
There are some guidelines for the proper installation of
gas regulators. These brief guidelines are in no way meant to
be a substitution for the Manufacturer's Installation and Maintenance
Instructions may have specific details that pertain to each
model. With the installation of ALL regulators it is advisable
to install a pressure gauge locally at the inlet and outlet
of the regulator along with gauge petcocks to manually isolate
each gauge. These gauges are necessary to monitor the performance
and field set the regulator.
First, we must differentiate between two styles of regulators
as it impacts their orientation:
| Direct Acting Type
You can tell if you have a Direct Acting
regulator if the axis of the spring chamber intersects
with the valve body of the regulator. This type of regulator
MUST be installed in horizontal run with diaphragm horizontal
above the pipe run. On extremely low pressure applications,
the diaphragm can sometimes be installed below the pipe
to eliminate forces due to the weight of the diaphragm,
consult BD USA directly in these cases. Make sure the
installation is accessible, and the vent line is properly
installed.
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Lever Operated
Type
You can tell a Lever Operated regulator by noting that
the spring chamber axis never intersects the valve's
body. The axis of the spring chamber and the diaphragm
assembly are connected to the valve stem via a "lever".
This regulator can be installed in any position, vertical
or horizontal, provided the venting is done properly
and the regulator is accessible
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Pipe Runs, Inlets & Outlets
In order to provide the regulator with the ability to function
properly, install it in a region of developed flow where the
flow profile will not be disrupted. On the inlet and outlet,
whenever possible provide for 5 to 10 pipe diameters of straight
pipe without throttling devices or other components and fittings
that will disrupt flow. These disruptions make the regulators
job more difficult and sometimes unable to function properly.
External Sensing Lines
A vast majority of "common" regulators, especially
the smaller ones, are internally sensed, meaning the under
side of the diaphragm is sensing pressure internal to the
regulator's body just downstream of the valve & seat arrangement.
This would be the pressure at the outlet of the valve after
it has been adjusted by the regulator. On the other hand,
if you are dealing with a regulator with an external sensing
line, locate the remote sensing downstream of the regulator
8 to 10 pipe diameters of straight pipe run in the largest
diameter piping present. The start of 8 to 10 pipe runs is
after the transition to the largest diameter pipe or any other
throttling devices, component and/or fittings that will disrupt
flow and create turbulence. The sensing line should be taken
off the top of the main line so to keep it free of debris
and condensate. If possible, it should horizontally slope
back to the main so that any condensate that may form will
drain back into the main rather than accumulate in the regulator's
diaphragm. If a manual valve is installed in the sensing line,
it is recommended to lock this valve in the open position
so that someone does not mistakenly isolate the sensing tap
from the regulator. Minimize the fittings used in running
the sensing line. The regulator will response to the pressure
changes sensed at the remote tap rather than on the outlet
of the valve and seat. It is advisable to install a petcock
and pressure gauge at the sensing line tap on the main as
this will be the control point of the regulator.
Vent Lines
Venting requirements and codes vary from County to County,
State to State. Always follow local code requirements in venting
regulators. Vents not only provide a leak path for gas when
a diaphragm ruptures but also allows the diaphragm to "breathe"
and function properly. If a vent is restricted a regulator's
performance will be adversely effected and tend to "hunt"
or not properly control the pressure. Do not use excessive
long runs or amounts of fittings in plumbing vent lines. If
piping becomes excessive due to physical limitations of the
jobsite, bush to the next size up of pipe to increase the
stack effect and reduce frictional losses. Never reduce the
vent piping size from that of the connection on the regulator.
Always turn outlet of the vent line downward so as to limit
the effects of outdoor weather and debris. Install a bug screen
on the vent outlet to prevent insects from nesting in the
line. Insure that bug screens are not painted over. In venting
to a roof in an area that commonly gets winter snow fall,
make sure the vent discharge is sufficiently above the roof
line to account for a snow layer on the roof. Always insure
venting is done in a safe area, away from any fresh air intakes,
windows, and people. When venting propane, take extra care
to insure no pockets of gas can collect in low-lying areas,
REMEMBER, propane falls to the ground, and natural gas floats
away!
Please feel free to contact your
Local Bryan Donkin Distributor or call 866-4 MY REGS for additional
support.
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