Hello
There is Propane additive that helps with these type of problems. it is made by Valtect Petroleum Corp. and it has a very long history of successful use precisely in forklifts. Its name is CGX-4. Please let me know if you need a contact in the US

I'm located northwest of Phila Pa and can tell you that around here there's only 1 LP vendor which will give out a certificate that their fuel is HD-5. I've had all kinds of fuel related issues. The in-line thermostat from the regulator helps but doesn't solve the problem. The LP fuel injected lifts I work on have a constant problem with the injectors clogging with tar. I've gotten a couple of my customers to switch to the known HD-5 & the injector clogging went away. My other customers won't change LP vendors & the problems persist for them.

When talking with LP vendors around here, they all say they sell HD-5 until you ask for certification, 'they say they'll get back to me & I never hear from them again. I can tell you that anything but HD-5 will stink when the forklift is running (smells like burnt LP). That's how I tell which LP is running thru the system.

So many problems with this grill, so only the husband is engaged in this grill. husband, by the way, recently bought a great grill https://bestgrill.reviews/best-smoker-grill-combo/ with which I manage to cope. It is very easy to use.

Proshadetree, an elbow,a length of pipe, and a cap, and draining those converters will no longer be a problem.

E,
I get it! I have removed numerous of these during a reg swap, assumed it was a one way check valve! So by keeping the temp at my model J lower I can minimize the build up of oil? I guess it could be installed on either side of the regulator? I am already thinking of a few customers with excessive oil build up that would benefit from this fix. Can this thermostat be sourced from SMH?
Steve

I am soooo tempted to just to answer with just; "2nd law of thermodynamics".,

but I won't, but it will give you something to think/google about.

If you stop the flow of coolant through the regulator, the physics of expanding molecules absorbing the heat from the surrounding area will cool the regulator,
That is the reason behind the cigar shaped thermostat* in the coolant line after the regulator. when you stop the flow completely, the regulator could freeze up.
*= this thermostat woks a little different than the engine block thermostat, in that it closes at the rated temp, stopping the flow, allowing the water in the regulator to be cooled by the expanding gas.

Great topic.
Doc,
How could you regulate the coolant temperature going to the regulator? Cooling system temp should be around 185*F so to achieve lower would reqire another source of coolant possibly?
Steve

I try to drain mine when serviced so when you make the preheated filter could you make a drain plug I can get to without doing yoga to get at

reponse to SAWB : I would imagine if it "was JUST that simple " the refiners would be doing it. Propylene is a valuable commodity to the Petro-Chemical Industry and is bought and sold in the chemical market place.

Propane and propylene seperate at approx 100 degrees. I have had customers in the past that had regulators last days before being filled with propylene. I have noticed that the problem is at its worst during the summer and the customer was at the end of the propane delivery route. High ambeint temperature causing the mixture to begin to seperate? Customer requested different position on delivery route and the problem went away.

If we know that the propylene separates at a given temperature wouldn't it be the cheap easy fix to the clean propane problem. Fuel could be heated during the refining process to seperate the impurities. Should the prefilter be heated to seperate the propylene? This would be cheaper to replace or clean than a new fuel injection regulator at $800.00 + per unit. Maybe I should go in to business.

Cure is to regulate the Vaporizer temprature to below 140 degrees Farenheit.

I think that is correct.

Did a little "GOOGLING" on "PROPANE" and after reading several sites found out that "PROPYLENE" is a BI-Product of the "cracking" process and that it is extracted from the propane to be sold for making other products IE: plastics.
The problem is they cannot extract all of it with the traditional methods so there is a percentage of it left in the propane.
They say it takes an additional process to completley "DRY" the propane and they are working on a cost efective to extract all the propylene.
The Refiners who make the propane, some are able to get more out than others, maybe why some places have more problems than others because of the amount of propylene in there propane----

Drlifttruck now thats doing your homework.Still dont explain the sludge buildup in one area and clean as a pin in others.Maybe dirty tanks?

This is not my copyright, but what I already knew.

Hope you find it useful.
Grades of Propane - Gas Purity and Quality

Propane is considered propane regardless of the grade but the reality is that three grades of propane are processed or refined in the United States. Each of the three grades, HD5, HD10 and commercial propane differ in propane consistency and are used for different purposes. All grades of propane come from the same raw materials (crude oil or natural gas). The differing grades are created during the refining or processing of the gas at the refinery. In other words, the refinery specifies which grade is to be processed. Each grade of propane is stored separately following processing to ensure that the propane grade loaded at the refinery is what was specified by the buyer.

HD-5 Propane
HD5 grade propane is "consumer grade" propane and is the most widely sold and distributed grade of propane in the U.S. market. HD5 is the highest grade propane available to consumers in the United States and is what propane companies ordinarily sell to their customers. What does HD5 propane mean in terms of specification to an ordinary consumer? It means that the propane is suitable and recommended for engine fuel use, which was the original purpose of the HD5 grade propane specification. HD5 spec propane consists of:

Minimum of 90% propane
Maximum of 5% propylene - propylene is used in the manufacture of plastics
Other gases constitute the remainder (iso-butane, butane, methane, etc.)
The HD5 specification is based on "allowable" contents. For instance, 99% propane and 1% propylene is HD5 grade propane the same as 95% propane and 5% propylene is HD5 propane. Although the product consistency and purity is different, both mixtures are considered HD5 propane because they fall within the allowable limits for the product to be named and labeled as such. Consider this: 10,000 gallons of pure propane (100% propane) is classified as HD-5 grade propane.

HD5 Propane Quality - Fact vs. Fiction
Retail propane companies that advertise "highest quality propane" are actually selling propane that conform to the specifications as required to be labeled and sold as HD5 propane. An important fact to note is that there is no higher grade than HD5 propane available for resale through retail propane companies in the United States...HD5 is the highest grade propane available to U.S. consumers. A company stating that their propane is of a higher grade than HD5 is inaccurate in their claim. As presented above, a tank holding pure propane contains what is classified as HD5 propane.

HD-10 Propane and Commercial Propane
HD10 propane is a grade below HD5 and is commonly found in California. HD10 grade propane allows up to 10% propylene in the propane/propylene mixture and is still labeled as "propane". Because propylene is used in creating plastics, HD10 can possibly create problems in some engines and vehicle applications. Propylene can cause engine components to "gum" or stick during operation. However, HD 10 spec propane works just fine in domestic and commercial propane powered appliances. The only problem that may be encountered in using HD-10 propane involves its use as an engine fuel (vehicles, forklifts, etc.).

Commercial grade propane and HD10 grade propane are sometimes used interchangeably due to the fact that both grades are sub-HD5 spec product and do not meet the standards of engine grade propane. Refineries use commercial propane in their processes and fractionation of chemicals for end use in numerous industries. Although commercial grade propane can be used in a manner similar to that of HD10 propane, it is not used in vehicle applications.

Tucks have had them from factory.HD5 is also cleaner than regular propane.After this thread posted Ive asked sevral of my customers what they run most dont even know there is a diffrence.Check with supplier HD5 is in all of my customers that have clean vaporizers,Which is less than 1/4.The rest is unresolved or havent found out yet.Some of these trucks run 210 and up due to dirty workplace.Can we say code E32.I hate clearing that code on older trucks newer not as bad.Thank goodness they are on a 3 year lease and new will arive soon