299H Series
7
if this regulator is overpressured or is
installed where service conditions could
exceed the limits for which the regulator
was designed 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
standard) to prevent service conditions
from exceeding those limits.
A regulator may vent some gas to the
atmosphere in hazardous or flammable
gas service. Vented gas might accumulate
and cause personal injury, death or
property damage due to fire or explosion.
Vent a regulator in hazardous gas service
to a remote, safe location away from air
intakes or any hazardous location. Protect
the vent line or stack opening against
condensation or clogging.
If the regulator is exposed to an
overpressure condition, it should be
inspected for any damage that may have
occurred. Operation below these limits
does not preclude the possibility of
damage from external sources or from
debris in the pipeline.
If the Type VSX-2 is exposed to an
overpressure condition, it should be
inspected for any damage that may have
occurred. Operation below these limits
does not preclude the possibility of
damage from external sources or from
debris in the pipeline.
In the case of a downstream line break,
numerous factors affect the capability
to evacuate gas from the pipeline.
These factors include the distance of
pipe to the break, the diameter of the
pipe, size of the break and the number
of restrictions, such as valves, elbows
and bends, downstream of the regulator
and/or slam-shut device. Due to these
factors additional protections should be
installed to stop flow in the event of a
line break.
Like most regulators, the 299H Series regulators have
an outlet pressure rating lower than its inlet pressure
rating. Complete downstream overpressure protection
is needed if the actual inlet pressure can exceed the
regulator outlet pressure rating or the pressure ratings
of any downstream equipment. Regulator operation
within ratings does not preclude the possibility of
damage from external sources or from debris in the
lines. A regulator should be inspected for damage
periodically and after any overpressure condition.
Clean out all pipelines before installation. Check for
damage which might have occurred during shipment.
Also, check for and remove any dirt or foreign material
which may have accumulated in the regulator body.
Apply pipe compound to the external pipe threads of
threaded bodies or use suitable line gaskets and good
bolting practices with a flanged body. This regulator
may be installed in any position desired as long as the
flow through the body is in the direction indicated by the
arrow on the body. Install a three-valve bypass around
the regulator if continuous operation is necessary during
maintenance or inspection.
Although the standard orientation of the actuator and
pilot to the main valve body is as shown in Figure 1,
this orientation may be changed in 90° intervals by
rotating the actuator lower casing (key 1, Figure 6) and
the elbow fitting (key 19) by 90° and then reinstalling
the cap screws.
To keep the pilot spring case from being plugged or the
spring case from collecting moisture, corrosive chemicals
or other foreign material, the vent must be pointed down
oriented to the lowest possible point on the spring case
or otherwise protected. Vent orientation may be changed
by rotating the pilot spring case with respect to the
pilot body.
To remotely vent the pilot, remove the screwed-in vent
assembly (key 27, Figure 5) from the pilot spring case
and install obstruction-free tubing or piping into the
1/4 NPT vent tapping. Provide protection on a remote
vent by installing a screened vent cap into the remote
end of the vent pipe.
An upstream pilot supply line is not required
because of the integral pilot supply tubing (key 21,
Figure 6). However, as long as the 1/4 NPT tapping
in the main valve body is plugged, this tubing may
be disconnected from the main valve (key 17) in
order to install a pilot supply line from a desired
remote location into the pilot.
If using a control line, attach the control line from the
pilot tap 2 to 3 feet / 0.61 to 0.91 meters downstream
of the regulator in a straight run of pipe. If impossible
to comply with this recommendation due to the pipe
arrangement, it may be better to make the control line
tap nearer the regulator outlet rather than downstream
of a block valve. Do not make the tap near any elbow,
swage or nipple which might cause turbulence. For
optimal performance, use as large of a control line
as practical.
