Line A ALL Flashcards
What is the main reason for performing combustion analysis on gas fired equipment?
To ensure the equipment is operating in a safe and efficient manner.
How often should your combustion analyser be calibrated to ensure accurate test readings?
Once per year.
Where should the sampling probe take a sample from on a gas fired appliance?
Upstream of any draft control device or just downstream of a stack economizer.
What is the correct way to allow combustion analysis samples to be taken with plastic S636 systems?
Installing an access tee with a ½” tapped bushing as close as possible to the flue collar of the appliance where either a plastic or brass plug can be inserted.
What is a Peltier cooler used for in a combustion analyzer?
To drive out moisture from the sample
The gas cells in a combustion analyser are of what type?
Electrochemical
What can shorten the life span of the toxic sensors in a combustion analyser?
High gas concentrations or insufficient purging
What is the chemical formula for the Perfect combustion of Natural Gas?
1CO2 + 2H2O = 8N2
What is the chemical formula for the Perfect combustion of Propane?
3C02 + 4H2O = 20N2
What is added to the combustion process to produce Complete combustion?
Excess Air
What is the expected percentage range of O2 produced by a forced draft burner with CH4 as the fuel?
3% - 6%
What are four characteristics of Carbon Monoxide?
Toxic, colourless, odourless and tasteless
What can cause too much draft in a venting system?
High stack temperatures
What percentage gain in efficiency is achieved by lowering stack temperature by 45⁰F?
Less than 1%
Calculate the net stack temperature if the ambient temperature is 72⁰F and the stack temperature is 420⁰F? Is this temperature within typically expected values?
348⁰F, Yes (330 - 500⁰F)
If the measure percent O2 reading is 4.1% and the measured NOx reading is 55 ppm, what would the NOx ppm be when corrected to standard?
58.58 ppm
If the measured CO reading is 38 ppm, and the measured %O2 reading is 4.2% what would the calculated air-free ppm reading be?
47.56 ppm
What is the power end of the Honeywell, Series 90 Modutrol used for?
It is used to drive linkages
What is the auxiliary end of the Honeywell, Series 90 Modutrol used for?
It is used to devices like auxiliary switches
In what orientation should motors with crankshafts be installed?
Horizontal
How is strain avoided on the motor and linkage of a fuel/air system?
The drive lever rotational start point is kept off of the shaft centerline
Fixed Stroke Actuators are available in what two opening ranges?
90⁰ or 160⁰
Adjustable stroke model actuators can be field adjusted between what range?
90⁰ - 160⁰
What controls the speed and the amount of rotation of the driven lever pivot point?
It is controlled by the starting position of both levers and the connection distance of the linkage to the lever pivot points
Placing the drive lever closer to the shaft centerline than the driven lever is placed will do what to the rotation of the driven lever?
It will be reduced
Placing the driven lever closer to the shaft centerline than the driver lever is placed will do what to the rotation of the driven lever?
It will be increased
How are precise changes made on the linkage for a fuel valve?
By adjusting the cam spring
The gas butterfly valve is used to control modulation and to stop gas flow?
TRUE / FALSE
FALSE, It is not used to stop gas flow
How can high and low fire be adjusted on a gas butterfly valve?
By using the stop screws
Where would you find information for making initial set up adjustments to linkages?
From the equipment manufacturer
What must be done while making any adjustments to linkages?
Combustion analysis must be performed
How do we balance safety and efficiency when adjusting our linkages with the use of a combustion analyzer?
- Adding more oxygen reduces the chance of CO and increases safety
- Reducing oxygen increases our efficiency but has the potential to increase CO thus being less safe.
- Always prioritize safety
