PLEASE TELL ME EVERYTHING YOU KNOW ABOUT PROPANE

[Rebel]

Stockman,
Using your method I've calculated that when its the middle of January the morning low temp is -6F, I'll have -12 psi in my tank, that a pretty good vacume! All kidding aside , it gets that cold and colder in this corner of the Rockies. Typical lows during the winter months run in the teens. The all time record low is -28F.

What I'd like to know is at what temp. do these types of systems not function as intended? I'll contact the manufactures and post any results that are obtained.

HVAC, if you have a pressure/temperature saturation chart for propane could you please email it to me? Thanks in advance.

[This message has been edited by Rebel (edited 08-13-2000). ]

 

[willyslover]

Just a THANKS to all who got involved in this thread... I have learned more on this thread than I can say. .
thanks to all
Gary

 

[AFarnham]

Checked Marks' Handbook for ME's, fig 19. 1. 5. Propane is ASHRAE refrigerant #R290. Graph shows:
Psi F
0 at -44
15 at -40
23 at -20
35 at 0
50 at 20
70 at 40
100 at 60
150 at 80
200 at 100

Low temp problems will relate to the friction loss over a section of piping from required flow rate vs vapor pressure available to "drive" fluid in the line. You could ultimately use a small transfer pump to supply liquid propane to a vaporizer, which would need heat. The pump, electrical system and any enclosures would need to be designed for safe transfer of a combustible fluid. Could be done, might be expensive. Might also not be a problem, depending on what the mfg's using.

 

[Rebel]

Stockman, THANKS-for the info! #ad

 

[HEMI®Dart]

I have a simple question for you guys.

I am thinking about mounting a BBQ (D. O T. ) approved in the bed of my truck. It has a (black) tonneau cover. It can get hot in there during the summer, parked all day at work in the sun.

Do you think this is OK or dangerous?

Should I roll back the cover on hot days? Or open the tail gate?

 

[Bart Timothy]

I've run 2 BBQ tanks with a change over valve in my bed toolbox this whole summer (many days over 100 deg) with no problems. I believe the new style BBQ tanks are safe in this enviroment and satisfy DOT - at least that's what Wasatch Propane here in SLC says. What you need to look out with this style of tank is the use of restricted fittings. The tanks themselves are restricted but provide enough flow for our use. Try to find fittings which have the check valve but aren't restricted in the feed and the whole thing will work good.

Here are some more interesting facts.

If you compress propane it turns into a liquid; it needs something external for ignition. If you compress diesel it explodes. These engines need some diesel to ignite the propane. They can't soley run on propane only.

 

[AFarnham]

Propane cylinders are designed, per federal regs or American Society of Mechanical Engineers standards, to withstand 250 psi in normal service. The cylinders are provided with pressure relief valves designed to vent a portion of the cylinder's contents when this pressure is exceeded by 20% or so.

The goal is to keep the cylinder wall from failing. I've seen the results of this, and when followed by ignition of the escaping fuel, is quite spectacular - remodels buildings quickly.

The pressure can be exceeded in two ways - either by overfilling followed by heating the cylinder, or from excessive gas pressure from too high of a temperature.

If the cylinder is properly filled, it should be OK up to about 125 F. The new style cylinders have provisions to prevent overfilling IF they are filled in the upright position. The best way to fill a cyilnder is to weigh it to be sure it doesn't contain too much fuel.

National Fire Protection Association (NFPA) LP Gas Code addresses vehicle fuel systems in Chapter 8. This code has been adopted by many jurisdictions as an installation standard. While it is boring reading, it has a lot of good stuff to help make your installation safe. It's available from NFPA at 800-344-3555 or www.nfpa.org for a little over $30. The LP Gas Code Handbook has more information, but is more than twice the price.

Just thought you'd want to know.

 

[Mopar-muscle]

heres a question , not sure if it was asked , i'll need to reread , what about going thru tunnels that have signs posted , NO PROPANE , will we have to drive around them ??? arcticat , email me , we need to finalize the swap ...

 

[HEMI®Dart]

Thanks for the info Stockman. #ad


Stockman, Will propane vapor ignite if it reaches the intake grid heater on our trucks when the heater is energized?

[This message has been edited by HEMI®Dart (edited 08-24-2000). ]

 

[HVAC]

Mopar Muscle, I don't think they will let you through the tunnels with say an RV due to the presence of propane. If it's under the bed likely nobody will know #ad


Hemi-Dart, you should not have any propane in the intake system while the grid heaters are on since the regulator will not respond without a significant vacume. The way I have my truck setup I need 6 psi of boost before I get any propane into the engine. Also, I would recommend a toggle switch be installed in the dash to master arm the propane system with whichever system you install. This will allow you to leave the system off till your truck is warmed up if you feel the need for further measures.

A clarification, DOT standards are what govern OTR tanks(for RV's, BBQ's and motor fuel), not ASME. ASME standards are applied to the tank you may have in your yard to serve your home. The relief valve pressures are set for 350 on DOT tanks where ASME tanks are set at 250, just an example of the differences.

Also, a properly filled cylinder will withstand much more then 125 degrees. Manchester randomly tests their product to ensure the tank will not rupture at less then 1000 psi. In my personal fire training experience we had to use large burners focused on a vessel to create enough pressure for the relief valve to open. This is a controlled situation for demonstration purposes. A tank typically would have to be involved in a fire before the tanks integraty is in jeopardy or the relief valve would open. The only relief valves I have seen open were a result of tanks involved in fires or improperly filled.

 

[HEMI®Dart]

Thanks HVAC,

I was just asking incase of a major malfunction.

The kit has a Hobbs Pressure switch that won`t will flow propane below 7 lbs boost. I may adjust it a little lower. System on/off Toggle switch included too.


I emailed the manufacture of the system about potential hazards. He said the system is safe. Guys start having problems when they try to modify the system for higher horsepower.

[This message has been edited by HEMI®Dart (edited 08-24-2000). ]

 

[HEMI®Dart]

HVAC,

Do you shut off the valve at the tank at night?

Do you park your truck in the garage?

( The directions for the kit don`t answer very many questions #ad
)

[This message has been edited by HEMI®Dart (edited 08-24-2000). ]

 

[HVAC]

I am not aware of a reason to shut the tank off. You never know when a PSD will sneak up on you and evasive manuevers will be necessary #ad
If you park in a garage maybe it is a good idea. If you install the proper components in the correct fashion you should not have any problem short of a meteorite shower #ad


Damage to the engine can occur if you modify the system. I just got off the phone with "DieselWizard" who just installed an ATS system(on a PSD) and he was not impressed. He drilled the orifice and now he is getting wood #ad
I would mention that I have heard(second hand) that a couple Cummins engines met there demise via the modified propane system route. I had detonation at a point but backed out. Then I reversed the modifications to make sure the system was not going to hole a piston. BOMB wisely #ad

 

[HEMI®Dart]

I have a Hobbs pressure switch like this one:
TOP ONE
#ad


It is pre-set at the factory to activate propane flow @ 7lbs. boost. It is adjustable.

There is a 7/32" allen screw under the rubber cover.

My question, To make the switch activate at say 4lbs boost, do it turn the screw OUT or counter clockwise?

Or do I turn it IN or Clockwise? I think the former.

Also any ideas how many turns or 1/2 turns to increase & decrease activation per lb. boost?



[This message has been edited by HEMI®Dart (edited 08-27-2000). ]

 

[ynot]

Under normal circumstances, turning in puts more pressure on spring, thus increasing opening pressure. Out, likewise, will decrease opening pressure. An air regulator and a continuity meter would read the set pressure. If none are available, screw it out, COUNTING THE TURNS, until you lose contact with the spring. This is "0". Take opening pressure into screw revolutions. Subtract the desired turns to achieve desired psi. This will get you close, tho the actual opening pressure increases faster the more the spring "loads up"... T

 

[HVAC]

Yup, I concur. Turning the adjustment in will increase the pressure at which the switch will close or "make". I have the switch illustrated in the upper pic.



[This message has been edited by HVAC (edited 08-29-2000). ]

 

[HEMI®Dart]

Thanks ynott & HVAC

I found this graph. I was worried the relief valve would open on the tank under my tonneau cover in hot weather. Not really worried now.

#ad
This graph shows that as the temperature increases, so does the pressure-regardless of how full the tank is. At 312. 5 PSI (2. 15 MPa) the pressure relief valve on an LPEFI propane tank will vent propane, to prevent excess tank pressure. Note that at -44 °F (-42 °C), the pressure in the tank is essentially zero.


Now I see why the directions say " outside air tempature variations may require different regulator adjustment screw settings" #ad


[This message has been edited by HEMI®Dart (edited 08-29-2000). ]

 

[Bart Timothy]

Propane has close to the same gas/liquid/pressure/viscosity properties as Freon 22. Any items which control F22 could probably be used with propane as long as flameability is kept in mind.

 

[Joseph Donnelly]

I don't know, but think the grid heater gets pretty hot since it has to raise the air temp appreciably. It is not on for long, however, at one time.

I have an air intake from a 24 valve that has the clear coat burned dark brown from the grid heater-the solenoid stuck open. That's the kind of failure that could ruin your day if you run propane. I think it might be prudent to deactivate the grid heater when running propane enhancement.

 

[BRoth]

Very good banter fella's, lots of good information.

One concern though. Ynott you mentioned that Propane is not government regulated? Maybe there are some States that do not but I would think not many.

A vehicle that has not been certified by a licensed propane tech is not allowed on any ferry. If you do get in a accident and propane is present you better have the right fittings, hoses, tank that is certified or you are in for some serious problems other than just the accident.

All RV's must have a certified sticker and propane tanks must be recertified every so often.