Liquefied Petroleum Systems ( LP ) Flashcards
Compression fittings are not______.
Permitted
Steel fittings must be_____.
Zinc coated
Brass fittings must be ________.
Forged
Pipe fittings must be _______.
Black iron
Black iron pipe should be ______.
•Schedule 40 for vapor
• Schedule 80 for liquid.
What is the function of a regulator?
• Reduces variable high pressure to a usable working pressure
• First stage reduces container pressure to 10psi
• Second stage reduces first stage pressure to a working pressure.
The main regulator must be mounted with the vent _____ degrees from horizontal.
45°
What should not be attached directly to the propane cylinder shut off valve valve?
Regulators
The CSA Z240 code book requires that the regulatory shall be protected by a ____ or ____ cover.
Metal or plastic cover
What is the system working pressure?
11 inches WC
WC= Water Column
Measured with a manometer
What is the maximum allowed static pressure?
14 inches WC
WC=Water Column
Regular first stage reduces tank pressure to approximately what PSI?
10PSI
Second stage reduces the pressure to _____ water column.
11 inches WC
Appliance regulators are set at ______
10-10.5” WC
Dial type manometers should be regularly calibrated by a ______.
U-tube manometer
RV systems are adjusted to ______ water column.
Inches
What does a manometer do?
Measures pressure in inches of water column
What do technicians use manometers for?
To correctly adjust the main regulator pressure and leak test system.
Regulators must be mounted with the vent _______ from horizontal.
45° or more from horizontal.
CSA Z240 code book requires that an auto change over regulator must be installed if _____.
The service and reserve cylinders are mounted on the RV.
CSA Z240 states that the main regulator must be of the _____ complying to UL standards.
2 stage type.
Using a 2 stage, regulator enables more consistent control of the______.
Working pressure
Propane vapor pushes against a diaphragm that acts against atmospheric what?
Pressure and a Spring.
As the diaphragm moves up-and-down, it controls a lever that opens and closes a valve to______.
Regulate the propane system pressure.
What happens if either atmospheric pressure or spring pressure increases?
The system pressure will increase because it takes more propane pressure, to overcome the different pressure and close the valve.
What will reducing atmospheric or spring pressure do?
It will decrease system pressure because of the reduced force required to close the valve.
An automatic change over regulator is a 2 stage regulator designed to be used with what?
Two propane cylinders.
Both cylinder valves should be _____ when using an auto change over regulator.
Open
Steps for a leak test using automatic change over regulator.
1) Ensure all appliances are turned off.
2) Open the service cylinder to pressure the system and then close it.
3) The indicator should stay green if no leaks are present.
4) Wait 10 minutes and recheck to ensure the indicator does not change to red.
( Change to red would mean a loss of pressure indicating a leak.)
What equipment do you need to conduct a leak test and identify the leak location?
An electronic leak detector or leak detection fluid.
What is added to propane to produce a rotten egg smell?
Ethyl Mercaton is added at 0.48%.
What WHMIS symbols are found on large propanes cylinders.
Propane is a bi-product of?
Petroleum refining and natural gas processing.
Propane expands in volume at a rate of ______.
270 times when changing from a liquid to a vapor.
What does OPD Stand for?
Overfill safety device.
Propane is _________.
Non corrosive
ASME Tanks are inspected every_____ years
5 years
TC cylinders are recertified every ______ years.
10 years
Cylinders must be mounted to withstand _____ their loaded mass.
8x
Why do we have to purge?
To get rid of contaminants.
What should you never vacuum purge?
A used container.
What increases the “wetted surface” and can help with vaporization in cold weather?
Full containers, which is 80% capacity.
What should you always purge with?
Vapor propane
What is the refrigeration effect?
When the rate of vaporization can be exceeded. When the fuel has been refrigerated from vaporization to the point that there is little container pressure. ( more common in cold temperatures )
Multiply water capacity in liters by 0.42 to get propane capacity in_______.
Kilograms
1 liter = 1kg
What does air or moisture in a container do?
It absorbs the ethyl mercaptan, which makes propane leaks hard to detect.
• Moisture can lead to rusting
• Air can cause appliance problems.
What are the 3 elements required to start and sustain propane combustion?
Oxygen, fuel and heat.
What is the PSI for relief valves on TC cylinders and ASME tanks?
375 PSI TC Cylinders
312.5 PSI ASME Tanks
Cylinders must not be filled to more than what of their total capacity?
80%
What type of fire extinguisher is used for propane?
Class A
Liquid propane weight is?
0.5 of water
0.504 specific gravity
What is pascals law?
Pressure is equal and undiminished in all directions.
What causes pressure to increase and decrease?
Changing temperature
What is boyles law?
Pressure is related to temperature when the volume is constant
Why is the propane cylinder/tank filled to only 80% of its capacity?
To allow for 20% of vapor space for expansion.
Vapor pressure at 21°C ( 70°F ) is____PSI.
127 psi
Propane is ____ in pure state.
Odorless
The specific gravity of liquid propane is…
0.504
Propane gas specific gravity is…
1.50
What is the chemical makeup of propane?
What is the chemical makeup of butane?
C⁴H¹⁰
What is the boiling point of propane?
−42°C ( -44°F )
What is the boiling point of butane?
0°C (32°F)
What is the combustibility range of propane?
2.4 % to 9.5% propane.
97.6% to 90.5% air
Propane auto Ignition temperature.
540°C ( 1004°F )
Temperature at which it may spontaneously ignite without an Ignition source.
What is the propane flash point?
-104°C (-156°F)
Lowest temperature vapors will ignite with an ignition source.
Propane maximum flame temperature.
1979°C ( 3595°F )
What is added as an odorant to act as a warning agent?
Ethyl Mercaptan
Propane is detectable at?
1/5th of the lower flammability level.
( .48% )
How much does propane expand when changing to vapor state?
It expands 270 times in volume.
How much does propane expand for every 10°F it is warmed?
1.5% for every 10°F it is warmed
Propane is stored in…
A liquid state.
Propane is used in?
A vapor state
How many pounds is it per US gallon of propane?
4.2 pounds per US gallon of propane.
20 pounds of propane = 4.8 US gallons.
30 pounds of propane = 7.2 US gallons.
How many BTUs does one gallon of propane contain?
91,502 BTUs
Propane is a ____________ with the formula _____.
Hydro carbon
C³H⁸
Propane is a ____________.
Gas at a standard ambient temperature in pressure.
( 25°C at standard atmospheric pressure )
What must be upstream of a quick disconnect device?
Manual shut off valve
What is the flamability rate of propane?
2.4% - 9.5%.
The CSA Z240 code book requires that an excess flow valve not exceed what?
200 cfh at 100 psi
Backflow preventer at a remote fill is only required to be _______.
A single backflow check valve
A back flow preventor in the philva must have______.
A double backflow check valve.
B
L
E
V
E
Boiling
Liquid
Expanding
Vapor
Explosion
Are pressure relief valves adjustable?
No
What is a site gauge on an ASME tank?
It is only an approximate indicator of level.
What are 2 types of liquid level gauge?
1) Fixed maximum liquid level gauge
2) Sight gauge
Current valves use a ___________.
1-5/16” ACME Thread hand tightened connection.
Both liquid level valves have______.
54 Drilled orifice
Tc cylinder release valve pressure rating is.
3 70 5 PSI
