El efecto moderador de las variables psico-sociodemográficas en la relación

Containers installed outside of buildings, whether of the portable type replaced on a cylinder exchange basis or permanently installed and refilled at the installation, shall be located with respect to the nearest container, important building, group of buildings, or line of adjoining property that can be built upon, in accordance with the following and Table 13.4-a, and Table 13.4-c.

(1) At a consumer site, if the aggregate water capacity of a multicontainer installation comprised of individual containers having a water capacity of less than 125 gal (0.5 m3) is 501 gal (1.9 m3) or more, the minimum distance shall comply with the appropriate portion of Table 21-3.1.1.1, applying the aggregate capacity rather than the capacity per container. If more than one such installation is made, each installation shall be separated from any other installation by at least 7.6 m. The minimum distances between containers shall not be applied to such installations.

Table 13.4-a

Water Capacity per Container gallons (m3)

Minimum Distances

m

Mounded or Underground Containers

Aboveground Containers Between Containers

Less than 125 (0.5) 3 None None

125 to 250 (0.5 to 1.0) 3 3 None

251 to 500 (1.0+ to 1.9) 3 3 1

501 to 2,000 (1.9+ to 7.6) 3 7.6 1

2,001 to 30,000 (7.6+ to 114) 15 15 1.5

*One-quarter of the sum of the diameters of adjacent containers.

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(2) Cylinders installed alongside of buildings shall be located and installed so that the discharge from the cylinder pressure relief device is at least 1 m horizontally away from any building opening that is below the level of such discharge. Cylinders shall not be located and installed underneath any building unless the space is not enclosed for more than 50 percent of its perimeter. The discharge from container pressure relief devices shall be located not less than 1.5 m in any direction away from any exterior source of ignition, openings into direct-vent (sealed combustion system) appliances, or mechanical direct-ventilation air intakes.

(3) The distance measured horizontally from the point of discharge of a container pressure relief valve to any building opening below the level of such discharge shall be in accordance with Table 13.4-b.

(4) The distance measured in any direction from the point of discharge of a container pressure relief valve, the vent of a fixed maximum liquid level gauge on a container, or the installed location of the filling connection of a container to any exterior source of ignition, openings into direct-vent (sealed combustion system) appliances, or mechanical ventilation air intakes shall be in accordance with Table 13.4-b.

(5) The 7.6 m distance from aboveground containers of 501 gal to 2,000 gal (1.9 m3 to 7.6 m3) capacity to buildings, group of buildings, or line of adjoining property that can be built upon shall be permitted to be reduced to not less than 3 m for a single container of 1,200 gal (4.5 m3) water capacity or less provided such container is at least 7.6 m from any other LP-Gas container of more than 125 gal (0.5 m3) water capacity.

Table 13.4-b

Discharge from Relief Valve, Vent Discharge, and Filling Connection to Exterior Source of Ignition, Openings into Direct-Vent

Appliances, Mechanical Ventilation Air Intakes m

Cylinder Exchange 1 1.5

Cylinder Filled on site 1 3

ASME Filled on site 1.5 3

(6) Minimum distances for underground or mounded ASME containers of 2,001 gal through 30,000 gal (7.6 m3 through 114 m3) water capacity incorporating all the provisions of NFPA 58 shall be permitted to be reduced to 3 m. Distances for all underground and mounded ASME containers shall be measured from the relief valve and the filling connection. No part of an underground ASME container shall be less than 3 m from a building or line of adjoining property that can be built upon, and no part of a mounded ASME container that is installed above grade shall be less than 1.5 m from a building or line of adjoining property that can be built upon.

(7) Where underground multi-container installations are made of individual containers having a water capacity of 125 gal (0.5 m3) or more, such containers shall be installed so as to permit access at their ends or sides to facilitate working with cranes or hoists.

(8) In applying the distance between buildings and ASME containers of 125 gal (0.5 m3) or more water capacity, a minimum of 50 percent of this horizontal distance shall also apply to all portions of the building that project more than 1.5 m from the building wall and that are higher than the relief valve discharge outlet. This horizontal distance shall be measured from a point determined by projecting the outside edge of such overhanging structure vertically downward to grade or other level upon which the container is installed. Under no condition shall the distances to the building wall be less than those specified except when the provisions of NFPA 58 are met. These distances shall be permitted to be reduced by one-half for ASME containers of 2,001 gal through 30,000 gal (7.6 m3 through 114 m3) water capacity used in systems complying with Section of NFPA 58.

Underground or mounded containers shall be located outside of any buildings. Buildings shall not be constructed over any underground or mounded containers. Sides of adjacent containers shall be separated in accordance with Table 13.4-a but not less than 1 m.

Where containers are installed parallel with ends in line, any number of containers shall be permitted to be in one group. Where more than one row is installed, the adjacent ends of the tanks in each row shall be separated by not less than 3 m.

The following provisions shall also apply:

(1) Containers shall not be stacked one above the other.

(2) Loose or piled combustible material and weeds and long dry grass shall not be permitted within 3.0 m of any container.

(3) Means shall be used to prevent the accumulation or flow of liquids having flash points below 93.4°C under adjacent LP-Gas containers such as by dikes, diversion curbs, or grading.

(4) LP-Gas containers shall be located at least 3.0 m from the centerline of the wall of diked areas containing flammable or combustible liquids.

(5) The minimum horizontal separation between aboveground LP-Gas containers and aboveground tanks containing liquids having flash points below 93.4°C shall be 6 m. No horizontal separation shall be required between aboveground LP-Gas containers and underground tanks containing flammable or combustible liquids installed in accordance with NFPA 30, Flammable and Combustible Liquids Code.

(6) The minimum separation between LP-Gas containers and oxygen or gaseous hydrogen containers shall be in accordance with Table 13.4-c of this document.

(7) The minimum separation between LP-Gas containers and liquefied hydrogen containers shall be in accordance with NFPA 50B, Standard for Liquefied Hydrogen Systems at Consumer Sites.

(8) Where LP-Gas containers are to be stored or used in the same area with other compressed gases, the containers shall be marked to identify their content in accordance with ANSI/CGA C-4, Method of Marking Portable Compressed Gas Containers to Identify the

Separation from Oxygen Containers Aggregate Capacity

*m3 measured at 21°C and atmospheric pressure.

Structures such as fire walls, fences, earth or concrete barriers, and other similar structures, shall be avoided around or over installed non-refrigerated containers.

Containers shall be installed in accordance with the following:

(1) Cylinders shall be installed only aboveground, and shall be set upon a firm foundation or be otherwise firmly secured. Flexibility shall be provided in the connecting piping.

(2) All containers shall be positioned so that the pressure relief valve is in direct communication with the vapor space of the container.

(3) Where physical damage to LP-Gas containers or systems of which they are a part, from vehicles is a possibility, precautions shall be taken against such damage.

(4) The installation position of ASME containers shall make all container appurtenances accessible for their normally intended use.

(5) Field welding on containers shall be limited to attachments to non-pressure parts, such as saddle plates, wear plates, or brackets applied by the container manufacturer.

(6) Aboveground containers shall be kept properly painted.

Provision shall be made in piping including interconnecting of permanently installed containers, to compensate for expansion, contraction, jarring and vibration, and for settling.

Where necessary, flexible connectors complying with NFPA 58 shall be permitted to be used.

The use of nonmetallic pipe, tubing, or hose for permanently interconnecting such containers shall be prohibited.

Underground metallic piping shall be protected against corrosion as warranted by soil conditions.

LP-Gas piping shall not be used as a grounding electrode.

Hose shall be permitted to be used on the low-pressure side of regulators to connect to other than domestic and commercial appliances as follows:

(1) The appliance connected shall be of a portable type.

(2) For use inside buildings, the hose shall be of a minimum length, not exceeding 1.8 m, and shall not extend from one room to another nor pass through any partitions, walls, ceilings, or floors. It shall not be concealed from view or used in concealed locations. For use outside buildings, hose length shall be permitted to exceed 1.8 m but shall be kept as short as practical.

(3) Hose shall be securely connected to the appliance.

(4) A shutoff valve shall be provided in the piping immediately upstream of the inlet connection of the hose. Where more than one such appliance shutoff is located near another, precautions shall be taken to prevent operation of the wrong valve.

(5) Hose used for connecting appliances to wall or other outlets shall be protected against physical damage.