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 configuration
A two way valve modulates from fully closed to fully open varying on the amount of hot water circulated through the heat exchanger to maintain the desired output temperature. When closed, the two way valve may cause a change in the heating water loop pressure, The two way valve will provide lower return temperatures to the boiler allowing the condensing boilers to condense, but varying flow rates back to the boiler.
Three way configuration
A three way valve modulates from directing all heating water through the heat exchanger to directing no heating water through the heat exchanger, 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. The return temperatures to the boiler will vary, but the return flow to the boiler will be constant.
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
(air) operated Control Valve
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.
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.
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.
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
U-Bend heating coil, rolled into copper lined tube sheet
CEMLINE manufactures a complete line of boiler water, steam, and high temperature hot water heating coils, which are constructed of copper or copper nickel or stainless steel tubing. The tube sheets for these coils are copper lined, and units provided with circulating pumps are designed with a copper wrapper surrounding the coil to provide an efficient means of providing the best heat transfer from the coil to the water to be heated. Recovery systems are quickly and efficiently sized to handle specific load requirements to meet any need.
Source Steam Pressure Gauge
easily readable pressure gauges to read both the source and generated
breaker will be mounted in the coil head and will break any
vacuum which might occur when the steam is condensed.
Electric Control System
Cemline elements are controlled by immersion thermostats adjustable to the desired temperatures and magnetic contactors. In our basic arrangement, the thermostat sensing bulbs are located at the various levels in the tank. As hot water is drawn out of the top of the heater, the level of cold water rises, turning on one thermostat at a time, which in turn energizes the contactors and elements in sequence. When the hot water consumption decreases, hot water accumulates in the tank from the top downward and the elements are in turn de-energized. Progressive engerizing and de-energizing of the heating elements in this manner balances the electric demand to hot water consumption. The element and heater load is normally divided into small increments which come on and go off in the manner described above. This means if a small amount of water is drawn from the tank only a small percentage of total load will come on to recover it. If, however, a large demand is experienced, a greater percentage of the load will come on to recover this usage. This system is extremely reliable, simple and automatic.
Cemline electric water heaters are equipped with magnetic contactors to close and open circuits as required for load control.
Cemline EHB Series heaters utilize "Class J" type fuses. Each contactor line is protected by an individual fuse, which is designed to interrupt power in the event of an overload condition.
Cemline EHB Series electric water heaters are factory wired, utilizing heat resistant, color coded copper wire. All components are factory wired to a generously sized terminal strip for solderless connections. Heaters furnished with circuit breaker or disconnect switch are factory wired to load side of breaker or switch.
Low Water Cut Off
Cemline electric units are furnished with electronic low water cut off, wired to open the control circuit on a low water condition.
Electric Control Cabinet
Cemline electric elements and controls are mounted in a NEMA 1 enclosure with a key lock door.
Final Assembly & Testing
Cemline packaged electric water heaters are thoroughly tested prior to shipment. All components and workmanship are guaranteed for a period of one year from dated of start-up or eighteen months from the date of shipment, which ever comes first.
Cemline electric water heaters are listed and labeled as required by Underwriters’ Laboratories
Double safety system
An optional safety system, which will deactivate the main control valve as described in solenoid safety system, will also activate a solenoid valve to drain excessively heated water. The controller is designed to permit different set points for the valve closure and draining.
Double wall brazed plate heat exchanger
Double wall brazed plate or plate and frame heat exchangers have inner and outer plates with a vented leak path. If either the inner or outer plate fails, no cross contamination of potable water is possible and a visible indication of the leak will show.
Solar Water U-Bend Heat Exchanger
A U-Bend heat exchanger can be provided for the solar water. Solar U-Bend heat exchanger coils are constructed of copper or copper nickel or stainless steel tubing. The tube sheets for these coils are copper lined. The U-Bend coil can be double walled tubing either copper inner/outer, 90:10 copper nickel inner / copper outer, or 90:10 CuNi inner / outer. The submerged tube bundle provides heat exchange between the solar water and the domestic water with the solar water inside the tubes and the domestic water on the outside of the tubes.
Boiler Water Pump
Cemline can provide as an option a thermostatically controlled boiler water pump. The pump will run when the when the domestic water temperature is below the controllers set point and the pump will turn off when the temperature setting has been satisfied. This pump will replace the modulating control valve and will be factory mounted.
Solar Water Pump
Cemline can provide a factory mounted solar water pump. The factory supplied solar controller that turns on/off this optionally supplied and mounted solar water pump based upon a differential between the tank temperature and the solar water temperature.