30 Questions
According to the text, which code provides guidelines for the layout of combustion safety components, especially those found on boilers?
CSA B149.3 code
Why does Figure 1 differ from other fuel trains shown in the PanGlobal Fourth Class text?
Due to changes in the fuel pressure and firing capacity
What is the purpose of CSA B149.3 Code mentioned in the text?
To provide guidelines for natural gas and propane burners installation
Which organizations mandate the existence of safety components for burner systems?
CSA and NFPA
In what scenarios does CSA B149.3 Code apply, according to the text?
For certified burners that are upgraded or modified
Why do fuel trains shown in the PanGlobal Fourth Class text differ from each other?
Due to changes in burner firing capacity
What is the purpose of preheating the fuel mentioned in the text?
To reduce the viscosity for proper atomization by the burner
Why is poor atomization of the fuel a concern?
It results in toxic and explosive carbon monoxide formation
What is the function of the low oil temperature cut-off?
To prevent the burner from starting when the fuel oil temperature falls below the recommended viscosity range
Why is it essential to supervise the atomizing media pressure for a steam or air atomized burner?
To avoid damage to refractory and heat transfer surfaces
What is the consequence of atomizing media pressure falling below the manufacturer’s design pressure for a steam or air atomized burner?
Safety shutdown and lockout
Why is it important for a fuel to be properly atomized by the burner?
To reduce the risk of incomplete combustion
What is the purpose of the fuel strainer (B) in the natural gas fuel train for boilers over 3000 kW output?
To catch debris before it affects the operation of fuel pressure regulators and control valves
What role do the pressure relief valves (D) serve in the natural gas fuel train for boilers over 3000 kW output?
To protect the pilot and main burner controls from excessive fuel pressure
Where should a low gas pressure safety device be installed for appliances with inputs in excess of 120 kW?
Downstream of the pressure regulator, upstream of the safety shut-off valve or valves, and upstream of the flow control valve
What is the purpose of a high gas pressure safety device according to CSA B149.3?
To initiate shut-off of the supply of gas when the gas pressure at the high gas pressure safety device exceeds 125% of the normal operating pressure at the maximum firing rate
What is a requirement for main fuel safety shut-off valves (SSOVs) according to CSA B149.3?
They must bear approval symbol CSA 6.5-2015 Automatic Valves for Gas Appliances
Where is a high gas pressure cut-off switch (HGPCO) typically located in a natural gas fuel train for boilers over 3000 kW output?
Just upstream of the input flow control valve
What is the purpose of the safety vent valve in a fuel train system?
To prevent fuel gas from leaking into the combustion chamber if the main SSOVs fail to close completely
Why are safety vent valves typically fast-acting and normally-open solenoid valves?
To ensure immediate reduction of fuel pressure to atmospheric if the main SSOVs fail to close
What is the function of the inlet flow control valve in a fuel train system with fully modulating burners?
To control the fuel flow based on load demand for different firing rates
Why is the firing rate control valve placed downstream of the low gas pressure cut-off switch?
To ensure that low gas pressure does not actuate at low firing rates
What is the purpose of test firing valves in a fuel train system?
To test the operation of flame detection devices and high fuel pressure cut-off
Why do pilot safety shut-off valves usually not have proof of closure according to the text?
Because they shut off a small fuel throughput compared to the main burner and do not require proof of closure
What is the purpose of fuel pressure test ports in a fuel train system?
To monitor and adjust the fuel pressure during burner operation
What unique components might be found in a fuel oil train that are not typically used in a fuel gas train?
Fuel filter, fuel pump, low oil temperature cut-off switch, and low atomizing media cut-off switch
What is the purpose of a fuel filter in an oil fuel train?
To protect oil burner nozzles from plugging due to suspended fuel contaminants
Why must oil trains have fuel pumps?
To provide necessary flow and pressure for proper atomization at maximum firing rate
What is the function of the low oil temperature cut-off switch?
To stop the flow of fuel to an oil burner that fires oil requiring preheating
What is the purpose of ASME CSD-1 Controls and Safety Devices for Automatically Fired Boilers mentioned in the text?
To provide guidelines for layout of combustion safety components especially on boilers
Test your knowledge of boiler safety systems with this quiz. Learn about the safety vent valve, proof-of-closure switches, and the potential risks associated with SSOV failure.
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