Fisher CS403 Instruction Manual page 9

The CS400 Series regulators have an
outlet pressure rating lower than their
inlet pressure rating. If actual inlet
pressure can exceed the outlet pressure
rating, outlet overpressure protection
is necessary. However, overpressuring
any portion of the regulators beyond
the limits in Specifications section may
cause leakage, damage to regulator
parts or personal injury due to bursting
of pressure-containing parts.
Some type of external overpressure
protection should be provided to the
CS400 Series if inlet pressure will be
high enough to damage downstream
equipment. Common methods of
external overpressure protection include
relief valves, monitoring regulators, shut
off devices and series regulation.
If the regulator is exposed to an
overpressure condition, it should be
inspected for any damage that may
have occurred. Regulator operation
below these limits does not preclude
the possibility of damage from external
sources or from debris in the pipeline.
General Installation Instructions
Before installing the regulator,
• Check for damage, which might have occurred
during shipment.
• Check for and remove any dirt or foreign material,
which may have accumulated in the regulator body.
• Blow out any debris, dirt or copper sulfate in the
copper tubing and the pipeline.
• Apply pipe compound to the male threads of the
pipe before installing the regulator.
• Make sure gas flow through the regulator is in the
same direction as the arrow on the body. "Inlet"
and "Outlet" connections are clearly marked.
• When designing a pressure reducing station using
a CS400 Series regulator, make an analysis if it is
necessary to take into account the effects of wind,
snow and temperature to avoid unnecessary load
and movement to the flanges of the equipment.
CAUTION
• If needed, a support may be used under the piping
and regulator/slam-shut body to avoid excessive
pressure force on the regulator/slam shut.
Installation Location
• The installed regulator should be adequately
protected from vehicular traffic and damage from
other external sources.
• Install the regulator with the vent pointed
vertically down, see Figures 5 through 7. If
the vent cannot be installed in a vertically down
position, the regulator must be installed under a
separate protective cover. Installing the regulator
with the vent down allows condensation to drain,
minimizes the entry of water or other debris from
entering the vent and minimizes vent blockage
from freezing precipitation.
• Do not install the Types CS400, CS403 or CS404
in a location where there can be excessive
water accumulation or ice formation, such as
directly beneath a downspout, gutter or roof line of
building. Even a protective hood may not provide
adequate protection in these instances.
• Install the Regulator so that any gas discharge
through the vent or vent assembly is over 3 ft /
0.91 meters away from any building opening.
Regulators Subjected to Heavy
Snow Conditions
Some installations, such as in areas with heavy
snowfall, may require a hood or enclosure to protect
the regulator from snow load and vent freeze over.
Downstream Control Line Installation
A CS400 Series regulator with an EN or ET in the
type number has a blocked throat, an O-ring stem
seal and a 3/4 NPT control line tapping in the lower
diaphragm casing. A regulator with a downstream
control line is used for monitoring installations or
other applications where there is other equipment
installed between the regulator and the pressure
control point.
For Types CS400ET and CS400EN regulators,
connect downstream control line tubing to the lower
casing and run the tubing approximately 20 in. /
508 mm downstream. For best results, the outer
diameter of the control line tubing should be 3/8 in. /
9.5 mm or larger.
CS400 Series
9