Section 296-36-120. Compression and decompression of workmen—Decompression tables.  


Latest version.
  • (1) Explanation.
    (a) The decompression tables are computed for working chamber pressures from 14 to 50 pounds per square inch gage inclusive by 2 pound increments and for exposure times for each pressure extending from 1/2 to over 8 hours inclusive. Decompressions will be conducted by two or more stages with a maximum of 4 stages, the latter for a working chamber pressure of 40 pounds per square inch gage or over.
    (b) Stage 1, consists of a reduction in ambient pressure ranging from 10 to a maximum of 16 pounds per square inch but in no instance will the pressure be reduced below 4 pounds at the end of stage 1. This reduction in pressure in stage 1 will always take place at a rate of 5 pounds per minute.
    (c) Further reduction in pressure will take place during stage 2 and subsequent stages as required at a slower rate but in no event at a rate greater than one pound per minute.
    (d) Decompression table No. 1 indicates in the body of the table the total decompression time in minutes for various combinations of working chamber pressure and exposure time.
    (e) Decompression table No. 2 in several sheets indicates for the same various combinations of working chamber pressure and exposure time the following:
    (i) The number of stages required;
    (ii) The reduction in pressure and the terminal pressure for each required stage;
    (iii) The time in minutes through which the reduction in pressure is accomplished for each required stage;
    (iv) The pressure reduction rate in minutes per pound for each required stage;
    Important note: The pressure reduction in each stage is accomplished at a uniform rate. Do not interpolate between values shown on the tables. Use the next higher value of working chamber pressure or exposure time should the actual working chamber pressure or the actual exposure time, respectively, fall between those for which calculated values are shown in the body of the tables.
    (2) Examples.
    (3)
    DECOMPRESSION TABLE NO. 1
    (4)
    DECOMPRESSION TABLE NO. 2
    DO NOT INTERPOLATE, USE NEXT HIGHER VALUE FOR CONDITIONS NOT COMPUTED
    [Rules (Part IV E), filed 12/28/62; § 2, filed 3/23/60.]
Rules (Part IV E), filed 12/28/62; § 2, filed 3/23/60.