TABLE H-23
Water capacity per container | Minimum distances | ||
Containers | Between aboveground containers | ||
Underground | Aboveground | ||
Less than 125 gals. 1 | 10 feet | None | None. |
125 to 250 gals | 10 feet | 10 feet | None. |
251 to 500 gals | 10 feet | 10 feet | 3 feet. |
501 to 2,000 gals | 25 feet 2 | 25 feet 2 | 3 feet. |
2,001 to 30,000 gals | 50 feet | 50 feet | 5 feet. |
30,001 to 70,000 gals | 50 feet | 75 feet. 3 | |
70,001 to 90,000 gals | 50 feet | 100 feet. 3 |
1 If the aggregate water capacity of a multi-container installation at a consumer site is 501 gallons or greater, the minimum distance shall comply with the appropriate portion of this table, applying the aggregate capacity rather than the capacity per container. If more than one installation is made, each installation shall be separated from another installation by at least 25 feet. Do not apply the MINIMUM DISTANCES BETWEEN ABOVE-GROUND CONTAINERS to such installations.
2 The above distance requirements may be reduced to not less than 10 feet for a single container of 1,200 gallons water capacity or less, providing such a container is at least 25 feet from any other LP-Gas container of more than 125 gallons water capacity.
3 1/4 of sum of diameters of adjacent containers.
Aluminum alloy tubing shall be protected against external corrosion when it is in contact with dissimilar metals other than galvanized steel, or its location is subject to repeated wetting by liquids such as water (except rainwater), detergents, sewage, or leakage from other piping, or it passes through flooring, plaster, masonry, or insulation. Galvanized sheet steel or pipe, galvanized inside and out, may be considered suitable protection. The maximum outside diameter for aluminum alloy tubing shall be three-fourths inch and shall not be used for pressures exceeding 20 p.s.i.g. Aluminum alloy tubing shall not be installed within 6 inches of the ground.
TABLE H-24-WALL THICKNESS OF COPPER TUBING 1
Standard size (inches) | Nominal outside diameter (inches) | Nominal wall thickness (inches) | |
Type K | Type L | ||
1/4 | 0.375 | 0.035 | 0.030 |
3/8 | 0.500 | 0.049 | 0.035 |
1/2 | 0.625 | 0.049 | 0.040 |
5/8 | 0.750 | 0.049 | 0.042 |
3/4 | 0.875 | 0.065 | 0.045 |
1 | 1.125 | 0.065 | 0.050 |
1 1/4 | 1.375 | 0.065 | 0.055 |
1 1/2 | 1.625 | 0.072 | 0.060 |
2 | 2.125 | 0.083 | 0.070 |
1 Based on data in Specification for Seamless Copper Water Tube, ANSI H23.1-1970 (ASTM B-88-69).
Note: The standard size by which tube is designated is 1/8 inch smaller than its nominal outside diameter.
TABLE H-25-WALL THICKNESS OF ALUMINUM ALLOY TUBING 1
Outside diameter (inches) | Nominal wall thickness (inches) | |
Type A | Type B | |
3/8 | 0.035 | 0.049 |
1/2 | 0.035 | 0.049 |
5/8 | 0.042 | 0.049 |
3/4 | 0.049 | 0.058 |
1 Based on data in Standard Specification for Aluminum-Alloy Drawn Seamless Coiled Tubes for Special Purpose Applications, ASTM B210-68.
Surface area (sq. ft.) | Flow rate CFM air |
20 or less | 626 |
25 | 751 |
30 | 872 |
35 | 990 |
40 | 1,100 |
45 | 1,220 |
50 | 1,330 |
55 | 1,430 |
60 | 1,540 |
65 | 1,640 |
70 | 1,750 |
75 | 1,850 |
80 | 1,950 |
85 | 2,050 |
90 | 2,150 |
95 | 2,240 |
100 | 2,340 |
105 | 2,440 |
110 | 2,530 |
115 | 2,630 |
120 | 2,720 |
125 | 2,810 |
130 | 2,900 |
135 | 2,990 |
140 | 3,080 |
145 | 3,170 |
150 | 3,260 |
155 | 3,350 |
160 | 3,440 |
165 | 3,530 |
170 | 3,620 |
175 | 3,700 |
180 | 3,790 |
185 | 3,880 |
190 | 3,960 |
195 | 4,050 |
200 | 4,130 |
210 | 4,300 |
220 | 4,470 |
230 | 4,630 |
240 | 4,800 |
250 | 4,960 |
260 | 5,130 |
270 | 5,290 |
280 | 5,450 |
290 | 5,610 |
300 | 5,760 |
310 | 5,920 |
320 | 6,080 |
330 | 6,230 |
340 | 6,390 |
350 | 6,540 |
360 | 6,690 |
370 | 6,840 |
380 | 7,000 |
390 | 7,150 |
400 | 7,300 |
450 | 8,040 |
500 | 8,760 |
550 | 9,470 |
600 | 10,170 |
650 | 10,860 |
700 | 11,550 |
750 | 12,220 |
800 | 12,880 |
850 | 13,540 |
900 | 14,190 |
950 | 14,830 |
1,000 | 15,470 |
1,050 | 16,100 |
1,100 | 16,720 |
1,150 | 17,350 |
1,200 | 17,960 |
1,250 | 18,570 |
1,300 | 19,180 |
1,350 | 19,780 |
1,400 | 20,380 |
1,450 | 20,980 |
1,500 | 21,570 |
1,550 | 22,160 |
1,600 | 22,740 |
1,650 | 23,320 |
1,700 | 23,900 |
1,750 | 24,470 |
1,800 | 25,050 |
1,850 | 25,620 |
1,900 | 26,180 |
1,950 | 26,750 |
2,000 | 27,310 |
Surface area=total outside surface area of container in square feet.
When the surface area is not stamped on the nameplate or when the marking is not legible, the area can be calculated by using one of the following formulas:
Area=Overall length*outside diameter* 3.1416.
Area=(Overall length+0.3 outside diameter) *outside diameter*3.1416.
Note: This formula is not exact, but will give results within the limits of practical accuracy for the sole purpose of sizing relief valves.
Area=Outside diameter squared*3.1416.
Flow Rate-CFM Air=Required flow capacity in cubic feet per minute of air at standard conditions, 60 F. and atmospheric pressure (14.7 p.s.i.a.).
The rate of discharge may be interpolated for intermediate values of surface area. For containers with total outside surface area greater than 2,000 square feet, the required flow rate can be calculated using the formula, Flow Rate-CFM Air=53.632 A0.82.
A=total outside surface area of the container in square feet.
Valves not marked "Air" have flow rate marking in cubic feet per minute of liquefied petroleum gas. These can be converted to ratings in cubic feet per minute of air by multiplying the liquefied petroleum gas ratings by factors listed below. Air flow ratings can be converted to ratings in cubic feet per minute of liquefied petroleum gas by dividing the air ratings by the factors listed below.
AIR CONVERSION FACTORS
Container type | 100 | 125 | 150 | 175 | 200 |
Air conversion factor | 1.162 | 1.142 | 1.113 | 1.078 | 1.010 |
The minimum required rate of discharge for safety relief valves shall be determined as follows:
TABLE H-26
Containers | Minimum (percent) | Maximum (percent) |
ASME Code; Par. U-68, U-69-1949 and earlier editions | 110 | 1 25 |
ASME Code; Par. U-200, U-201-1949 edition | 88 | 1 100 |
ASME Code-1950, 1952, 1956, 1959, 1962, 1965 and 1968 (Division I) editions | 88 | 1 100 |
API-ASME Code-all editions | 88 | 1 100 |
DOT-As prescribed in 49 CFR Chapter I |
1 Manufacturers of safety relief valves are allowed a plus tolerance not exceeding 10 percent of the set pressure marked on the valve.
When vaporizing and/or mixing equipment is located in a structure or building not used exclusively for gas manufacturing or distribution, either attached to or within such a building, such structure or room shall be separated from the remainder of the building by a wall designed to withstand a static pressure of at least 100 pounds per square foot. This wall shall have no openings or pipe or conduit passing through it. Such structure or room shall be provided with adequate ventilation and shall have a roof or at least one exterior wall of lightweight construction.
Ten feet for vaporizers having a capacity of 15 gallons per hour or less vaporizing capacity.
Twenty-five feet for vaporizers having a vaporizing capacity of 16 to 100 gallons per hour.
Fifty feet for vaporizers having a vaporizing capacity exceeding 100 gallons per hour.
Ten feet for storage containers of less than 500 gallons water capacity.
Twenty-five feet for storage containers of 500 to 1,200 gallons water capacity.
Fifty feet for storage containers of over 1,200 gallons water capacity.
Water capacity per container (gallons) | Minimum distances (feet) |
Less than 501 | 10 |
501 to 2,000 | 25 |
Over 2,000 | 50 |
TABLE H-27-MAXIMUM PERMITTED FILLING DENSITY
Specific gravity at 60 °F. (15.6 °C.) | Above ground containers | Under ground containers, all capacities | |
0 to 1,200 U.S. gals. (1,000 imp. gal., 4,550 liters) total water cap. | Over 1,200 U.S. gals. (1,000 imp. gal., 4,550 liters) total water cap. | ||
Percent | Percent | Percent | |
0 .496-0 .503 | 41 | 44 | 45 |
.504- .510 | 42 | 45 | 46 |
.511- .519 | 43 | 46 | 47 |
.520- .527 | 44 | 47 | 48 |
.528- .536 | 45 | 48 | 49 |
.537- .544 | 46 | 49 | 50 |
.545- .552 | 47 | 50 | 51 |
.553- .560 | 48 | 51 | 52 |
.561- .568 | 49 | 52 | 53 |
.569- .576 | 50 | 53 | 54 |
.577- .584 | 51 | 54 | 55 |
.585- .592 | 52 | 55 | 56 |
.593- .600 | 53 | 56 | 57 |
TABLE H-28
Part | Location | Extent of classified area 1 | Equipment shall be suitable for Class 1, Group D 2 |
A | Storage containers other than DOT cylinders | Within 15 feet in all directions from connections, except connections otherwise covered in Table H-28 | Division 2. |
B | Tank vehicle and tank car loading and unloading 3 | Within 5 feet in all directions from connections regularly made or disconnected for product transfer | Division 1. |
Beyond 5 feet but within 15 feet in all directions from a point where connections are regularly made or disconnected and within the cylindrical volume between the horizontal equator of the sphere and grade. (See Figure H-1) | Division 2. | ||
C | Gage vent openings other than those on DOT cylinders | Within 5 feet in all directions from point of discharge Beyond 5 feet but within 15 feet in all directions from point of discharge | Division 1. |
Division 2. | |||
D | Relief valve discharge other than those on DOT cylinders | Within direct path of discharge | Division 1. |
Within 5 feet in all directions from point of discharge | Division 1. | ||
Beyond 5 feet but within 15 feet in all directions from point of discharge except within the direct path of discharge | Division 2. | ||
E | Pumps, compressors, gas-air mixers and vaporizers other than direct fired | ||
Indoors without ventilation | Entire room and any adjacent room not separated by a gastight partition | Division 1. | |
Within 15 feet of the exterior side of any exterior wall or roof that is not vaportight or within 15 feet of any exterior opening | Division 2. | ||
Indoors with adequate ventilation 4 | Entire room and any adjacent room not separated by a gastight partition | Division 2. | |
Outdoors in open air at or abovegrade | Within 15 feet in all directions from this equipment and within the cylindrical volume between the horizontal equator of the sphere and grade. See Figure H-1 | Division 2. | |
F | Service Station Dispensing Units | Entire space within dispenser enclosure, and 18 inches horizontally from enclosure exterior up to an elevation 4 ft. above dispenser base. Entire pit or open space beneath dispenser | Division 1. |
Up to 18 inches abovegrade within 20 ft. horizontally from any edge of enclosure | Division 2. | ||
Note: For pits within this area, see part F of this table. | |||
G | Pits or trenches containing or located beneath LP-Gas valves, pumps, compressors, regulators, and similar equipment | ||
Without mechanical ventilation | Entire pit or trench | Division 1. | |
Entire room and any adjacent room not separated by a gastight partition | Division 1. | ||
Within 15 feet in all directions from pit or trench when located outdoors | Division 2. | ||
With adequate mechanical ventilation | Entire pit or trench | Division 2. | |
Entire room and any adjacent room not separated by a gastight partition | Division 2. | ||
Within 15 feet in all directions from pit or trench when located outdoors | Division 2. | ||
H | Special buildings or rooms for storage of portable containers | Entire room | Division 2. |
Pipelines and connections containing operational bleeds, drips, vents or drains | Within 5 ft. in all directions from point of discharge Beyond 5 ft. from point of discharge, same as part E of this table | Division 1. | |
J | Container filling: | ||
Indoors without ventilation | Entire room | Division 1. | |
Indoors with adequate ventilation 4 | Within 5 feet in all directions from connections regularly made or disconnected for product transfer | Division 1. | |
Beyond 5 feet and entire room | Division 2. | ||
Outdoors in open air | Within 5 feet in all directions from connections regularly made or disconnected for product transfer | Division 1. | |
Beyond 5 feet but within 15 feet in all directions from a point where connections are regularly made or disconnected and within the cylindrical volume between the horizontal equator of the sphere and grade. (See Figure H-1) | Division 2. |
1 The classified area shall not extend beyond an unpierced wall, roof, or solid vaportight partition.
2 See subpart S of this part.
3 When classifying extent of hazardous area, consideration shall be given to possible variations in the spotting of tank cars and tank vehicles at the unloading points and the effect these variations of actual spotting point may have on the point of connection.
4 Ventilation, either natural or mechanical, is considered adequate when the concentration of the gas in a gas-air mixture does not exceed 25 percent of the lower flammable limit under normal operating conditions.
Figure H-1
[(Water capacity (gals.) of container**filling density**)÷(Specific gravity of LP-Gas**volume correction factor * 100)]=Maximum volume of LP-Gas
*Measured at 60 °F.
**From subparagraph (12) of this paragraph "Filling Densities."
For aboveground containers the liquid temperature is assumed to be 40 °F. and for underground containers the liquid temperature is assumed to be 50 °F. To correct the liquid volumes at these temperatures to 60 °F. the following factors shall be used.
TABLE H-29-VOLUME CORRECTION FACTORS
Specific gravity | Aboveground | Underground |
0.500 | 1.033 | 1.017 |
.510 | 1.031 | 1.016 |
.520 | 1.029 | 1.015 |
.530 | 1.028 | 1.014 |
.540 | 1.026 | 1.013 |
.550 | 1.025 | 1.013 |
.560 | 1.024 | 1.012 |
.570 | 1.023 | 1.011 |
.580 | 1.021 | 1.011 |
.590 | 1.020 | 1.010 |
Example: Assume a 100-gallon total water capacity tank for aboveground storage of propane having a specific gravity of 0.510 of 60 °F.
[(100 (gals.)*42 (filling density from subparagraph (12) of this paragraph))÷(0.510*1.031 (correction factor from Table H-29)*100)]=(4200÷52.6)
(4200÷52.6)=79.8 gallons propane, the maximum amount permitted to be placed in a 100-gallon total water capacity aboveground container equipped with a fixed dip tube.
[(Maximum volume of LP-Gas (from formula in subdivision ( b ) of this subdivision)*100)÷Total water content of container in gallons]=Maximum percent of LP-Gas
Aboveground, pounds per gallon | Underground, pounds per gallon | |
Propane | 4.37 | 4.31 |
N Butane | 4.97 | 4.92 |
Except as provided in paragraph (b)(10)(xiii) of this section, the discharge from safety relief devices shall be located not less than 3 feet horizontally away from any building opening which is below the level of such discharge and shall not terminate beneath any building unless such space is well ventilated to the outside and is not enclosed on more than two sides.
The provisions of this paragraph ( h ) do not apply to tar kettle burners, torches, melting pots, nor do they apply to portable heaters under 7,500 B.t.u.h. input when used with containers having a maximum water capacity of 21/2 pounds. Container valves, connectors, regulators, manifolds, piping, and tubing shall not be used as structural supports for heaters.
Note: This provision is not to be construed as requiring an automatic changeover device.
TABLE H-30
Regulator delivery pressure | Relief valve start-to-discharge pressure setting (percent of regulator delivery pressure) | |
Minimum | Maximum | |
1 p.s.i.g. or less | 200 | 300 |
Above 1 p.s.i.g. but not over 3 p.s.i.g | 140 | 200 |
Above 3 p.s.i.g | 125 | 200 |
TABLE H-31
Container type | For gases with vapor press. Not to exceed lb. per sq. in. gage at 100 °F. (37.8 °C.) | Minimum design pressure of container, lb. per sq. in. gage | |
1949 and earlier editions of ASME Code (Par. U-68, U-69) | 1949 edition of ASME Code (Par. U-200, U-201); 1950, 1952, 1956, 1959, 1962, 1965, and 1968 (Division 1) editions of ASME Code; All editions of API-ASME Code 3 | ||
1 80 | 1 80 | 1 80 | 1 100 |
100 | 100 | 100 | 125 |
125 | 125 | 125 | 156 |
150 | 150 | 150 | 187 |
175 | 175 | 175 | 219 |
2 200 | 215 | 200 | 250 |
1 New storage containers of the 80 type have not been authorized since Dec. 31, 1947.
2 Container type may be increased by increments of 25. The minimum design pressure of containers shall be 100% of the container type designation when constructed under 1949 or earlier editions of the ASME Code (Par. U-68 and U-69). The minimum design pressure of containers shall be 125% of the container type designation when constructed under: (1) the 1949 ASME Code (Par. U-200 and U-201), (2) 1950, 1952, 1956, 1959, 1962, 1965, and 1968 (Division 1) editions of the ASME Code, and (3) all editions of the API-ASME Code.
3 Construction of containers under the API-ASME Code is not authorized after July 1, 1961.
Where there is a probability of the manhole or housing becoming flooded, the discharge from regulator vent lines shall be above the highest probable water level. All manholes or housings shall be provided with ventilated louvers or their equivalent, the area of such openings equaling or exceeding the combined discharge areas of the safety relief valves and other vent lines which discharge their content into the manhole housing.
It will not be necessary to cover the portion of the container to which manhole and other connections are affixed; however, where necessary, protection shall be provided against vehicular damage. When necessary to prevent floating, containers shall be securely anchored or weighted.
TABLE H-32
Container type | For gases with vapor press. Not to exceed lb. per sq. in. gage at 100 °F. (37.8 °C.) | Minimum design pressure of container, lb. per sq. in. gage | |
1949 and earlier editions of ASME Code (Par. U-68, U-69) | 1949 edition of ASME Code (Par. U-200, U-201); 1950, 1952, 1956, 1959, 1962, 1965, and 1968 (Division 1) editions of ASME Code; All editions of API-ASME Code 2 | ||
1 200 | 215Z | 200 | 250 |
1 Container type may be increased by increments of 25. The minimum design pressure of containers shall be 100% of the container type designation when constructed under 1949 or earlier editions of the ASME Code (Par. U-68 and U-69). The minimum design pressure of containers shall be 125% of the container type designation when constructed under:
2 Construction of containers under the API-ASME Code is not authorized after July 1, 1961.
TABLE H-33
Quantity of LP-Gas Stored | Distance |
500 pounds or less | 0 |
501 to 2,500 pounds | 1 0 |
2,501 to 6,000 pounds | 10 feet |
6,001 to 10,000 pounds | 20 feet |
Over 10,000 pounds | 25 feet |
1 Container or containers shall be at least 10 feet from any building on adjoining property, any sidewalk, or any of the exposures described in § 1910.110 (c) or (d) of this paragraph.
TABLE H-34
Container type | For gases with vapor press. Not to exceed lb. per sq. in. gage at 100 °F. (37.8 °C.) | Minimum design pressure of container, lb. per sq. in. gage | |
1949 and earlier editions of ASME Code (Par. U-68, U-69) | 1949 edition of ASME Code (Par. U-200, U-201); 1950, 1952, 1956, 1959, 1962, 1965, and 1968 (Division 1) editions of ASME Code; All editions of API-ASME Code 2 | ||
1 200 | 215 | 200 | 250 |
1 Container type may be increased by increments of 25. The minimum design pressure of containers shall be 100 percent of the container type designation when constructed under 1949 or earlier editions of the ASME Code (Par. U-68 and U-69). The minimum design pressure of containers shall be 125 percent of the container type designation when constructed under: (1) The 1949 ASME Code (Paragraphs U-200 and U-201), (2) 1950, 1952, 1956, 1959, 1962, 1965, and 1968 (Division 1) editions of the ASME Code, and (3) all editions of the API-ASME Code.
2 Construction of containers under the API-ASME Code is not authorized after July 1, 1961.
In lieu of an excess flow valve, filling connections may be fitted with a quick-closing internal valve, which shall remain closed except during operating periods. The mechanism for such valves may be provided with a secondary control which will cause it to close automatically in case of fire. When a fusible plug is used its melting point shall not exceed 220 °F.
Water capacity per container (gallons) | Minimum distances | |
Aboveground and underground (feet) | Between aboveground containers (feet) | |
Up to 2,000 | 25 | 3 |
Over 2,000 | 50 | 5 |
Note: The above distances may be reduced to not less than 10 feet for service station buildings of other than wood frame construction.
29 C.F.R. §1910.110