Liquefied Propane Gas (LPG) has powered our forklifts for decades. It's easy to forget that it's also a highly flammable gas, capable of causing terrible damage!
With all the workplace and safety changes over the past year, it's good to refresh our memories on safe LPG use. That’s what this month's newsletter is about.
The Dangers of LP Gas
Let's start with the dangers to workers. They rarely happen, but they're always a risk. LP gas presents 4 distinct dangers:
- Fire hazard - LPG catches fire very easily!
- Suffocation hazard - If LPG leaks, it will evaporate and form a large cloud of gas, which will settle in low spots such as drains or basements. This can asphyxiate workers.
- Cold Burns - LPG can cause burns if it makes contact with the skin.
- Illness - Breathing in LPG fumes can make you sick.
LPG Tank Valves
Here's a photo of a bulk LPG tank, normally used for refilling cylinders. It has four valves on its top.
Red Circle – the 10% valve. Opened during filling procedures. This is your gauge to a fully-fueled tank allowing 10% for expansion from heat or weather conditions. You'll open the 10% valve while fueling. Watch for white fuel to escape this valve, signaling it's time to shut off the flow.
Blue Circle – the relief valve. This valve will blow out the fuel in case of emergency (overfilling, pressure exceeds the tank maximum).
Yellow Circle – the valve assembly, with shutdown valve. This valve connects to the forklift and provides fuel. This is also the point at which most leaks occur, due to the coupling's two O-rings. If disturbed while filling, the O-rings lose seal, causing a leak.
Green Circle – the fill valve. Used to fill the tank by operators using bulk filling, or by your propane supplier. The yellow cap must stay on at all times, to keep any objects from hitting the valve and releasing LP gas.
Propane containers come in two types: the DOT cylinder and the ASME tank. The NFPA's Pamphlet 58 states that all DOT cylinders must be "recertified" after 12 years from the manufacturing date.
What does "recertified" mean? A proof of regular inspection for safety. Recertification involves a documented inspection and testing of the cylinder, in order to confirm that it's still safe to use.
ASME tanks do not need recertification. However, they should have their relief valves replaced every 10 years to maintain the same safety standards.
LPG Handling & Safety
3 tips for safe handling of LPG tanks:
- Don't strain yourself! A full steel tank of propane can weigh as much as 70 pounds. Save your back – use a pallet jack (and tie the tank down).
- Before moving a tank, always verify its valves are closed.
- Always, always wear gloves and protective equipment when connecting/disconnecting hoses from propane cylinders.
Filling Procedure for LPG Tanks
This is a standard filling procedure for an LPG cylinder on a forklift.
- Lower any load the forklift carries. Shut off the forklift completely.
- Put on LP gloves, safety glasses, and a face shield.
- Insert a ground strap into the LP tank.
- Remove the fill valve's yellow cap.
- Verify that the valve on the main hose, for venting excess gas when finished, is closed.
- Connect the main hose from the bulk tank to the LPG tank's valve assembly.
- Open the main hose's valve.
- Open the 10% valve slightly.
- Turn on the electric pump at the bulk tank. Fueling begins. Listen for any hissing noise.
- Wait for the LP gas to escape the 10% valve.
- Turn off the electric pump after you hear the 10% valve.
- Close the 10% valve.
- Shut off the main fuel line valve.
- Release the excessive fuel in the main hose.
- Disconnect the main hose from the LPG tank.
- Reinstall the fill valve's yellow cap.
- Remove the ground strap.
- Return the safety gear to storage. Forklift is refueled and ready to resume work.
Safe Storage for LPG Tanks & Cylinders
Generally speaking, you should store small cylinders up to 420 lbs. (100 gallons) outside. They should remain at least 15 feet from a building opening (window, door, vent). Keep small cylinders/tanks in a rack to avoid any water pooling.
Store larger tanks (100 – 499 gallons) 10 feet away from the building or property line. Tanks from 500 – 2000 gallons must stay 25 feet away. 2000+ gallon tanks, 50 feet away.
You may need to place protective barriers around, or concrete foundations underneath, larger tanks. Check with your city planning department or fire department for the current regulations.
Finally, NEVER store any size propane tank in a high-traffic area – near a stairwell, doorways, or inside an office.
Propane gas has no odor. An odorant, ethyl mercaptan, is added in order to detect leaking. If you smell an unpleasant scent like bad garlic or a skunk, you've found a propane gas leak.
Smell isn't the only way to detect leaks, however. Keep an eye out for:
- Oily film around the valve or fittings.
- Sound - a hiss or high-pitched squeal indicates a severe leak.
- Quick loss of fuel. If your fuel level drops faster than normal, you may have a leak in the line.
- Frosting/freezing around a valve or tube.
To check for leaks, whether you suspect one or just want to make sure, use a liquid leak detector or gas sniffing device.
Safety Procedure if Someone Smells Gas
Chances are you already have an emergency procedure in place if someone smells gas. I'm including one for completeness' sake.
- If you smell gas, report it to your supervisor immediately.
- Move everyone away from the area.
- If the leak is on a propane container, move it outside and place away from any ignition source. If the leak is on a fuel line (vapor or liquid), shut off the fuel flow by closing the service valve.
- If it's not possible to move the leak source outside, call your propane supplier. Not available? Call 911.
- After resolving the leak, check the forklift over thoroughly. It may have triggered the leak due to some fault in its system.
Refresh Now, Avoid Accidents Later
If this refresher has reminded you of something related to LPG safety, no matter how small, then it's done its job.
Everyone in our industry works around propane all the time. The fact that we have so few accidents with it shows how serious we take its safety. Even so, a little reminder now and then can help us all keep that safety level up.
Until next month!
Marshall Cromer, The Forklift Boss
Cromer Material Handling