LP tank location?

[Bill Anglin]

Hi all,
As I understand it you need to have 10' clearance from a possible source of ignition. Does the motor on the hot tub break this rule? also, where do I find on the tank label how many gal the tanks are? Honestly I'm not real confident on my LP knowledge. Any help here is greatly appreciated.

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[Jerry Peck]

I believe it is 3 feet from a source of ignition (might be 5 feet, but I think it is 3 feet) and yes, the motor would be a source of ignition.

[John Kogel]

I think they are 260 pounders.
BBQ tanks are 20 pounders, the tall narrow tanks are 100 pounders. But I'm Canadian.

We have the same lbs, but our Imperial gallons are bigger. Anyway, this chart is from a US site. Liquid Propane is measured by weight.

[Bob Harper]

You have DOT cylinders and ASME containers, each with very different clearances as noted in the back of NFPA 58.

All tanks are rated in terms of water capacity by weight. Therefore, the ubiquitous "100lb" tank will hold 238lbs of water at about 8.25 lbs/ gal. That's full. Now, you never fill LP tanks more than 80% so the gas has room for expansion and vaporization. So, in actuality, that tank should hold a max of about 35 gallons or 97-100 lbs of fuel, hence the "100 lbs." rating. At a vapor density (usually erroneously referred to as 'specific gravity') of 1.50, a 100 lb tank will hold about 2,154,800 BTUs of LP (which stands for 'liquified petroleum--not liquid propane) fuel. However, you should never run an LP tank down below 20% so really only about 1,939,320 BTUs of available fuel.

Except for small salamander construction heaters and such, 100lb. tanks are not good for much and almost always undersized for fixed installations such as residences due to the poor vaporization rate.

[Bill Anglin]

Wow! 3 responses from 3people I know are very knowledgeable. Do any of you see any problems in the photos that should be described in the report? Thanks for the help

[Jerry Peck]

If I am reading the label correctly, those tanks are 120 gallon water capacity.

The first thing I noticed is that they are on three separate pads, and I would think (but do not know for sure) that each tank should be on one support pad (Bob Harper would likely know if that was the case or not).

Other than ignition source clearance (which I can't tell from the photo), the clearance between the tank valves and the window/building opening looks like it meets the 5 feet needed.

I can't tell much else from the photos, so hopefully Bob (who knows a whole lot more than I do about LPG tanks and LPG installation requirements) will address what he sees.

[Robert Ernst]

Tanks here have to be 10' from any structures, ignition, source, or intake vent.

[John Kogel]

Wow! 3 responses from 3people I know are very knowledgeable. Do any of you see any problems in the photos that should be described in the report? Thanks for the help

There's no visible problem that I can see from here. The tops of those fatboys are almost 5 feet from the ground. Check with your local authority.

I see tanks that size parked up against the house all the time. Larger tanks are generally given some space. A general rule is to orient the ends of the blimp away from nearby structures, because when they blow, they blow out one end like a cannon.

"Liquified petroleum". Thanks, Bob.

[Jerry Peck]

Tanks here have to be 10' from any structures, ignition, source, or intake vent.

*ALL* tanks, even those small BBQ gas grill size tanks?

The clearances and locations change based on the size of the tank or the total aggregate size of all tanks located together, and whether buried or above ground.

[Bob Harper]

There are two factors that determine the minimum clearance for LP tanks:
location during filling and whether DOT cylinder vs. ASME container.

Basicallly, the valve needs to be 10 feet away from an ignition source when filled on site. You can place portable LP cylinders closer but they cannot be filled if less than 10' from an ignition source.

You can read the full text online for free or buy the entire 2011 version. I recommend with any code you buy the commentary version or in this case, the 'Handbook'. Also note that NFPA has been including interpretations in the back of the latest code book plus they are online, which can clear up many issues. For instance, they ruled that a dryer vent exhaust is considered a building opening in their book.

HTH

[Bob Knauff]

Perhaps this will help.

[steve noel]

Hi all,
As I understand it you need to have 10' clearance from a possible source of ignition. Does the motor on the hot tub break this rule? also, where do I find on the tank label how many gal the tanks are? Honestly I'm not real confident on my LP knowledge. Any help here is greatly appreciated.

The tanks need to be postioned on solid footing... either one large pad or individual pads.

Yes... an electrical motor is considered a source of ignition, this would be an illegal install.

The tanks you have are called 120's (gallons) or 420's(pounds), each would be filled to an 80% capacity to allow for expansion of the propane.

All ASME tanks will have a metal plate with the information you request, DOT tanks will have this stamped into the metal.

DOT tanks need to be hydrostatically tested every 12 years... ASME tanks never have to be tested.

Any tank filled on site needs to be 10 feet from any ignition source, dryer vents, disconnects, motors that are non explosion proof, A/C etc.
my guess would be that the motor in question is non explosion proof, is thatan electrical box on the side of the house?

The gas piping you took a picture of with the thermacel insulation is concerning... what kind of tubing is this.

Is the protective insulation UV protected... if not, it's illegal.

In exterior application all trac pipe, gas tite, and ward flex should have their protective coating intact and flexible tubing should be covered with a special tape provided by the manufacturer.

Hope this helps.

[Garry Blankenship]

Good thread for me at least. I recently had some LP work done @ my home and trying to keep up w/ all the regs and limitations is tough - - - especially when you get it all in one gulp. The legally required distances changed with the tank size, one distance for windows, another for potential ignition sources, different tank "certifications" and like any other code/s AHJ requirements can differ. I found it particularly odd the the common 100 gallon tanks, ( 120 gal ? ), could be next to the structure, while anything bigger could not. Even odder that you could gang up the 100's and still stay next to the structure. Lots to learn.

[steve noel]

Good thread for me at least. I recently had some LP work done @ my home and trying to keep up w/ all the regs and limitations is tough - - - especially when you get it all in one gulp. The legally required distances changed with the tank size, one distance for windows, another for potential ignition sources, different tank "certifications" and like any other code/s AHJ requirements can differ. I found it particularly odd the the common 100 gallon tanks, ( 120 gal ? ), could be next to the structure, while anything bigger could not. Even odder that you could gang up the 100's and still stay next to the structure. Lots to learn.

You won't find it odd, if you have to move a full 120 which weights nearly 700 pounds.

The others would weigh too much to readily move in an emergency situation.

[Chris Loiacono]

You won't find it odd, if you have to move a full 120 which weights nearly 700 pounds.

The others would weigh too much to readily move in an emergency situation.

I know this is an old thread, but I find myself in a similar situation.

How is the 5 ft rule applied to a 120/100 gal tank near the corner of a home with an opening around the corner- such as at the side of a garage?

[Roy Lewis]

I know this is an old thread, but I find myself in a similar situation.

How is the 5 ft rule applied to a 120/100 gal tank near the corner of a home with an opening around the corner- such as at the side of a garage?

[Jerry Peck]

Like the attached drawing shows.

A tank that size will be filled on-site from a bulk truck.

[Chris Loiacono]

Like the attached drawing shows.

A tank that size will be filled on-site from a bulk truck.

Yes, I understand. My question is more about how the distance is figured. In order to place the fill valve and PRV 10 feet from an electric meter (source of ignition, if I'm not mistaken), it will be 4 ft from the end of the garage wall. The opening on the adjoining side of the garage wall is 2 feet from the corner. Is this considered to be 6 feet from the opening?

[Jerry Peck]

Yes, I understand. My question is more about how the distance is figured. In order to place the fill valve and PRV 10 feet from an electric meter (source of ignition, if I'm not mistaken), it will be 4 ft from the end of the garage wall. The opening on the adjoining side of the garage wall is 2 feet from the corner. Is this considered to be 6 feet from the opening?

I'll rephrase what you said to reflect what I think you are asking about: draw the house wall/corner on a piece of paper, locate the tank on the drawing, then make a 5 foot radius circle from the fill valve/relief valve cover (where gas from the escape from an opening in that cover), the 5 feet is "is any direction", thus drawing the 5 foot radius circle.

If an opening or ignition source is within that circle, then the two are too close, and don't forget, if the tank is filled on-site (as a 120 gallon tank would be), then the distance to an ignition source is 10 feet, not 5 feet. The 5 feet is to an opening.

[Chris Loiacono]

I'll rephrase what you said to reflect what I think you are asking about: draw the house wall/corner on a piece of paper, locate the tank on the drawing, then make a 5 foot radius circle from the fill valve/relief valve cover (where gas from the escape from an opening in that cover), the 5 feet is "is any direction", thus drawing the 5 foot radius circle.

If an opening or ignition source is within that circle, then the two are too close, and don't forget, if the tank is filled on-site (as a 120 gallon tank would be), then the distance to an ignition source is 10 feet, not 5 feet. The 5 feet is to an opening.

Got it. Thanks. I have an overhead view drawn in AutoCAD. I'll add the circle with 5' radius to see if it's a good location.

[Jerry Peck]

In order to place the fill valve and PRV 10 feet from an electric meter (source of ignition, ...

I have an overhead view drawn in AutoCAD. I'll add the circle with 5' radius to see if it's a good location.

Source of ignition is 10 feet, not 5 feet.

[William Reilly]

I have several concerns about this installation. Was it permitted and done by a licensed plumber? Do we assume there is a pressure regulator? Is the connection between the tubing and the CSST an approved connection? What is the status of the electrical bonding of the gas piping? Is there dielectric isolation where required? I don't know about Spokane, and not trying to be an alarmist, but with the lightning storms we have, I would be very uneasy with this arrangement.

[Gunnar Alquist]

This is a handy resurrection of this thread because an LP tank location question was asked on another inspector BB and it's something that I have not run into.

Basically, a homeowner chose to switch LP service providers, but when it came time to install the new tank (since the previous was rented and owned by the competition, it required replacement), the new supplier notified the owners that the location had to be moved due to the overhead electrical service drop.

It looks like NFPA 58 covers LP tank installation, but I don't have that publication. Does anyone know the specific requirements for LP tank placement. Not the DOT tanks, but the large ASME tanks.

Thanks.

[Jerry Peck]

Gunnar,

Above ground or below ground/in ground?

The document I posted addresses both types of tanks installed above ground.

I have another similar document which addresses below ground/in ground tanks that I can post when I get back to my office if you need it.

[Gunnar Alquist]

Hi Jerry,

Above-ground tank. In the document you posted, I see the 10 foot from source of ignition, but does that really include overhead electrical service drop? A service drop, even if it is less than 10 feet above the tank (which would be more like 13 feet above grade) shouldn't emit sparks like a motor or engine would. I didn't see anything else that would qualify in that particular document.

But then again, I'm tired.

[Jerry Peck]

Hi Jerry,

Above-ground tank. In the document you posted, I see the 10 foot from source of ignition, but does that really include overhead electrical service drop? A service drop, even if it is less than 10 feet above the tank (which would be more like 13 feet above grade) shouldn't emit sparks like a motor or engine would. I didn't see anything else that would qualify in that particular document.

But then again, I'm tired.

Gunnar,

It is alomst comical that they would point UP to an overhead service drop line as a source of ignition, but ... I have seen, and I am sure that many of us have seen, overhead service drops which has arcing between the uninsulated neutral and the burned-through insulated ungrounded conductors, so ... I'll buy their position that an overhead service drop could ... could ... be a source of ignition.

But ... they are not applying those clearances as stated.

Distances to building openings, as noted in 6.3.8, are measured horizontally.

Distances to sources of ignitions, as noted in 6.3.9, are measured in any direction - so unless the tank was immediately below the drip loop or within a foot or two of it, any overhead service drop would not meet the minimum of minimum heights above grade (10 foot minimum to the drip loop, which would also be the lowest point crossing a yard, and if that yard is not fenced and is not subject only to pedestrian traffic, then the minimum height is 12 feet ... except at the drip loop).

That would mean 'don't bother relocating the tank, the overhead service drop needs to be raised higher to meet minimum clearances.

If the overhead service drop meets minimum requirements and the tank is not directly below the drip loop (i.e., the clearance above grade to the overhead service drop is 12-1/2 to 13 feet or so), then there would be 10 feet clearance from the overhead service drop to the area of the tank being measured to (the top of the tank likely being about 2-1/2 to 3 feet high unless it is a vertical tank).

If it is a vertical tank, where the top could be 4 feet or so high, then it is easier to visualize that a tank might not make that 10 foot clearance to the overhead service drop source of ignition ... but all that would be needed would be to move the tank a foot or so as the measurement is not horizontal, the measure measurement is like the radius of a circle "in any direction from the point" ... which would be any opening in a closed surround or top over the actual point as gas could escape through any opening.

I am attaching the document for underground storage tanks in case you need it in the future.

Changing gas suppliers when underground tanks are present does raise several issues - as you said, the new gas supplier will insist on installing THEIR tank (the don't want to take responsibility for someone else's tank, I don't blame them either).

First, the old tank needs to be pulled from the ground (not left 'abandoned' below ground.

Then the new gas supplier needs to move that old tank out of the way to where it is not a hazard (there could be gas left in the tank, so leaving it on-site is a hazard, but moving it off-site is stealing someone else's tank).

Then the old gas supplies needs to come and remove THEIR tank from the property and take it back to their place of storage, and they have no incentive to do that as they will not get paid for doing that.

The solutions for the AHJ which I worked for was, for gas permits like that, to require, as a condition of the permit, that no hazard be left on-site ... that puts the onus on the new company to have the old company remove the tank pronto. And another condition of a gas permit was that no new gas permits would be issued to gas companies which left hazardous conditions in place ... and not removing their old tank pronto leaves a hazardous condition in place, so they typically would respond relatively quickly to get their old tanks - especially if they had any gas permits coming up soon. It's a tough position for the AHJ as they are limited in what they can do and enforce, but they need to do what they can to make sure that the old tank is not left on-site as a hazard. I've seen where large signs with the offending gas supplier's name were posted on the tank warning all persons that the tank was hazardous ... the offending gas supplier gets calls about "the hazard" from their clients ('do I have a hazard at my house too?') and then they call the AHJ, which says that the sign will be removed when the hazard is removed ... i.e.., 'come and get your friggin' tank and your problem will go away' ... works most of the time.

[Gunnar Alquist]

Thanks Jerry,

I did finally get online to NFPA 58 this morning and found this:

6.25 Ignition Source Control
6.25.2.1 Electrical equipment and wiring installed in unclassified areas shall be in accordance with NFPA 70
6.25.2.2 The extent of electrically classified areas shall be in accordance with Table 6.25.2.2

Table 6.25.2.2 then goes on to describe location, extent of classified area and division. For our purposes:

Location Part A: Unrefrigerated containers other than cylinders and ASME vertical containers of less than 1000 lb (454 kg) water capacity.

Extent of Classified Area Within 15 ft (4.6 m) in all directions from connections, except connections otherwise covered in this table.

Approved for Compliance with NFPA 70, National Electrical Code Class 1, Group D, Division 2

6.25.2.4 The provisions of 6.25.2.2 shall not apply to fixed electrical equipment at residential or commercial installations of LP-Gas systems or to systems covered by Section 6.26

OK, so a few thoughts. First, I cannot find any Class 1, Group D Division 2 in the NEC (no Division 2). Second, the hazardous classified area around the tank appears to be 15 feet in all directions. Third, 6.25.2.4 seems to negate the table's requirements for residential installation.

So, if I understand all of this correctly, it looks to me like we are back to the minimum height of the service drop. I don't know about anyone else, but my brain hurts. Best bet is to disclaim all parts of LP storage and defer to the supplier.

[Jerry Peck]

Gunnar,

That's where the internet and Google searches come in handy.

https://www.gasteconline.com/tank-chart.php

Location Part A: Unrefrigerated containers other than cylinders and ASME vertical containers of less than 1000 lb (454 kg) water capacity.

From that link above: (underlining is mine)

420-pound Propane Tanks

Common Uses: Home heating, hot water, dryers, fireplaces, generators, pool heat.


Commercial Uses: Heating, commercial cooking, dry cleaning and temporary heating.


Size and Capacity: This tank is approximately 4 feet tall by 3 feet diameter and will hold 100 gallons when filled to 80 percent capacity.


Notes: These tanks are commonly referred to by a few different names. Such names include "100 gallons,” which refers to the actual number of gallons of propane the tank can hold; "120 gallons," which refers to the total water capacity of the tank; and a "420lb tank,” which refers to the number of pounds of propane the tank will be able to hold when filled to 80 percent.


Placement Restrictions: The minimum distance from a door or window into building is 5 feet. The minimum distance from a source of ignition is 10 feet. Up to 4 of these tanks are permitted to be placed next to each other, assuming the other restriction clearances are met.

Thus, a 120 gallon vertical container falls under the "other than cylinders and ASME vertical containers of less than 1000 lb" exception ("other than") of that requirement.

Then you go down to D ("within 5 ft", and E ("within direct path of discharge"), and to K ("Outdoors in open air" and "within 5 ft" and "Beyond 5 ft ... but within 15 ft".


However, we need to define "cylinder", the definitions say:
- 3.3.17 Cylinder. A portable container with a marked water capacity of 1000 llb (454 kg) or less that is designed to transport and store LP-Gas.


Which means we have to define "container", 3.3.14 says:
- 3.3.14 Container. Any vessel, including cylinders, tanks, portable tanks, and cargo tanks, used for transporting or storing LP-Gas.

The catch, though, is that it refers to "vertical" containers, but does not define what "horizontal" or "vertical" is.

The drawing I posted is from a few years ago, the section numbers have changed - Table 6.3.8 is not Table 6.4.4.3.

Section 6.3.9 on my page is now 6.4.4.4 and references Table 6.4.4.3.

Section 6.3.8 on my page is now 6.4.4.3 and references Table 6.4.4.3.

So ... I would say that puts you back to the distances in 6.4.4.4 (old 6.3.8); 6.4.4.4 (old 6.3.9) and Table 6.4.4.3 (old Table 6.3.8) and ... you are right on it ... NFPA 70 (the NEC) for overhead service drop clearances.

The first thing which must be met is the overhead service drop clearances. (I put this as the first things because, even if no LP gas tank is present, this is required.)

The second thing which must be met are the clearances from openings and ignition sources.

The third thing to check is the overlap of the two above items as it is possible (but not likely) that the tank could be within the clearance to ignition sources of an overhead service drop which has proper clearances above grade.

Move the LP gas tank to clear the overhead service line? If so, then that overhead service line is likely not high enough (keeping in mind that the right - er ... wrong - exact location of a tank could create a conflict with the overhead service drop.

[Jerry Peck]

I was looking around for a clarification of "vertical" cylinders/containers/tanks (other than the obvious that the tank itself sets upright vertically) and found this: http://www.scfiremarshal.llronline.c.../SecondQtr.pdf (I didn't read the entire document, I just skimmed through parts of it, but even that provided good information)

It contains good information on LP gas cylinders and tanks (containers), especially this part:

- (file page 51/216) - (shows what we typically think of as "cylinders")
- - - "DOT Containers aka… Cylinders"


- (file page 57/216)
- - (shows what we typically think of as "tanks")
- - - "ASME Containers, API-ASME Containers aka… Bulk Containers "

[Gunnar Alquist]

Hi Jerry,

Thanks. It's going to take me a while to go through this stuff.

[Jerry Peck]

Gunnar,

I was reading back through our posts and this caught my eye as maybe being to solution to the 15 ft clearance:

(underlining is mine)

6.25 Ignition Source Control
6.25.2.1 Electrical equipment and wiring installed in unclassified areas shall be in accordance with NFPA 70
6.25.2.2 The extent of electrically classified areas shall be in accordance with Table 6.25.2.2

Table 6.25.2.2 then goes on to describe location, extent of classified area and division. For our purposes:

Location Part A: Unrefrigerated containers other than cylinders and ASME vertical containers of less than 1000 lb (454 kg) water capacity.

Extent of Classified Area Within 15 ft (4.6 m) in all directions from connections, except connections otherwise covered in this table.

That "except connections otherwise covered in this table is a key, as:

Then you go down to D ("within 5 ft", and E ("within direct path of discharge"), and to K ("Outdoors in open air" and "within 5 ft" and "Beyond 5 ft ... but within 15 ft".

D and K are "except connections otherwise covered in this table", and that reduces (for the most part) down to 5 ft.

I would need to go back and re-read that stuff, but the "except connections otherwise covered in this table" removes everything covered in the table from that blanket clearance requirement.

At least it makes it less to read through.

[Gunnar Alquist]

One of my big complaints about many of the codes is the lack of reasons/explanations regarding intent. In this case, it seems like the gas supplier may have misinterpreted the code. If explanations were provided, then misinterpretations might happen less. Then again, some codes are intended to be broad, in order to prevent something from "getting by" simply because a specific condition or item was not specified.

I haven't had time to read this again, but I will. Thanks Jerry.

[Gunnar Alquist]

I just got another update. It kind of comes in dribbles. Frustrating, I know.

So, it seems that the issue was not due to the height or proximity of the service drop, it is about the lines between utility poles and their distance from the propane tank. Now, I am completely confused about this. If the utility company's lines are within 15' (NFPA 58 6.25) of the tank (classified area), then the lines are too low and should be raised. If they are the proper height, then how is the tank within 15'?

Unless the 15' clearance in all directions requirement has to do with keeping 15' away from a vertical line below the lines on the pole (above 600 volts). This kind of makes sense. If the lines were to drop and a propane tank was directly below, then this could be a problem. It might be necessary to have the tank a minimum of 15' from the "drop zone".

I also need help with terminology here. Please verify or correct me.
Transmission Lines = Ridiculously high voltage (like 100,000+ volts) on the giant towers. These are generally not in neighborhoods, but supply power to the substations where it is stepped-down to medium (but still high) voltages.
Primary Distribution Lines = Medium voltage (like 10,000 volts) on the upper portion of the poles that deliver the power from the substations to the neighborhoods where transformers step-down the power again.
Utilization Lines = Household voltages (240) after the pole-mounted transformers that distribute power to the service drops.

Did I get it right?

[Jerry Peck]

So, it seems that the issue was not due to the height or proximity of the service drop, it is about the lines between utility poles and their distance from the propane tank. Now, I am completely confused about this. If the utility company's lines are within 15' (NFPA 58 6.25) of the tank (classified area), then the lines are too low and should be raised. If they are the proper height, then how is the tank within 15'?

(underlining is mine)

6.25 Ignition Source Control
6.25.2.1 Electrical equipment and wiring installed in unclassified areas shall be in accordance with NFPA 70
6.25.2.2 The extent of electrically classified areas shall be in accordance with Table 6.25.2.2

Table 6.25.2.2 then goes on to describe location, extent of classified area and division. For our purposes:

Location Part A: Unrefrigerated containers other than cylinders and ASME vertical containers of less than 1000 lb (454 kg) water capacity.

Extent of Classified Area Within 15 ft (4.6 m) in all directions from connections, except connections otherwise covered in this table.

That "except connections otherwise covered in this table is a key, as:

Then you go down to D ("within 5 ft", and E ("within direct path of discharge"), and to K ("Outdoors in open air" and "within 5 ft" and "Beyond 5 ft ... but within 15 ft".

D and K are "except connections otherwise covered in this table", and that reduces (for the most part) down to 5 ft.

I would need to go back and re-read that stuff, but the "except connections otherwise covered in this table" removes everything covered in the table from that blanket clearance requirement.

Unless the 15' clearance in all directions requirement has to do with keeping 15' away from a vertical line below the lines on the pole (above 600 volts). This kind of makes sense. If the lines were to drop and a propane tank was directly below, then this could be a problem. It might be necessary to have the tank a minimum of 15' from the "drop zone".

Except that it says "in any direction", which means you start at the point being addressed (such as the valve) and apply a 15' radius from that point out in all directions.

Clearances for openings are measured horizontally, which is what your "drop zone" would be.

I also need help with terminology here. Please verify or correct me.
Transmission Lines = Ridiculously high voltage (like 100,000+ volts) on the giant towers. These are generally not in neighborhoods, but supply power to the substations where it is stepped-down to medium (but still high) voltages.
Primary Distribution Lines = Medium voltage (like 10,000 volts) on the upper portion of the poles that deliver the power from the substations to the neighborhoods where transformers step-down the power again.
Utilization Lines = Household voltages (240) after the pole-mounted transformers that distribute power to the service drops.

Did I get it right?

This is PGE glossary of terms:

https://www.pge.com/includes/docs/pd...k/glossary.pdf

https://www.pge.com/includes/docs/pd...orks/gloss.pdf

[Gunnar Alquist]

Hi Jerry,

I guess I am being excessively dim, but I am just not getting it. I read your earlier post as well as my own. I understand the 15 foot diameter, but are you pointing out the "within direct path of discharge"? Is that the "drop zone"?

[Jerry Peck]

Gunnar,

I'm probably the dim one not being able to communicate what I'm thinking, or maybe the two of us together can replace the need for a nightlight ...

Your "drop zone" would be applying a vertical line point for a horizontal measurement. Horizontal measurements are applied to building openings from the propane container point.

Sources of ignition are measured spherically (is that a word?) around/from a container point.

'Normal condition' 'ignition source' clearance is 3 feet (or is it 5 feet) from the fill valve/other point.

'Fill condition' (while filling, but applied to all fixed objects all the time because they are not movable during filling operations) is 10 feet. That distance allows for dilution of the propane to below ignition concentration as it moves further from the propane source.

That 'fill condition' distance would not apply to power lines laying on the ground because no one in their right mind would fill a propane tank with a downed power line that close ... at least not an energized downed power line.

So I'm not sure where they are getting there 15 feet from - other than from not reading the table beyond that first statement of 15 feet ... not bothering to read the 'except as otherwise permitted in this table'.

Either that or I am missing something in that table, and they don't understand enough about that table to decisively point to what they are referring to.

[Gunnar Alquist]

Let's see if I finally got this right.

So, in 6.25.2.2 A, we have a required 15' distance in all directions from connections (except for the exceptions). Presumably, these are connections to the gas system? It seems like that would not be referring to electrical connections (splices, etc.), but I don't see a specific definition. So, this would be a spherical measurement from any point on the tank from which gas could leak (valve, fill point, relief valve). If I understand this correctly, it seems perfectly reasonable. You want the gas to be able to dissipate before it reaches a source of ignition to prevent fire/explosion.

From Post #28 above:

Then you go down to D ("within 5 ft", and E ("within direct path of discharge"), and to K ("Outdoors in open air" and "within 5 ft" and "Beyond 5 ft ... but within 15 ft".

So, what are "point of discharge", "source of discharge" and "path of discharge" referring to? Would this be referring to a discharge of gas from the tank (valve, fill point and relief valve)? I just want to make sure it is not some euphemism for source of ignition (spark or electrical discharge). Below, you state "container point", which might indicate any point on a container rather than a source that is more likely to leak (valve).

In any case, in my example, the tank, point, source and path of discharge are well away from any permanent source of ignition, whether 5, 10 or 15 feet.

Your "drop zone" would be applying a vertical line point for a horizontal measurement. Horizontal measurements are applied to building openings from the propane container point.

My problem is that in the particular case that I brought up, there doesn't seem to be a source of ignition, unless the utility wires were to fall. But, as you said, no one would fill a tank if there were arcing utility wires lying on the ground (at least I hope not). I could see a potential problem if distribution lines fall directly on the tank. Is this really what they are getting at? But, if I were to take this to an absurd conclusion, what if the pole were to fall? Then, our distance would have to include the height of the pole and any place it could fall and drop it's lines (what is that, 40-50 feet?). In my ridiculous case, that would mean the tank would have to be really far away.

Sources of ignition are measured spherically (is that a word?) around/from a container point.

Once again, is that any point on the container or only those points that are likely to leak gas (valve, fill point, relief)?

This whole thing is from a home inspector in the San Diego area and, unfortunately, getting specific information out of him is kind of difficult. The last message I received is that he talked to someone at a propane supply company in the area and they referred to a 10 foot rule. My head hurts.

I think, in the end, this is something that is well outside of the area of a home inspector's knowledge and expertise. My contract disclaims the tank and puts the onus on the tank's owner (in this case, the propane company). I just don't fully understand how this was installed like this originally if it is such a big problem today. Of course, we just had some impressive fires in my area, so we might end up seeing even more changes to various codes.

Yes, spherically is a word.

Jerry,

Thank you for all of your help. This has been frustratingly interesting.

[Jerry Peck]

Gunnar,

For the "location" of tank (from buildings, property lines, etc) where applicable, the "location" is measured from the closest part of the tank, i.e, measured from the closest end of the tank to a property line, building, etc.

For "clearance" from openings into a building and ignition sources, the measurements are taken from the point specified in those drawings I posted, see Table 6.3.8.