The following information is provided free from the Canadian Centre for Occupational Health and Safety. It is one of several very good short forklift informational publications that can be downloaded.

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OSH Answers

Safe Handling of Propane (LPG) Fuel

What should an operator do when handling propane fuel?

* Position the tank so the liquid propane does not come in contact with the relief valve.
* Make sure the locking pin engages into the cylinder.
* Make sure the valve is closed tightly.
* Store the cylinder outside, in an upright position, in an area where it can be secured and is protected from being struck.

* Put the cylinder down gently. Do not drop, dent or damage.
* Always protect the valve from any damage.
* Avoid contact with liquid propane, as it can cause frostbite.
* Wear protective gloves while making or breaking connections
* Ensure that only qualified persons repair carburetors and fuel supply systems.
* For repairs, use only components that agencies such as the Canadian Standards Association (CSA) have approved.
* Exchange removable cylinders outdoors or in well-ventilated areas, away from sources of ignition.
* Close the valve before breaking connections.

What steps should operators follow when changing fuel tanks?

Procedure for changing propane (LPG) cylinders:

1. Wear eye protection and insulated, loose fitting gloves such as leather (dry) or insulated neoprene.
2. Close the valve on the cylinder.
3. Run the engine until it stops. This ensures that the connection hose is empty.
4. Shut off the engine.
5. Open the connecting nut and inspect valves for leaking. Do NOT use metal tools.
6. Disconnect the hose.
7. Disconnect the holding straps.
8. Remove the empty cylinder.
9. Replace with a full cylinder in the proper position.
10. Connect the holding straps.
11. Tighten the connecting nut (wiggle hose).
12. Open the valve on the cylinder slowly and check for leaks. Use solution of soap and water. Smell--listen--look.
13. If the valve leaks:
1st time - Tighten the nut and continue.
2nd time - Change the cylinder.
3rd time - Change the hose.
14. Open the valve fully (slowly).
15. Check that the hose is turned inward.
16. Secure the hose downward.
17. Secure the cylinder.
18. Start the engine and resume operation.

What should an operator not do when changing a propane tank (cylinder)?

* Do not use metal tools when changing a cylinder.
* Do not let the cylinder get too hot.
* Do not use matches or a flame to check for leaks. Use soap or a leak detector.
* Do not mount more than two LPG cylinders on any forklift truck."

Document last updated on March 21, 2002

Copyright ©1997-2005 Canadian Centre for Occupational Health & Safety

Vic
An earlier reply gave a pretty complete procedure for changing tanks and although your question related to changing a tank; may I add a similiar procedure for the end of the day - if the truck is not going to be used overnight or for the weekend.
Pretty much the same:
With the engine at idle, turn the tank off, rev the engine til it stalls, try to restart the truck 2 or 3 times then shut the key off.
In the morning, give the tank 1/4 to 1/2 turn, start your truck and with the truck idling, slowly turn the valve on all the way.
The key words here are slowly and all the way.
PS: If anyone stores their propane lift truck in an unheated warehouse and have a problem with starting - especially on a Monday morning.....try this shutdown procedure and you should be pleasantly surprised.
Regards
Garry

The operators handbook should contain instructions which would in th emain be very similar to dan_m's input. The only additional comments I would make is that a visual check should be made of the gas bottle, hoses and connections to ensure these are in good condition. The larger bottles are quite heavy also and attention should be paid to manual handling limits.

#1 no smoking
#2 do circle check and determine whether the tank must be changed
#3 If so, drive the truck to a well ventialted area
#4 Neutralize the truck, neutral, parking brake and forktips flush
#5 Put on safety gear and shut off on/off valve
#6 rev the engine til it dies
#7 restart engine to ensure fuel line is purged
#8 Shut off engine
#9 remove the cylinder
#10 Store cylinder according to local fire codes
#11 Check new cylinder for date/damage
#12 Install cylinder with safety relief valve at 12 o'clock
#13 reconnect couplings
#14 Open on/off valve 1/4 turn, then all the way, check for leaks
#15 If all fine, lock her down

Hope this answers your question.