(a)   Certificate of Approval. A Certificate of Approval shall be obtained by the manufacturer from the Fire Chief and Commissioner for each type of liquefier or converter to be used for the conversion of solid carbon dioxide to liquid carbon dioxide as in full compliance with these rules. A Certificate of Approval shall also be obtained from the Fire Chief and Commissioner for each system used to convert solid carbon dioxide to liquid carbon dioxide for filling portable cylinders or other containers as in full compliance with these rules.
   (b)   Certificate of Fitness. A Certificate of Fitness shall be obtained from the Fire Chief and Commissioner for each operator of a liquefier system used to convert solid carbon dioxide to liquid carbon dioxide for filling portable cylinders or other containers.
   (c)   Inspection test report. A disinterested inspection service, approved by the Fire Chief and Commissioner, shall inspect all material and workmanship of all liquefiers at the place of manufacture and shall verify compliance with these rules, witness all tests and shall furnish the Fire Chief and Commissioner with a test report as follows:
      (1)   Test reports for liquefiers, other than redesigned portable cylinders, shall show all information called for in paragraph 23, I. C. C. Specification 3A, except as follows:
         (i)   "Marks stamped into shoulder of cylinder." This shall be as per §26-01(k) "Marking" hereinafter specified. Actual markings shall be shown on test report.
         (ii)   "Record of hydrostatic tests." This shall be as per §26-01(i) "Testing" hereinafter specified.
         (iii)   Statement shall be furnished that liquefier covered in said test report comply with these rules, and Certificate of Approval Number for the type of liquefier covered in said test report.
      (2)   Test report for converted portable cylinders for liquefier use shall show for each converted cylinder the following:
         (i)   Liquefier Serial Number.
         (ii)   Original number of cylinder used for conversion.
         (iii)   Original ownership initials of cylinders used for conversion.
         (iv)   Original I. C. C. marking of cylinder used for conversion.
         (v)   Original manufacturing test date of cylinder used for conversion, and name of original manufacturer.
         (vi)   Test pressure applied to cylinder before conversion.
         (vii)   Total expansion obtained on cylinder before conversion.
         (viii)   Permanent expansion obtained on cylinder before conversion.
         (ix)   Percent expansion obtained on cylinder before conversion.
         (x)   Elastic expansion obtained on cylinder before conversion.
         (xi)   Outside diameter and length of cylinder before conversion.
         (xii)   A statement that the above cylinders before conversion into liquefiers were tested in a water jacket in accordance with these rules and I. C. C. Regulations and the results appear above.
         (xiii)   A statement that the top thickness, opening for cover plate and distance across the corner where the side wall meets the bottom and at 45° to the side wall, was measured and the dimensions were found to conform with §26-01(f)(6), (7), (8) and (9).
         (xiv)   A statement that after assembly each liquefier was given an open hydrostatic test to 3,000 lbs. and this pressure was held for at least two minutes without showing a pressure recession of more than 75 lbs.
         (xv)   The liquefier was marked as follows: (See §26-01(k) "Marking" for requirements).
         (xvi)   A statement that these liquefiers conform to these rules, and that the type of liquefier had been approved under New York City Fire Department Certificate of Approval Number...
   (d)   Construction other than screw thread type. New liquefiers designed for the purpose of converting solid CO2 to liquid CO2 shall be constructed of seamless drawn steel in accordance with Specifications of I. C. C. governing cylinders for CO2. Closure devices other than screw thread type shall conform with the following:
      (1)   The minimum wall thickness for a test pressure of 3,000 lbs. per sq. in. shall be in accordance with the following formula:
         t = OD × P × .43
            S
 
 
Where OD
=
Outside diameter of container.
t
=
Wall thickness.
P
=
3,000 lbs. PSI.
S
=
Minimum yield point of hard steel (not to be figured in excess of 50,000 lbs.).
 
      (2)   The "top" is defined as that portion of the liquefier in which the closure device is installed and where the ice is introduced.
      (3)   The minimum thickness of the top before machining shall be at least 3 1/2 times the wall thickness.
      (4)   The minimum thickness of the top after machining shall be at least 3 times the wall thickness.
      (5)   The minimum distance from edge of the hole cut or chaped for the closure device to the outside of wall shall be 4 1/2 times the wall thickness.
      (6)   The maximum width of the machined seat shall not be more than 1 1/2 times the wall thickness.
      (7)   The outside radius connecting the top of the liquefier to its side wall shall not be more than 1 1/2 times the wall thickness.
      (8)   The inside radius connecting the side wall to the top before machining, shall not be less than 2 1/2 times the wall thickness.  In lieu of the requirements as set forth in paragraphs (3) to (8) inclusive above: The top portion of the liquefier including closure plate shall be designed with a factor of safety of not less than two at a test pressure of 3,000 lbs. per sq. inch. The design shall be proven by a test to destruction for each type of liquefier before a certificate of approval shall have been issued.
      (9)   A large fillet shall be provided in the corner of the machined seat where it meets the inside radius.
   (e)   Construction screw thread type. New liquefiers designed for the purpose of converting solid CO2 to liquid CO2 shall be constructed of seamless drawn steel in accordance with specifications of I. C. C. governing cylinders for CO2. Closure device of the screw thread type shall conform with the following:
      (1)   The minimum wall thickness for a test pressure of 3,000 lbs. per sq. in. shall be in accordance with the following formula:
         t = OD × P × .43
            S
 
Where OD
=
Outside diameter of container.
t
=
Wall thickness.
P
=
3,000 lbs. PSI.
S
=
Minimum yield point of hard steel (not to be figured in excess of 50,000 lbs.).
      (2)   The thread of the device shall be designed with a factor of safety of not less than 4 at a test pressure of 3,000 lbs. per sq. in. and the wall thickness after cutting thread shall not be less than that specified in §26-01(e)(1).
   (f)   Conversion of portable cylinders for liquefier use. Seamless portable cylinders made to I. C. C. Specification 3 or 3A for oxygen or carbon dioxide and originally designed and used for the transportation of compressed or liquefied gases shall be acceptable for alteration or conversion into carbon dioxide liquefiers only under the following conditions:
      (1)   Cylinders which have been in a fire shall not be used for conversion into liquefiers until they have been properly heat treated and retested as specified in paragraph 423, of the I. C. C. Regulations.
      (2)   Cylinders which show surface dents, or which fail to give a clear ring on being struck with a hammer, shall not be used for conversion into liquefiers.
      (3)   Before conversion into liquefiers, each cylinder shall be submitted to a hydrostatic test of 3,000 lbs. pressure in a water jacket under the conditions specified in paragraph 424 of the I. C. C. Regulations and the total and permanent expansion shall be recorded. A cylinder shall be condemned when it leaks or when the permanent expansion exceeds 10 percent of the total expansion.
      (4)   If in the hydrostatic test in the water jacket the net elastic expansion (total expansion less permanent expansion) at 3,000 lbs. exceeds the allowable limit given in the following table for the type of cylinder involved, such cylinder shall not be used for conversion into a liquefier. If the cubic capacity of a cylinder to be tested varies from the standard capacity given in the table for that type, then the allowable limit of elastic expansion will be varied in the same proportion.
TABLE I.
 
Type Cubic Capacity Elastic Expansion Allowable Limit
220 ft. oxygen
2,660 cu. in.
170 c.c.
200 ft. oxygen
2,660 cu. in.
170 c.c.
50 lbs. CO2
2,360 cu. in.
150 c.c.
      (5)   No cylinders designed and used for a portable container shall have the thickness of the side wall reduced by any cutting of threads in the process of conversion into a liquefier, except as specified in §26-01(e)(2).
      (6)   If the closure is formed by using a portion of the former bottom as a seat, this shall only be permissible if the dimensions of the liquefier conform to those shown in Tables II, III and IV.
TABLE II.
 
Type Minimum Bottom Thickness
220 ft. oxygen
66 in.
200 ft. oxygen
66 in.
50 lbs. CO2
66 in.
 
TABLE III.
 
Type Maximum Opening Permitted
220 ft. oxygen
61/8 in. × 71/8 in.
200 ft. oxygen
61/8 in. × 71/8 in.
50 lbs. CO2
53/4 in. × 63/4 in.
 
TABLE IV.
 
Type
Minimum Thickness across corner at Point where the outside of the side wall meets the inside radius of bottom and at 45° to side
220 ft. oxygen
5/8 in.
200 ft. oxygen
5/8 in.
50 lbs. CO2
5/8 in.
 
      (7)   The maximum width of the machined seat for the gasket of liquefier shall be 5/16 in., and the inside radius connecting this seat to the side wall of the cylinder shall not be less than 1/8 in.
      (8)   The minimum thickness of closure plate shall be 5 times the wall thickness of the cylinder. The closure plate shall be of a good grade of billet steel. Castings not permitted.
      (9)   Before conversion into a liquefier, the cylinder shall meet a new hydrostatic test at the pressure at which such cylinder was originally tested, provided, however, that no cylinder shall be converted unless for its original use it was tested to 3,000 lbs. pressure. Such new test shall be in a water jacket before conversion into a liquefier.
   (g)   Spuds. Spuds for chain connections or for reinforcing valve or pipe connections of not over 3/4 in. pipe size shall be welded before heat treatment at place of manufacture of the liquefier.
   (h)   Safety devices. Each liquefier shall be provided with two safety devices of frangible disc type attached to the liquefier at a point not lower than 6 inches from the top. The cross section area of the discharge channel, or channels (of the safety device, or devices) shall be at least .006 sq. in. for each 25 lbs. of liquefier water capacity and .00024 sq. in. additional for each additional pound of water capacity. Safety devices having two or more outlets shall be so constructed that these outlets will have a combined total area of not less than one and one-half times that prescribed for the safety discharge channel. The frangible disc of the safety devices shall be designed to release at a pressure of not more than 2,000 lbs. per sq. in.
   (i)   Testing. Each liquefier after assembly shall be tested hydrostatically by an approved independent testing agency for not less than two minutes to a pressure of 3,000 lbs. per sq. in. without showing a pressure recession of more than 75 lbs. per sq. in. The inspection service shall file a satisfactory record on test report stating that the liquefier passed the above required test.
   (j)   Quinquennial test. Liquefiers used for any purpose shall be retested at least every five years to a pressure of 3,000 lbs. per sq. in. in the same manner and under the same requirements as at the time and place of manufacture and the date of retest shall be stamped thereon.
   (k)   Marking. Each liquefier shall bear marking as follows:
      (1)   Name of owner.
      (2)   Serial number.
      (3)   Name or trade mark of manufacturer.
      (4)   Date of manufacture.
      (5)   Test pressure.
      (6)   Inspection service mark.
      (7)   Maximum filling charge based on filling to not more than 68 percent of the water content by weight.
   (l)   Filling. Each liquefier shall be placed and used in a vertical position with filling effected while liquefier is properly secured.
   (m)   Maximum charge. Liquefiers shall not be filled with solid carbon dioxide in excess of 150 lbs. not in excess of 68 percent by weight of the water capacity of the liquefier.
   (n)   Use of CO2 systems and liquefiers. (1) Carbon dioxide liquefier converting systems for filling portable cylinders shall not be used in any building occupied in whole or in part as a residence or as a multiple dwelling, or as place of public assembly, or in a building not used exclusively for manufacturing purposes.
      (2)   Except in buildings used exclusively for the manufacture of carbon dioxide or other compressed gases, not more than 8 liquefiers of a maximum combined capacity of 1,200 lbs. of carbon dioxide shall be headed in a battery and not more than one such battery shall be permitted in a building.
      (3)   Liquefiers may be manifolded only by the use of extra heavy steel or wrought iron pipe, or extra heavy seamless copper or brass tubing, of not larger than 3/4 in. I.P.S. Fittings shall be high pressure forged steel or extra heavy bronze hydraulic type.
      (4)   Each manifold shall be protected by a frangible disc safety device of the same size and type as those prescribed for the liquefier, and designed to release at a pressure of not more than 2,000 lbs. per sq. in. In addition, the liquid manifold shall be protected by a spring safety valve so set as to relieve the pressure at not more than 1,600 lbs. per sq. in.
      (5)   When carbon dioxide gas is conducted through pressure reducing valve between liquefier and point of use, the use of a heater will be permitted, but said heater shall be so arranged that heat may be applied indirectly. This heater shall consist of a coil immersed in water. The source of heat shall then be applied to the water but not directly to the coil.
   (o)   Test of piping. Each liquefier or battery of liquefiers to be used for the filling of portable cylinders or other containers with liquid carbon dioxide and all the piping connected thereto, shall be hydrostatically tested in the presence of the representatives of the Fire Chief and Commissioner before the solid carbon dioxide is first put into the system. A hydrostatic pressure of 2,400 lbs. per sq. in. shall be maintained for fifteen minutes, released for five minutes, and again applied for a period of fifteen minutes without any visible leak or reduction of pressure. This test shall be repeated at least every five years.
   (p)   Approval systems for filling portable cylinders. Each liquefier or battery of liquefiers used for filling portable cylinders or other containers, shall be permanently labeled or marked showing the Fire Department Certificate of Approval Number together with date of last test.
   (q)   Acceleration. Defrosting or acceleration of liquefication, shall be by use of water only, the water shall be of a temperature not above 85 degrees Fahrenheit.
   (r)   CO2 portable cylinders.
      (1)   Portable cylinders or other containers to be filled with liquid carbon dioxide shall be constructed and marked in accordance with the Specifications of the Interstate Commerce Commission for carbon dioxide cylinders and shall have been tested within intervals of not more than five years as evidenced by official marking. Cylinders not so constructed and marked shall not be filled with carbon dioxide.
      (2)   The maximum filling of liquid carbon dioxide, with one pound allowable variation in each cylinder, shall not be over 20 lbs. for standard cylinders 5 1/2 in. in diameter by 51 in. long, nor over 50 lbs. for standard cylinder 8 1/2 in. in diameter by 51 in. long and larger. No cylinder shall be filled with carbon dioxide to more than 68 percent of the water capacity, by weight, of the cylinder.
      (3)   The amount of liquid carbon dioxide charged into portable cylinders or other containers shall be determined by weight by use of a dial scale having a movable indicator, and this weight shall also be checked after disconnecting from the charging line.
   (s)   Existing installations. Liquefiers or converters to which these rules and regulations cannot be applied, may be maintained and operated, if approved by the Board of Standards and Appeals, under such conditions as are deemed necessary in the interest of public safety. These regulations apply to installations or alterations made prior to December 6, 1968, the effective date of Local Law 76 of 1968 (Building Code).
Resources