Propane Safety Scenarios
The Propane Safety Scenarios are intended to help you prepare for real-world scenarios, training class materials, or safety meeting topics.You can learn about these scenarios by visiting the PERC Learning Center. There you will find CETP modules to teach you more about each scenario.
Are your Employees Ready to Answer Customer Calls about Gas Leaks?
Your customer service representatives should take any customer complaints about gas odors seriously. The odors could indicate a propane leak. By applying company policies and procedures when those calls come in, your employees can help protect your customers, your employees, and the public from the hazards caused by escaping gas.
Click here to view PERC safety video with tips on what to do if you or a customer suspects a gas leak
Do Your Drivers Understand Gauges?
Can your bobtail drivers read the gauges that tell them the level of liquid in a container as they fill it? They can if they have the right training from CETP E-Learning.
Do Your Bobtails Have Meter Creep?
A meter creep test is designed to verify that a cargo tank’s internal valves will close when the emergency discharge control equipment is activated and that there is no detectable leakage through the valves in the closed position. A meter creep test should be part of your regular bobtail inspection.
Leak Checks: Using a High Pressure Gauge
NFPA code requires a leak check to be performed before any appliance or equipment is placed into operation or after an interruption of service. The leak check requirement applies to the entire vapor distribution system up to the outlets of the equipment shutoff valves. Many propane marketers, however, include the appliance connectors and the appliance gas controls as part of the leak check.
As opposed to a pressure test, a leak check includes the piping system connected to the appliance(s).
The type of testing instrument used in performing a leak check depends on the type of leak check being performed.
For a high pressure leak check, the testing instrument is placed after the first stage regulator and before the second stage regulator. This test usually uses a 30 psi gauge.
Leak Checks: Using a Magnehelic Gauge
NFPA code requires a leak check to be performed before any appliance or equipment is placed into operation or after an interruption of service. The leak check requirement applies to the entire vapor distribution system up to the outlets of the equipment shutoff valves. Many propane marketers, however, include the appliance connectors and the appliance gas controls as part of the leak check.
As opposed to a pressure test, a leak check includes the piping system connected to the appliance(s).
The type of testing instrument used in performing a leak check depends on the type of leak check being performed.
For a low pressure leak check, the testing instrument is placed into the low pressure system (1/2) lb pressure or less) at or after the integral 2 stage regulator or at or after the second stage regulator. The test instrument is subject to low pressure because the regulators have already dropped the pressure in the system.
Low pressure leak tests may be accomplished using a water manometer or magnehelic gauge.
Roadside Stop: Part 1: DOT Licensing and Driver Requirements
Drivers who operate commercial motor vehicles (CMV) to deliver propane must meet all of the U.S. Department of Transportation (DOT) Licensing and driving requirements. Before driving a CMV, employees must obtain there commercial driver’s license (CDL) and additional required endorsements from their state driving agency. Propane delivery vehicle drivers must also be aware of other driving requirements and restrictions, including rules prohibiting drug and alcohol use.
A road side stop performed by highway enforcement personnel is a bad time to test your knowledge of the rules.
Roadside Stop: Part 2 Vehicle Inspection, Identification, and Documentation
Regular vehicle inspections and proper maintenance are critical for operating propane vehicles safely and efficiently. U.S. Department of Transportation (DOT) requires propane delivery drivers to inspect their vehicles and document all maintenance before driving on public highways. Drivers must also be able to verify proper vehicle identification such as placards, shipping labels and data plates, and required vehicle documentation.
A road side stop performed by highway enforcement personnel is a bad time to test your knowledge of the rules.
Features of Vehicle Mounted ASME Tanks
Motor and mobile fuel tanks have a lot of features in common, and the increase in use of propane as a motor and engine fuel requires a good working knowledge of the many factors associated with this subject. Among those are the features of vehicle mounted ASME tanks that include:
- Data Plate and/or Cylinder Markings
- Fixed Maximum Liquid Level Gauge
- Float Gauge
- Liquid Service Valve
- Relief Valve
- Stop Fill/Auto Stop Valves
- Valve and fitting Enclosures
Click here to view the PERC "Features of Vehicle Mounted ASME Tanks."
Understanding Bulk Plant Tank Connections, Valves, and Gauges
The propane bulk plant is a specialized and complex facility where large quantities of propane are received, stored, and prepared for delivery.
Bulk plants tanks have several valves and gauges installed in either end, and in the top and bottom of the tank.
It is important that those responsible for operating and maintaining bulk tanks understand the location and of the valves and gauges, as well as their purposes.
With the proper education and training, new plant operators can effectively understand these critical functions and become valued employees.
Container Distance Requirements
The National Fire Protection Association 58 (NFPA 58) provides minimum distance requirements for setting various types of propane containers on a customer’s property.
These distance requirements pertain to ignition sources, vent/air intakes, building openings below level of (propane gas) discharge, and property lines/important buildings.
Many of the distance requirements vary with the type of container being set, such as an underground ASME tanks, DOT stationary cylinders, and above ground ASME tanks of varying capacities.
Products of Complete and Incomplete Combustion
Combustion is a chemical reaction that changes a fuel source, such as propane, into a useful form of energy, such as heat. Combustion requires all three ingredients: fuel, oxygen, and an ignition source. However, all three ingredients must be present in the proper proportions for combustion to occur. If a mixture of gas and air contains more gas than is needed for ideal combustion, then it is referred to as a rich burn. If a mixture of gas and air contains less gas than is needed for ideal combustion, then it is referred to as a lean burn.
The ideal combustion ration ("complete combustion") for propane is 1 part propane (4%) to 24 parts of air (96%). Even at this ideal ration, combustion products, known as flue gases, still occur. However, under this scenario, those products are harmless carbon dioxide and water.
Incomplete combustion (due to either rich or lean burns) may produce harmful combustion by-products such as carbon monoxide and aldehydes.
Most appliance burners are designed to burn a gas mixture that is as close to the ideal (4% propane) as possible, and may be regularly inspected by a qualified technician to ensure the maintenance of the ideal burn ratio.
Filling Customer Containers: Fixed Maximum Liquid Gauge vs. Float Gauge
Before filling the customers tank, this dedicated propane professional positions the bobtail, performs a site inspection, checks the liquid level in the container, sets the meter, opens the valves, and engages the PTO. He then prepares the hoses and filler valve, connects the hoses and checks for leaks and begins to fill the customer’s container.
As he monitors the filling process, he notices that the fixed maximum liquid level gauge is squirting propane liquid, but the float gauge only shows a reading of 70%.
Cylinder Filling Precautions
Understanding and following the steps and precautions to take when filling portable cylinders can avoid accidents.
Before filling any of the cylinders listed above, be sure to complete the following steps:
- Verify that the cylinder is designed to hold propane.
- Verify that the cylinder is free of any defects that require rejection or requalification.
- Check the latest test date to be sure that the cylinder is not due for requalification.
If the cylinder is 40 lb or smaller, used in vapor service (not a horizontal or motor fuel cylinder), and not equipped with an overfilling prevention device (OPD), it cannot be filled in most jurisdictions until an OPD is installed.
Personal Protective Equipment
The unsafe handling of propane can result in a serious or fatal injury to a worker, customer, or the public. Practicing safe work habits is a positive step to preventing accidents and injury. Safety is the responsibility of all employees.
When necessary, you must wear personal protective equipment (PPE), such as gloves, safety shoes, safety glasses, and hard hats to eliminate on-the-job accidents. Using personal protective equipment requires hazard awareness and knowledge of the equipment’s purpose, limitations, proper fit, and maintenance.
OSHA regulations require the use of PPE during operations that present the risk of injuries to employees that cannot be controlled by engineering or process procedures. OSHA requires the employer to:
- Determine the use and selection of PPE
- Train employees on the proper use and care of PPE
- Document employee use and care of PPE
In return, employees are required to properly utilize and care for the PPE that has been assigned.
Click here to view the PERC Personal Protective Equipment site.
Effects of Temperature and Pressure: Part 1: Propane Vapor Demand
Understanding the effects that heat and pressure have on liquid propane is critical to understanding how propane behaves. Propane is affected by heat and pressure in much the same way as water. At atmospheric pressure the boiling point of propane is -44Fo. At any temperature below that a pool of propane will remain in liquid form, because its vapor pressure is less than atmospheric. At temperatures above -44Fo, the vapor pressure of propane is greater than atmospheric pressure, therefore the liquid will vaporize.
Keeping this in mind, when the valve of a propane appliance is open, propane will flow to the burner, and the demand for gas vapor will immediately cause a slight drop in pressure inside the container. This upsets the heat/pressure balance and causes the propane to begin boiling off vapor to replace the vapor going into the burner.
As long as the demand for propane remains, the propane will continue to boil, supplying fuel to the burner.
When the valve on the appliance is closed, the propane will stop flowing and return to its balance point. The boiling will eventually stop as the balance is reached.