36
Part No. 6-847703-00 Rev. C00
Operation
Gas Flow Through Manifold
Refer to Figures 22 and 23.
Gas is provided to left manifold bank inlet via
liquid cylinders and pigtails. Gas is provided to
right manifold bank inlet via high-pressure
cylinders and pigtails. Flow of gas through left
and right side of manifold is exactly the same,
each passing through a master valve and then
directly to a bank regulator. Liquid container (left
bank) or high-pressure cylinder (right bank)
pressure is applied to a normally open pressure
switch (closes when pressure is applied), and front
panel pressure gauge. Left bank liquid container
pressure is also applied to a 400 PSI relief valve.
Bank regulators reduce incoming container /
cylinder pressures to an intermediate pressure.
Bank regulators are referred to as a "dome
loaded" type of regulator. These regulators have
an internal adjusting spring that is manually set at
a specific pressure similar to other diaphragm type
pressure regulators. In addition to internal
adjusting spring, bias pressure may be applied to
dome of regulator (adjusting spring side of
diaphragm) thus boosting pressure above what is
manually set by adjusting spring. This output
pressure boost will be approximately equal to
amount of bias pressure.
For example, if a bank regulator is manually
adjusted to 70 PSI via internal adjusting spring,
and a dome bias pressure of 55 PSI is applied,
output pressure will increase to approximately 125
PSI (70 + 55). When bias pressure is removed,
output pressure setting will return to 70 PSI.
Outputs of both left and right bank regulators
each pass through check valves and connect
together upstream of a dual line regulator
assembly. An intermediate relief valve protects
components between bank and line regulators in
event of a bank regulator seat failure.
Dual line regulator assembly consists of two
line regulators plumbed in parallel with upstream
and downstream isolation 1/4-turn ball valves.
Output of both line regulators tee together and exit
at manifold's main outlet. A line relief valve and
line pressure gauge are connected to manifold's
main outlet.
Outlet pressure is routed to a dome regulator
reducing pressure to 40 PSI at solenoid valve.
Solenoid valve switches 40 PSI (dome bias
pressure) to one of bank regulators. When one
bank regulator is supplied bias pressure, other
bank regulator’s dome is vented to atmosphere.
An electronic circuit board controls solenoid valve
based upon input from right and left pressure
switches. Solenoid valve directs bias pressure to
“IN USE” bank.
Oxygen manifolds designed for 55 PSI nominal
output pressure do not incorporate a dome
regulator. Full line pressure (55 PSI) is routed
directly to solenoid valve and is used as dome
bias.
In addition to left and right liquid container /
high-pressure cylinder inlets, manifold is equipped
with an input from a high-pressure reserve header
assembly. This input is located on bottom of
manifold cabinet.
Refer to Figure 23 for high-pressure reserve
header assembly components.
Gas flows from high-pressure cylinders through
a master valve to a regulator, high-pressure gauge
and reserve low pressure switch. Regulator
output enters manifold, flows through a check
valve and into manifold piping just upstream of line
regulators.
