Fuel Burning System; Fuel Train; Control Panel - Lattner Boiler Company H.E. Instruction Manual

1. Relief Valve
In compliance with the ASME Code, a steam boiler
pressure relief valve is provided. Size and quantity are
determined by the valve setting, valve capacity, and the
ASME Code. Valve may be shipped loose to prevent
possible damage during shipment.
2. Water Column
Factory mounted and piped complete with gauge glass,
gauge glass drain valve, gauge glass isolation valves,
column drain valve, and a minimum of 1" equalized
piping and crosses for inspection and clean-out.
3. Low Water Cut-Off
To prevent burner operation whenever a low water
condition occurs, an electronic probe-sensing device, or
float operated control is furnished in the water column.
This device is wired in series to the burner combustion
safeguard control to prevent burner operation whenever
a low water condition occurs.
4. Pump Control
When a probe sensing main level control is furnished,
two stainless steel probes are furnished in the water
column to provide pump ON/OFF operation for water
make-up. These probes are wired to an electronic
interlock relay for pump or water valve control. However,
if the column is a float-actuated device, a snap acting
single pole single throw switch activates a pump
contactor for ON/OFF pump or solenoid valve operation.
5. Auxiliary Low Water Cut-Off
An additional control, separate from the primary low
water control is provided to prevent burner operation if a
low-low water condition exists. This device is an internal
probe control located on the side of the pressure vessel,
and requires manual reset whenever a low water
condition occurs.
6. Steam Pressure Gauge
A 3-1/2" dial pressure gauge is furnished as standard.
The range of the gauge will be in accordance with the
safety valve setting, based on 1.5 times the valve setting
for high-pressure units, and two times the design
pressure of low-pressure units.
7. Steam Pressure Controls
At least two controls are furnished with each boiler: One
for ON/OFF operation (controller) and one for preventing
burner operation if excess steam pressure is sensed
(limit). The limit control is a manual reset control.
8. Valves
Standard valve piping package consists of one (1)
feedwater stop valve, one (1) quick open bottom
blowdown valve, and one (1) slow open blowdown valve.
D. Fuel Burning System
The boiler is furnished with a UL approved atmospheric draft
burner system. This system is mounted and wired integral
with the front centerline of the boiler.
1. Burner Type
The atmospheric draft burner is designed for Natural or
LP gas only.
2. Burner Operation
The burner is designed to operate in an ON/OFF mode.
3. Ignition/Pilot
Gas fired units are equipped with either a thermocouple
pilot (standing) or spark ignited (intermittent) pilot
assembly.
4. Atmospheric Burners
HE boilers include sheet metal atmospheric burners.
5. Fuel/Air Control
The control of combustion air is managed by adjusting
the air shutter on each sheet metal burner and gas
valve supplied with the gas train (gas inlet pressure and
volume).
E.

Fuel Train

The burner is equipped with factory mounted fuel safety
control and safety shutoff valves. Each fuel piping assembly
is equipped with the following:
1. Gas Assembly
Gas train is a piped and wired assembly, consisting of
main gas pressure regulator, safety shutoff valve(s),
manual shutoff cock(s), in accordance with the latest UL
and CSD-1 requirements. Main gas valve may also
function as the main gas pressure regulator.
F.

Control Panel

A NEMA 1A enclosed (powder coated finish) control panel is
mounted integral to the burner or on an independent bracket
mounted on the boiler. This panel contains following
components:
1. Boiler ON/OFF Switch
Provided to interrupt control power to the 120 volt
control circuit. Does not disconnect the main power
source.
2. Pump ON/OFF Switch
Provided to isolate the pump control circuit.
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