CNG vs. Propane

[CTimmons]

Your thoughts Gord,

To avoid Bob's problem w/ taking up extra space because of the need to place directly under the lazarette lid, while meeting the spec., that locker opens as close to laz. opening as possible., I have thought about a sliding shelf or track that would slide out of the way and lock in place when closed, and slide out under the opening when there is a need to open the propane locker and service the tank. The vent hose could be carefully coiled so that it constantly vents down, but would provide sufficient length to move when needed. Thoughts?

 

[Fred Ficarra]

This subject will always come up and is,,

a product of our cultures' obsession with safety, propagated by law suite paranoia. Common sense should be the rule, not 'paragraph such and such' followed by 'sub rule whosenfetch'! If a person doesn't know how to do a job, like installing propane, then hire someone who does. Propane has a great safety record for a REASON(S). 1. It smells bad when leaking and not lit. 2. It is easy and compact to store. 3. It is relatively low pressure. A pressure gauge on a propane tank will only show a pressure drop during leak testing. A gauge is useless for determining how much fuel is left in the tank. Propane is a condensable gas. Put it under pressure and it liquefies. The pressure that this happens at is about <100psi. All of those new tank valves that are required to keep our tanks from being overfilled are BS. When is the last time a propane tank blew up from being overfilled? The pressure in a propane tank is the same whether filled to capacity or containing an eye dropper of liquid. Those overfill protection valves are required because a group of Bureaucrats needed (wanted) to do something to justify their existence and to feel like big shots so they came up with this 'new safety device'. They write the fire codes. My Fire Chief friend says 'that is what happens when you give too much power to too few people'.  Just look at the ABYC standards for the rest of your boat too. Remember when people used to build their own boat and go off into the sunset. Most sailors are too scared to do so now. Who created and backs the ABYC. I know that their standards are FOR SALE! Are they like UL? UL was and is a lab that is funded by the insurance industry to MINIMIZE their losses. Our safety is a public relations banter. Another example of this fear of, shall I call it, living life(?), is driving on our highways. Leave North America and see how the rest of the world does it. Here we have a paint strip to guide our every move. The result is that drivers never use their cars' accident evasion capability. We drive `by the numbers'. No one dares to have fun on the roads except hot rodders. (I'm one). When a hazard is in front of most drivers path, they react by hitting the brakes, not turning out of their lane. That is why antilock brakes didn't reduce our accident rate. You're also suppose to turn the WHEEL when you slam on the brakes! WHEW. I digress. I have been boarded by the Coast Guard several times. A few years ago they would actually look at your safety stuff instead of just searching for drugs. All of the boarding personnel look at my `non ABYC compliant' locker and say it is fine as long as it is vented overboard. They don't care about `loops' and `dips' or the location of your door/lid.  A while back I got in a `discussion' about propane at HOW and things got out of hand. Peggie and I didn't see eye to eye, but that's life. I went on about towing a burning Yacht out of Marina de LaPaz and what happened when the propane tank exploded. (not much) That fire, as most are, was caused by poor wiring, not propane. Anyhow, I just thought I'd fire up this site. It's been too quite this summer.

 

[Gord May]

Sliding Locker

CTimmons proposes a creative solution to the problem of installing an LPG locker, within a lazarette, so that it opens to the atmosphere; all while maintaining accessability to the lazarette for other purposes. A sliding locker shelf might do that, BUT, I wouldn’t know how to practically implement it:1 - A robust sliding system, such as described, might be somewhat difficult & complex in it’s design & fabrication. It might be just as easy to fabricate a new fixed locker & hatch in the lazarette’s quarter (corner). 2 - I cannot envision a ‘carefully coiled vent’ (& fuel supply) line that would:* Never develop a pocket depression that could trap vapors (in any position). It may be possible, but I think it might require a larger vertical decline, and horizontal clearance (bottom of locker to thru-hull discharge) than our freeboard might allow.* The appliance(s) fuel supply line would also require a slider loop.* It might be difficult to protect the vent & fuel lines from mechanical damage, and to "fix them in place" (free to move but fixed per code ?)3- The locker must be capable of quick, convenient opening, without tools (A-2.8.1.6). I’m don’t think that opening the lazaret hatch, removing obstructing gear from under lazarette hatch, unlocking, sliding & re-locking the locker slide, and then opening the locker lid would comply with the spirit of “quickly & conveniently”. Fred Ficarra advocates “common sense” over “code paragraph such & such”, and makes several other points. Let me add (deduct?):a - Unlike many other codes, “ABYC Standards & Recommended Practices” have no force in law. They purport to be only what the title implies. b - Adherence to ABYC, and other applicable codes & standards may limit a manufacturer/repairer’s liability. Doing so might indicate prudence and due diligence. A tradesman or DIY boatowner who ignores industry standards, does so at his own risk, assuming that he knows better than (most) others. c - “Common” sense is an oxymoron.d - Propane smells bad, because it has an odorous gas added (by law). The odor concentration varies, depending upon the volume of fuel remaining, and can be much less detectible under certain circumstances. You cannot absolutely rely on odour detection - it’s not infallible.e - Explosion is not the only hazard associated with propane. Though non-toxic, LPG will displace air; which could lead to asphyxiation.LPG gas is heavier than air, and sinks to the bottom of it’s enclosing compartment, and is not readily dispelled by normal ventilation. If properly mixed with air, & exposed to a source of ignition - it WILL explode & burn. Bob has experienced a propane explosion, where “not much happened”. Without knowing the details of the event, I still feel confident that he’s demonstrating a rather cavalier attitude towards safety.f - Pressure vessels have been regulated and tested since their very advent. Perhaps this is why you don’t hear of many ‘blow-ups” due to overfilling?g - The incompetance (no put-down intended) of some Coastguardsmen to fully inspect Fred’s non-compliant locker, has absolutely NO BEARING on the advisability of compliance with industry standard practices, codes, & etc. A major part of my current job is inspection (mechanical, plumbing, & electrical), and guess what ? There’s a lot of cunning tradesmen that can & do fool me on occasion. That I may not catch some deficiencies, does not relieve him of his responsibility to do it right. Hey, Fred, you did fire it up ... OMO, E. O. & E., without prejudice, and all the other “weasel clauses”Gord