PROPANE TANK GAUGE ACCURACY - Page 2

unimogdave · 08-20-2011, 07:52 PM

Gavin
Thanks for the insight, I have learn more with this thread about propane than ever. One Question, what would make a gauge fail, I took the front off an realized it a sealed magnetic sensor. Some how the float is stuck on empty! but the tank is full!. Second you are very correct about the spitter valve can give you a very nasty burn,so muck for the wort on my finger. Lastly what is the life expectency of the pressure relieve valve? If its 18 years old can the spring in the valve get week?

Dave

Pntyrmvr · 08-21-2011, 06:53 AM

Dave;

The gauge is essentially the weak link in the tank. It has moving parts; the float and dial. These parts get jostled around leading to jamming and breakage. The pressure relief spring shouldn't ever fail, but the seal area at the tank can get corroded perhaps leading to a higher pressure requirement to blow it off.

These tanks need to be reinspected on a regular basis. 18 yrs without reinspection is false economy. Here that time frame is 10 yrs. Really old installations can even be required to upgrade the supply lines with more modern hoses. Contact your local major propane supplier for an inspection. The kid on the pump couldn't care less.

Lastly tanks are not supposed to be painted so that any corrosion from initial installation onwards is easily seen by the inspector.

I am always asked is propane safe? My answer is I would much prefer propane in a designed, welded, inspected and approved cylinder under me than a stamped sheet metal or plastic gas tank with no requirements to meet other than getting past the vehicle manufacturer's bean counters. (Google "Sherman Tommy cooker" to read an extreme example. Diesel is much safer than gasoline.)

Proof of this inherent safety happened recently when I cut into a disposable camping propane cylinder (painted green) hidden in a fence line I was clearing. The metal brush cutter blade put a 3/8" nick through it. The propane liquid/gas mix vented and all was well. A metal gas can would have been a lot less predictable as there would have been at least some oxygen in the can to support combustion.

Be safe. Get your cylinders inspected.

Regards,

Gavin

joey2cool · 08-22-2011, 02:05 PM

A few questions for clarification from all:

1. What is a "bleeder" valve? Same question, what's a "spitter" valve? The documentation lists the following valves on a 40# Manchester RV horizontal propane tank installed by SMB in 2010:
a) reflief
b) fill
c) vapor service
d) outage

2. What is meant by "tag-out" for riding on a ferry?

A couple notes on looking into the specs:

1. There is an auto-stop valve in the fill valve to prevent over-filling the tank. The label beneath this valve says to stop filling if liquid is seen on the outage valve (not mist) and have the auto-stop valve serviced. Sounds like something some of you don't have on your older models?

2. The sight glass is made by Rochester Gages, Inc. They make eltronic remote sensors too. I would expect it to be fairly accurate, and so I have elected to contact Manchester Tanks about the possible warranty issue (three years coverage on defective parts). Let's hope it's that and not a defective auto-stop valve that prevents the tank from being filled to capacity. I'll let you know what I find out.

Thanks for engaging your brains on this. It's a big help!

woodbee · 08-22-2011, 04:32 PM

"What is meant by "tag-out" for riding on a ferry?"

Last summer when we were going over to Vancouver Island B.C. The toll person asked if I had propane. I told her I did. She handed me a red tag and told me to make sure the propane was shut off and place the tag on the shut off valve. I believe it said not to open the valve while onboard the ferry.

Woody

Pntyrmvr · 08-22-2011, 06:23 PM

1. What is a "bleeder" valve? Same question, what's a "spitter" valve?

A couple notes on looking into the specs:

1. There is an auto-stop valve in the fill valve to prevent over-filling the tank. The label beneath this valve says to stop filling if liquid is seen on the outage valve (not mist) and have the auto-stop valve serviced. Sounds like something some of you don't have on your older models?

2. The sight glass is made by Rochester Gages, Inc. They make eltronic remote sensors too. I would expect it to be fairly accurate, and so I have elected to contact Manchester Tanks about the possible warranty issue (three years coverage on defective parts). Let's hope it's that and not a defective auto-stop valve that prevents the tank from being filled to capacity. I'll let you know what I find out.

Hi;

Bleeder valve and spitter are slang terms for the little screw valve that discharges liquid propane when the tank is 80% full.

The auto stop "outage" valve is doing the same thing to prevent an over fill condition. Auto stop has been around for years, but was not widely utilized in my time as a plant operator.

I would almost empty the tank and fill it using the auto fill. That volume should represent close to 80% of the water capacity of the tank. That water capacity should be stamped on the tank as WC and is in pounds. A gallon of propane weighs somewhere in the area of 6 lbs. (Verify on google!)

At 6lbs per gallon your 40lb tank at 80% should take 40*0.80/6 or just over 5 gallons to fill.

As noted in my earlier post those mechanical gauges are rarely accurate. Even the turbulence created during filling throws them off until the liquid settles to a smooth level. The tank must be perfectly level in both directions for the best reading.

Regards,

Gavin

Pntyrmvr · 08-23-2011, 11:03 AM

Hi;

An update here. This is for ASME style tanks only carrying automotive fuel- even though they don't fuel an RV or Sportsmobile that is what they are considered. Your normal BBQ style tank is a DOT style tank only because it can be moved by vehicle. Very confusing.

My latest research indicates that the ASME tanks (it should be stamped on the tank) in the USA do not need reinspection like the DOT tanks do. 12 years and then every 5 subsequent years for DOT tanks.

The ASME tanks are made with thicker steel so no need for reinspection.

That being said keep your eyes on the lines and connections given that a Sporty probably abuses these ASME tanks more than any other application.

Regards,

Gavin

joey2cool · 08-25-2011, 01:34 PM

Quote:

Originally Posted by Pntyrmvr

Dave;

Lastly tanks are not supposed to be painted so that any corrosion from initial installation onwards is easily seen by the inspector.

Gavin

SMB West's tank install looks to be powder coated. Manchester Tanks brags about this on their web page - says it provides better protection.

I've got a nick on one end and my propane system inspector said it's fine - no need to do anything about it. I still plan on doing an emery sanding and pen paint brush cover-up for it.

The note on these tanks being ASME may play into things - thicker steel being better for corrosion protection.