STEAM
STANDARD
EQUIPMENT
CONTROL
VALVE
Pilot
Operated
A pilot operated valve can only be used with steam as the energy source.
Pilot operated valves use steam pressure as the energy source to modulate
the control valve. Steam from upstream of the valve is directed into
a pilot valve. This pilot valve has an adjustable set point and temperature
sensing bulb in the heated water. The pilot valve compares the set
point to the sensed temperature and regulates the amount of steam
passing through the pilot to the diaphragm in the bottom of the control
valve.The steam pressure on the diaphragm opens to the downstream
side of the valve. When the pilot valve senses the desire temperature
is reached it closes; this does not allow any more steam to pressurize
the diaphragm in the bottom of the control valve. The bleed line allows
any steam pressurizing the diaphragm to be relieved and the valve
closes.
In the event of high temperature or loss of building power the limit
control closes the steam line from the pilot to the control valve
which closes the valve. With a supply pressure of up to 15 PSI, 3
PSI is the minimum pressure drop permitted.
Pneumatic
(air) operated Control Valve
ir operated
valves use building control air pressure to modulate the control
valve. The air signal is brought to an adjustable set point temperature
sensing controller with a temperature sensing bulb in the heated
water. The temperature sensing controller compares the set point
to the sensed temperature. The controller regulates the amount
of air that passes to the pneumatic actuator of the valve to modulate
the valve. This allows steam to pass into the heater coil to maintain
the set point of the controller. When the set point is achieved,
no air is passed through the temperature sensing controller and
the valve is closed. In the event of high temperature or loss
of building power, the limit control shall close the air line
to the valve and vent any air in the actuator to atmosphere which
closes the valve.
Electronic
Control Valve
Electronically operated
control valves use a solid state temperature sensor which
is wired to an electronic control module. The electronic control
module has an adjustable set point. The control module compares
the set point with the sensed temperature and sends an
electric signal to a magnetic linear actuator on the control valve.
The magnetic linear actuator modulates the control valve and
regulates the amount of boiler water through the valve to maintain
the set point of the controller. When the set point is
achieved, the controller sends a signal to the valve actuator and
the valve closes. In the event of high temperature loss or loss
of building power, the limit control closes the electric power
to the controller which closes the valve.
Steam Traps
CEMLINE provides
float and thermostatic traps for both the drip and main trap. Float
and thermostatic traps are acknowledged as the correct traps to use
with continuously modulating control valves. Float and thermostatic
traps provide immediate drainage of condensate and include a built in
thermostatic air vent for venting air. The drain orifice is designed
to provide a water seal and eliminate the loss of any live steam under
all load conditions. Float and thermostatic traps should not be used
to lift condensate.
Inlet Stream Strainer
Strainers are "Y"
type with blow down connection and easily removable stainless steel
strainer screen.
Source Steam Pressure Gauge
Large,
easily readable pressure gauges to read both the source and generated
steam pressure.
Vacuum breaker
A vacuum
breaker will be mounted in the coil head and will break any
vacuum which might occur when the steam is condensed.
Double solenoid safety system
An
optional safety system, which will deactivate the main control
valve as described in solenoid safety system, will also activate
a second solenoid valve to drain excessively heated water. The
controller is designed to permit different set points for the
valve closure and draining.
Double wall coil
Double wall coils have inner and outer tubes
with a vented leak path. If either the inner or outer
tube fails, no cross contamination of potable water is possible and a visible
indication of the leak will show. Double wall coils are
only available in 3/4" OD tubing.
BOILER
WATER
STANDARD
EQUIPMENT
CONTROL
VALVE
Pneumatic (air) operated Control Valve
An air operated
valve can be used with hot water as the heating medium. Air operated
valves use building control air pressure to modulate the control valve.
The air signal is brought to an adjustable set point temperature sensing
controller with a temperature sensing bulb in the heated water. The
temperature sensing controller compares the set point to the sensed
temperature. The controller regulates the amount of air that passes
to the pneumatic actuator of the valve to modulate the valve. This
allows boiler water to pass into the heater coil to maintain the set
point of the controller. When the set point is achieved, no air is
passed through the temperature sensing controller and the valve is
closed. In the event of high temperature or loss of building power,
the limit control shall close the air line to the valve and vent any
air in the actuator to atmosphere which closes the valve.
Electronic Control Valve
Electronically
operated control valves use a solid state temperature sensor which
is wired to an electronic control module. The electronic control module
has an adjustable set point. The control module compares the set point
with the sensed temperature and sends an electric signal to a magnetic
linear actuator on the control valve. The magnetic linear actuator
modulates the control valve and regulates the amount of boiler water
through the valve to maintain the set point of the controller. When
the set point is achieved, the controller sends a signal to the valve
actuator and the valve closes. In the event of high temperature or
loss of building power, the limit control closes the electric power
to the controller which closes the valve.
Two way Valve
A two way valve
modulates from fully closed to fully open varying the amount of hot
water circulated through the coil to maintain the desired output temperature.
When closed the two way valve may cause a change in the heating water
loop pressure.
Three way valve
A three way valve
modulates from directing all heating water through the coil to directing
no heating water through the coil, varying the amount of hot water circulated
through the coil to maintain the desired output temperature. The pressure
drop in the heating system will be relatively constant with a three
way valve.
OPTIONAL
EQUIPMENT
Double solenoid safety system
An optional safety system, which will deactivate the main control valve
as described in solenoid safety system, will also activate a second solenoid valve
to drain excessively heated water from the heater. The controller is
designed to permit different set points for the valve closure and draining.
Double wall coil
Double wall coils have inner and outer tubes with a
vented leak path. If either the inner or outer tube fails, no cross contamination of
potable water is possible and a visible indication of the leak will show. Double
wall coils are only available in 3/4" OD tubing.
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