Type Y696
3
chemicals, or other foreign material, point the vent down
or otherwise protect it.
4. To remotely vent the regulator, remove the vent
(key 56) and install obstruction-free tubing or piping into
the 1/4-inch NPT vent tapping. Provide protection on a
remote vent by installing a screened vent cap into the
remote end of the vent pipe.
5. If continuous operation of the system is required
during inspection or maintenance, install a three-valve
bypass around the regulator.
6. Vapor recovery regulators are used to maintain a
constant inlet (blanket) pressure with the outlet flowing
to a system whose pressure is lower than that at the
inlet. The vapor recovery regulators are not intended to
be used as an ASME certified relief device for overpres-
sure protection. They are to be used as part of a gas
blanketing system to control the outflow of blanketing
gas under normal conditions and to collect tank vapors
for the vapor disposal or reclamation system. You
should provide alternate methods of emergency over-
pressure protection.
Startup and Adjustment
To avoid personal injury, property dam-
age, or equipment damage caused by
bursting of pressure containing parts or
explosion of accumulated gas, never
adjust the control spring to produce an
outlet pressure higher than the upper
limit of the outlet pressure range of that
particular spring. If the desired outlet
pressure is not within the range of the
control spring, install a spring of the
proper range according to the dia-
phragm and spring case area section of
the maintenance procedure.
With installation completed, the regulator can be placed
in operation by slowly opening the upstream and
downstream block valves, if used, while using gauges to
monitor pressure.
The regulator has been adjusted at the factory to
provide approximately the pressure requested. The
range of allowable pressure settings is stamped on the
spring casing nameplate. If a pressure setting beyond
the stamped range is required, install a spring with the
desired range by following the procedures for changing
Figure 2. Operational Schematic
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
E0751
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
Figure 3. Principal of Operational Schematic
LIQUID
VAPOR PRESSURE
VAPOR RECOVERY
VACUUM SOURCE
