Administrative Rules of Montana › Department 4 - AGRICULTURE › Chapter 4.12 - AGRICULTURAL SCIENCES DIVISION › Subchapter 4.12.7 - Anhydrous Ammonia Rules › Rule 4.12.743 - TABLES

Current through Register Vol. 13, July 5, 2024
(1) Table A - Rate of Discharge.
TABLE A - RATE OF DISCHARGE
Minimum required rate of discharge in cubic feet per minute
				  (CFM) of air for safety relief valves. Discharge measured at 60 degrees F and
				  atmospheric pressure (14.7 pounds per square inch).
Surface Area Sq. Ft.
CFM
Surface Area Sq. Ft.
CFM
Surface Area Sq. Ft
CFM
20
258
185
1,600
900
5,850
25
310
190
1,640
950
6,120
30
360
195
1,670
1,000
6,380
35
408
200
1,710
1,050
6,640
40
455
210
1,780
1,100
6,900
45
501
220
1,850
1,150
7,160
50
547
230
1,920
1,200
7,410
55
591
240
1,980
1,250
7,660
60
635
250
2,050
1,300
7,910
65
678
260
2,120
1,350
8,160
70
720
270
2,180
1,400
8,410
75
762
280
2,250
1,450
8,650
80
804
290
2,320
1,500
8,900
85
845
300
2,380
1,550
9,140
90
885
310
2,450
1,600
9,380
95
925
320
2,510
1,650
9,620
100
965
330
2,570
1,700
9,860
105
1,010
340
2,640
1,750
10,090
110
1,050
350
2,700
1,800
10,330
115
1,090
360
2,760
1,850
10,560
120
1,120
370
2,830
1,900
10,800
125
1,160
380
2,890
1,950
11,030
130
1,200
390
2,950
2,000
11,260
135
1,240
400
3,010
2,050
11,490
140
1,280
450
3,320
2,100
11,720
145
1,310
500
3,620
2,150
11,950
150
1,350
550
3,910
2,200
12,180
155
1,390
600
4,200
2,250
12,400
160
1,420
650
4,480
2,300
12,630
165
1,460
700
4,760
2,350
12,850
170
1,500
750
5,040
2,400
13,080
175
1,530
800
5,300
2,450
13,300
180
1,570
850
5,590
2,500
13,520
Surface area = Total outside surface area of container in
				  square feet. When the surface area is not stamped on the name plate or when the
				  marking is not legible, the area can be calculated by using one of the
				  following formulas:
(a)
Cylindrical container with hemispherical heads area =
							 (overall length in feet times outside diameter in feet times
							 3.1416).
(b)
Cylindrical container with semi-ellipsoidal heads.
							 Area = (overall length in feet plus 0.3 outside diameter in feet) times
							 diameter in feet times 3.1416.
(c)
Spherical Container. Area = Outside diameter
							 in
Flow Rate SCFM Air = Cubic feet per minute of air required
				  at standard conditions, 60 degrees F and atmospheric pressure (14.7
				  psia).
The rate of discharge may be interpolated for intermediate
				  values of surface area. For container with total outside surface area greater
				  than 2,000 sq. ft., the required flow rate can be calculated using the formula,
				  Flow Rate SCFM Air = 22.11A degrees .82, where A = Outside surface area of the
				  container in square feet.
(2) Table B - Guide for Selection of
				Materials for Refrigerated Ammonia Storage Tanks.
TABLE B - GUIDE FOR SELECTION OF MATERIALS
FOR REFRIGERATED AMMONIA STORAGE TANKS
(a)
Materials for shell and bottom for tanks of all
							 design pressures shall have ductility at low temperatures equal to or superior
							 to those listed in Table C.
(b)
When austenitic steels or non-ferrous materials are
							 used, the code shall be used as a guide for temperature
							 requirements.
(c)
Materials for nozzles, attached flanges, structural
							 members which are in tension, and other such critical elements shall be
							 selected for the design temperature. This selection shall be based on impact
							 test requirements, or on probabilities such as used for the plate materials
							 listed in Table C.
(3)
				Table C - Minimum Material Requirements for Shells and Bottoms of Refrigerated
				Storage Tanks for Various Temperatures and Thicknesses.
TABLE C - MINIMUM MATERIAL REQUIREMENTS FOR SHELLS AND
				  BOTTOMS OF REFRIGERATED STORAGE TANKS FOR VARIOUS TEMPERATURES AND THICKNESSES
Design Temperature
Thickness
Material Spec.
Qualifications to be Added to the Basic
								Specification
65 F to 25 F, Incl. (See Note 1)
Up to 1/2", Incl.
Any approved steel with specified min.T.S. not
								exceeding 60,000 psi
None
Over 1/2" to 1", Incl.
A-131B (or C)
None
Case 1256
None
A-201 A & B
FGP (Fine Grain Practice)
Over 1" to 1 3/8", Incl.
A-131C, Case 1256
None
A-201 A&B
None
FGP
Over 1 3/8"
A-131C
Normalized
Case 1256
Normalized
A-201 A & B
FGP, Normalized
Below 25 F to 5 F, Incl. (See Note 2)
Up to 1/2", Incl.
Case 1256
None
A-201 A & B
None
Over 1/2" to 1 3/8", Incl.
A-131B (to 1" max)
FGP
A-131C
FGP
Case 1256
FGP
A-201 A & B (to 1" max)
FGP, High Mang.*
A-201 A & B (over 1")
FGP, High Mang., Normalized
Over 1 3/8"
A-131C
Normalized
Case 1256
Normalized
A-201 A & B
FGP, High Mang., Normalized
Below -5F to -30F (See note 3)
Up to 1/2" Incl.
Case 1256
FGP
A-201 A & B
FGP, High Mang.
Over 1/2" to 1 3/8" Incl.
A-131B (to 1" max)
FGP, Normalized
A-131C
Normalized
Case 1256
FGP, Normalized
A-201 A & B
FGP, High Mang., Normalized
Over 1 3/8"
A-300 Class 1
A-201 A & B Only
*Manganese content of 0.70% to 1.0% is preferred in lieu of
				  usual content of 0.80% maximum.
Note 1: The design temperature shall be taken as the lower of
				  the following:
(a) The minimum
				temperature to which the tank contents will be refrigerated.
(b) The minimum estimated tank shell
				temperature due to atmospheric temperatures, considering effectiveness of the
				insulation in keeping shell temperatures above expected minimum atmospheric
				temperature (if expected to be below the refrigerated temperature) .
Note 2: For the thickness, temperature category approved
				  steels include all of those listed in the API 12-C and API 620. Materials for
				  vessels must comply with the requirements of the code and any additional
				  requirements of the code and any additional requirements of this table. A-131
				  steel is not approved by ASME and some code cases have not been approved by
				  local jurisdictions. All specific materials listed in table are satisfactory
				  for all designs based on API 12-C or API 620.
Note 3: For vessels constructed under the code with a design
				  temperature below -20F., the impact requirements shall comply with Table
				  B.