Brochure

7
Mixing
This arrangement allows for constant flow through the
system. The valve is modulating, and determines how
much water is flowing through the coil, and how much
water is bypassing the coil. The flow is constant.
Note: the normally closed port is indicated by the
darkened triangle.
In the top example, the valve is in the stem up position
and flow is closed to the coil. The water is being
bypassed around the coil. In the bottom example,
the valve is stem down and the bottom port is closed.
The flow is through the coil and not through the bypass.
When looking at two way piping, go from left to right.
Typically, there’s an a isolation valve on each end of the
system. Next, is a strainer to remove particulate, such as
rust or corrosion. The heating/cooling coil is for air/water
heat exchange and a balancing valve equalizes the water
flow through the various branches of the system. The
control valve and actuator are next in the system and
regulates flow through the coil.
In these systems, normally open/normally closed is relevant
with a spring return,or fail-safe type actuator. When power
fails, the actuator will position the valve in the normal
position. The top example is closed with no flow.
Note that the normally closed valve is indicated by the
darkened inlet port. The bottom example is normally open,
with flow for heating and cooling during power failure.
Other arrangements are possible, for example, the valve
could be located on the inlet side of the coil. The best place
to put the control valve is after the coil, which allows the
pressure drop first through the coil, and also extracts the
heating or cooling energy from the media, before passing
through the valve.
Isolation Valve Isolation ValveStrainer Coil
Balancing
Valve
Control
Valve
Normally
Closed
Valve
Isolation Valve Isolation ValveStrainer Coil
Balancing
Valve
Control
Valve
Normally
Open
Valve
How valves work
Diverting
In a typical piping arrangement, for 3-way valves in a
diverting application, the valve is on the front side of
the coil.
The functionality and flow through the coil is
the same in this diverting configuration as in the
mixing configuration on the left. The only difference
is the location of the valve, relative to the coil.
2-Way piping
3-Way piping
Isolation Valve Isolation ValveStrainer Coil
Balancing
Valve
Control
Valve
Stem Up
Isolation Valve Isolation ValveStrainer Coil
Balancing
Valve
Control
Valve
Stem Down
Isolation Valve Isolation ValveStrainer Coil
Balancing
Valve
Control
Valve
Isolation Valve Isolation ValveStrainer Coil
Balancing
Valve
Control
Valve
Stem Up
Stem Down