
Scope of Manual
This manual describes and provides instructions and
parts lists for the Type Y690VB and the Type Y690VBM
vacuum breakers. Instructions and parts lists for other
equipment used with these breakers are found in
separate manuals.
Product Description
The Y690VB Series vacuum breakers are used for
precise control of small capacity, low-pressure service
applications where an increase in vacuum must be
limited. These direct-operated vacuum breakers come
in 3/4 (DN 20) and 1-inch (DN 25) body sizes and have
a 1/4-inch (6,4 mm) or 1/2-inch (12,7 mm) orifice. The
individual products are described as follows:
Type Y690VB
The Type Y690VB is a vacuum breaker with internal
pressure registration requiring no downstream
control line.
Installation
Personal injury, property damage, equip-
ment damage, or leakage due to escaping
gas or bursting of pressure-containing
parts may result if this equipment is over-
pressured or is installed where service
conditions could exceed the limits given in
table 1, or where conditions exceed any
ratings of the adjacent piping or piping
connections. To avoid such injury or
damage, provide pressure-relieving or
pressure-limiting devices (as required by
the appropriate code, regulation, or stan-
dard) to prevent service conditions from
exceeding those limits. Additionally,
physical damage to this equipment could
cause personal injury or property damage
due to escaping gas. To avoid such injury
or damage, install the equipment in a safe
and well ventilated location.
Equipment operation within ratings does not preclude
the possibility of damage from debris in the lines or
from external sources. This equipment should be
inspected for damage periodically and after any over-
pressure condition.
WARNING
!!!!!
Figure 1. Type Y690VB Vacuum Breaker
W7292
Type Y690VBM
The Type Y690VBM is a vacuum breaker with a control
line connection and a throat seal for external pressure
registration.
Specifications
Table 1 gives some general ratings and specifications
for the Y690VB Series vacuum breakers. Individual
breakers come from the factory with the specific data
stamped on the nameplate.
