Propane Question - Should I be Worried?

[deblen]

Originally Posted by john61ct

Well the gauges are available for all types, kits are available that can easily be customized by a qualified tech.

But I certainly wouldn't bother fitting one to anything under a 20#

https://www.amazon.com/gp/aw/d/B00JABY5EC

Not to my 1# and 6# bottles, would be easier to just weigh them.

But with a large installed tank like on an expedition truck, that should be a standard part of any install, usually with a display combined with bank SoC monitors and level indicators for grey/black/fresh water tanks.

I believe Votronic makes a nice central panel like that.

These are true float level gauges & would be a nice feature.
They tell you how much propane is left in the tank.
However,they will not replace the pressure gauge required for leak test by ABYC.

[john61ct]

Yes, nothing to do with each other.

A level gauge is for convenience, not safety.

Note a low tech solution to running out unexpectedly is dual tanks with an auto-switching regulator. But you need to open the locker to check, I don't know of any that remotely notify.

A pressure gauge does not tell you how much lpg a tank holds, just that it's run out, right when it needs swapping.

[Jim Cate]

n addition,a propane alarm is required,with the sensor mounted right below the joint/connection to the appliance (near the floor). As stated in the article,if the propane sensor is mounted under the floor(in the bilge area), it will be too late-you now have propane in your bilge!

True, but the detection level of the alarm is far below the minimum explosive limit for propane, so all is not lost and it is not too late!

I'd say that there is at least some probability that a slow leak at the joint could be missed by a sensor mounted directly below it if there was any air flow in the area, diluting or diverting the gas. A bilge mounted sensor would detect the slow accumulation from a tiny leak long before the explosive limit was reached, and thus seems a better choice.

The explosive limits for LPG are roughly 2% to 10% by volume. One's nose will detect the oderant in LPG long before that 2 % value is reached... that's why it is there!

I appreciate that the destructive power of a fuel/air explosion is huge, and that some such explosions happen each year worldwide. My expectation is that most of them are from the sort of mickey mouse installations BoatPoker illustrates, not from the occasional minor infraction of ABYC standards.

And BTW, those standards are not universal. Here in Oz, for instance, they vary from state to state, but in general the long run of uninterrupted hose touted upthread would be illegal.

Jim

[Dockhead]

Originally Posted by Jim Cate

. . . My expectation is that most of them are from the sort of mickey mouse installations BoatPoker illustrates, not from the occasional minor infraction of ABYC standards.. . .

I suspect you're right. Most of the several per year explosions we have in the UK are canal boats and motor boats or the occasional small, old, neglected yacht.

HOWEVER, note well the story of the Lord Trenchard explosion. That's the case which really shocked me, and shook me out of complaisance. That was no mickey mouse installation, and no slack, ignorant crew. That's the one case which really proves that any one of us, could blow ourselves up.

There's a certain risk that all of the "best practice", as we know it, as set forth in ABYC or BSS, cannot mitigate. It does really only take one slip-up. You really cannot be too careful with this stuff. And that's a good argument for not having it on board -- I don't want to have anything on board you "can't be too careful" with.

[Jim Cate]

I don't want to have anything on board you "can't be too careful" with.

I guess one could make the same statement about the large amounts of electrical energy you propose for your next boat! It would be interesting to compare the annual losses of property and life due to electrical and propane hazards on boats.

Jim

[boatpoker]

Originally Posted by Jim Cate

I guess one could make the same statement about the large amounts of electrical energy you propose for your next boat! It would be interesting to compare the annual losses of property and life due to electrical and propane hazards on boats.

Jim

BoatUS says ..... "Faulty wiring causes most fires"

[boatpoker]

More from BoatUS ....

[boatpoker]

More from BoatUS.....

"Stoves. The incidence of fires due to stoves has decreased with the gradual replacement of alcohol stoves with propane stoves and electric ranges. Two percent of fires were caused by stoves, more than half resulting from problems with lighting alcohol stoves. Given how few alcohol stoves there are on boats these days, they are significantly more dangerous than those that use other fuel sources. If you still have an alcohol stove on board, you may want to consider upgrading. Most people agree that they don't heat very well, anyway."

[wsmurdoch]

My local U-Haul dealer has 20lb US propane tanks with level gauges for sale for $38 inc tax. I gave them a pass and will continue to weigh my tanks with my 0 to 50lb fish (spring) scale. I think it is cheaper and more accurate.



Worthington makes it.

[Dockhead]

Originally Posted by Jim Cate

I guess one could make the same statement about the large amounts of electrical energy you propose for your next boat! It would be interesting to compare the annual losses of property and life due to electrical and propane hazards on boats.

Jim

Yes, it's an absolutely fair question.

I think electrical power is less uncontrollable, but that may be merely emotional prejudice on my part. Worth studying.

[Suijin]

Originally Posted by Jim Cate

I appreciate that the destructive power of a fuel/air explosion is huge, and that some such explosions happen each year worldwide. My expectation is that most of them are from the sort of mickey mouse installations BoatPoker illustrates, not from the occasional minor infraction of ABYC standards.

I think it's one of those things where while the chances of an "incident" in the case of a properly constructed locker and system are exceedingly low, the consequences of a failure can be exceedingly dire.

All it takes is a leak in the hose to the stove in any installation and a shorting bilge pump switch and you have a bad situation. Ergo the advice to change the hose every few years.

As with many safety issues on a boat, attentive maintenance and following best practices reduce the risk to near zero.

[skipgundlach]

Originally Posted by Jim Cate

The explosive limits for LPG are roughly 2% to 10% by volume. One's nose will detect the oderant in LPG long before that 2 % value is reached... that's why it is there!


Jim

Thanks to Jim Cate for answering the question I posed the alarmist jmschmidt earlier:

I would appreciate being schooled: What concentration (use PPM or whatever the industry standard is) of propane will ignite, let alone explode, in the presence of a lit cigarette (not open flame or spark)? And what rate of flow is needed to support that level of concentration in an open (presume windless, to help the assertion) environment such as (no wind, so) flat water or ground? And, now that you have that information, how long would a full 20# tank of propane take to empty at that flow rate?

Well, the first part, anyway. Thanks!

Now to the question of how much propane you'd have to have stored, and leaked out, at what rate, to cause that innocent cigarette-waving SUP'er (or the more likely scenario posed of a same-styled yard worker) to blow himself and the boat to smithereens

[Pete7]

Originally Posted by wsmurdoch

My local U-Haul dealer has 20lb US propane tanks with level gauges for sale for $38 inc tax. I gave them a pass and will continue to weigh my tanks with my 0 to 50lb fish (spring) scale. I think it is cheaper and more accurate.

Good idea, but in a large number of countries around the world gas tanks are rented from the supplier were you exchange your empty one for a full one. You don't own the tank. There are some advantages to this, old rusty or dented tanks are dealt with by the supplier for free so effectively removed from circulation. Individuals are not responsible for arranging for tanks to be tested, again a suppliers responsibility.

Pete

[Pete7]

Len, I assume that this refers to systems were the regulator is mounted on the wall of the gas locker and a medium pressure hose runs from the cylinder to the regulator.

The UK still has this system, but increasingly we are using regulators directly attached to the gas cylinder and then low pressure flexible orange hoses to join the copper line. I have a jubilee clip holding the flexible hose onto the copper pipe.

Pete

Originally Posted by deblen

You are correct. The only joint allowed by ABYC in a propane line after it leaves the regulator in the propane locker is the connection at the ONE appliance. However,you are allowed & encouraged to use a short length of propane rated flex hose with factory crimped fittings between the appliance & copper supply line(If copper was used).These hoses are available all made up for < $10 at any RV supply.

Euro boats often have some type of rubber hose slid over 3/8" copper tubing & hose clamped. This is a no-no!

Safe Boat Propane System Installation

Please note the comment in the above article about Englishmen playing with electricity & French playing with propane.

/ Len

[skipgundlach]

Originally Posted by Pete7

Len, I assume that this refers to systems were the regulator is mounted on the wall of the gas locker and a medium pressure hose runs from the cylinder to the regulator.

The UK still has this system, but increasingly we are using regulators directly attached to the gas cylinder and then low pressure flexible orange hoses to join the copper line. I have a jubilee clip holding the flexible hose onto the copper pipe.

Pete

I had to look up "jubilee clip" to find that it is the classic marine or automotive screw-tightened hose clamp.

I'd be a great deal happier with mine, which is a hose-shop fabricated crimp connector.

And FWIW, I, too, have the regulator directly to the tank. Just one more hose connection to eliminate, also eliminating flex (ya, I know, hoses are supposed to flex) wear potential...