Appendix A - Appendix A to Subpart S of Part 1926—Decompression Tables

1. Explanation. The decompression tables are computed for working chamber pressures from 0 to 14 pounds, and from 14 to 50 pounds per square inch gauge inclusive by 2-pound increments and for exposure times for each pressure extending from one-half to over 8 hours inclusive. Decompressions will be conducted by two or more stages with a maximum of four stages, the latter for a working chamber pressure of 40 pounds per square inch gauge or over.

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 not greater than 5 pounds per minute.

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 1 pound per minute.

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.

Decompression Table No. 2 indicates for the same various combinations of working chamber pressure and exposure time the following:

a. The number of stages required;

b. The reduction in pressure and the terminal pressure for each required stage;

c. The time in minutes through which the reduction in pressure is accomplished for each required stage;

d. 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.

Examples Minutes Example No. 1: 4 hours working period at 20 pounds gauge. Decompression Table No. 1: 20 pounds for 4 hours, total decompression time43 Decompression Table No. 2: Stage 1: Reduce pressure from 20 pounds to 4 pounds at the uniform rate of 5 pounds per minute. Elapsed time stage 1: 16/53 Stage 2 (final stage): Reduce pressure at a uniform rate from 4 pounds to 0-pound gage over a period of 40 minutes. Rate—0.10 pound per minute or 10 minutes per pound. Stage 2 (final) elapsed time40 Total time43 Example No. 2: 5-hour working period at 24 pounds gage. Decompression Table No. 1: 24 pounds for 5 hours, total decompression time117 Decompression Table No. 2: Stage 1: Reduce pressure from 24 pounds to 8 pounds at the uniform rate of 5 pounds per minute. Elapsed time stage 1: 16/53 Stage 2: Reduce pressure at a uniform rate from 8 pounds to 4 pounds over a period of 4 minutes. Rate, 1 pound per minute elapsed time, stage 24 Transfer men to special decompression chamber maintaining the 4-pound pressure during the transfer operation. Stage 3 (final stage): In the special decompression chamber, reduce the pressure at a uniform rate from 4 pounds to 0-pound gage over a period of 110 minutes. Rate, 0.037 pound per minute or 27.5 minutes per pound. Stage 3 (final) elapsed time110 Total time117

Decompression Table No. 1—Total Decompression Time

Work pressure p.s.i.g. Working period hours 1/21 1 1/22 3 4 5 6 7 8 Over 8 9 to 1233333333333 1466666666161633 167777771733484862 18777811174863637387 20778151543637383103113 22991624386893103113128133 24111223275292117122127137151 261314293469104126141142142163 281523314198127143153153165183 3017283862105143165168178188204 3219354385126163178193203213226 3421395898151178195218223233248 36244463113170198223233243253273 38284973128178203223238253263278 40314984143183213233248258278288 423756102144189215245260263268293 444364118154199234254264269269293 464474139171214244269274289299318 485189144189229269299309319319505894164209249279309329

Decompression Table No. 2

[Do not interpolate, use next higher value for conditions not computed]

Working chamber pressure p.s.i.g. Working period hours Decompression data Stage No. Pressure reduc. p.s.i.g. Time in stage minutes Pressure reduc. rate Min/pound Total time decompress minutes From To 141/2114420.206 24041.006 1114420.206 24041.006 1 1/2114420.206 24041.006 2114420.206 24041.006 3114420.206 24041.006 4114020.206 24041.006 5114420.206 24041.006 6114420.2024041.006 7114420.20240143.5016 8114420.20240143.5016 Over 8114420.20240307.5032 161/2116430.2024041.007 1116430.207 24041.007 1 1/2116430.2024041.007 2116430.2024041.007 3116430.2024041.007 4114430.2024041.007 5114430.207 24043.5017 6114430.20240307.5033 7114430.202404511.2548 8114430.202404511.2548 Over 8114430.202406015.0063 181/2118430.2024041.007 1118430.2024041.007 1 1/2118430.2024041.007 2118430.2024051.258 3118430.2024082.0011 4118430.20240143.5017 5118430.202404511.2548 6118430.202406015.0063 7118430.202406015.0063 8118430.202407017.5073 Over 8118430.202408421.0087 201/2120430.2024041.007 1120430.2024041.007 1 1/2120430.2024051.258 2120430.20240123.0015 3120430.20240123.0015 4120430.202404010.0043 5120430.202406015.0063 6120430.202407017.5073 7120430.202408020.0083 8120430.2024010025.00103 Over 8120430.2024011027.50113 221/2122630.2026061.009 1122630.2026061.009 1 1/2122630.20260132.2016 2122630.20260213.5024 3122630.20260355.8538 4122630.202606510.8368 5122630.202609015.0093 6122630.2024010016.67103 7122630.2026011018.35113 8122630.2026012520.80128 Over 8122630.2026013021.70133 241/2124830.2028441.0034041.0011 1124830.2028441.0034051.2512 1 1/2124830.2028441.00340164.0023 2124830.2028441.00340205.0027 3124830.2028441.003404511.2552 4124830.2028441.003408521.2592 5124830.2028441.0034011027.50117 6124830.2028441.0034011528.80122 7124830.2028441.0034012030.00127 8124830.2028441.0034013032.50137 Over 8124830.2028482.0034014035.00151 261/21261030.20210461.0034041.0013 11261030.20210461.0034051.2514 1 1/21261030.20210461.00340205.0029 21261030.20210461.00340256.2534 31261030.20210461.003406015.0069 41261030.20210461.003409523.75104 51261030.20210481.3334011528.80126 61261030.20210481.3334013032.50141 71261032.20210491.5034013032.50142 81261030.20210491.5034013032.50142 Over 81261030.202104305.003403032.50163 281/21281230.20212481.0034041.0015 11281230.20212481.00340123.0023 1 1/21281230.20212481.00340205.0031 21281230.20212481.00340307.5041 31281230.202124101.253408521.2098 41281230.202124141.7534011027.50127 51281230.202124202.5034012030.00143 61281230.202124202.5034013032.50153 71281230.202124202.5034012032.50153 81281230.202124324.0034013032.50165 Over 81281230.202124506.2534013032.50183 301/21301430.202144101.0034041.0017 11301430.202144101.00340153.7528 1 1/21301430.202144101.00340256.2538 21301430.202144141.403404511.2562 31301430.202144171.703408521.20105 41301430.202144303.0034011027.50143 51301430.202144353.5034013032.50165 61301430.202144353.5034013032.50168 71301430.202144454.5034013032.50178 81301430.202144555.5034013032.50188 Over 81301430.202144717.1034013032.50204 321/21321630.202164121.0034041.0019 11321630.202164121.00340205.0035 1 1/21321630.202164151.25340256.2543 21321630.202164221.833406015.0085 31321630.202164282.333409523.75126 41321630.202164403.3334012030.00163 51321630.202164453.7534013032.50178 61321630.202164605.0034013032.50193 71321630.202164705.8334013032.50203 81321630.202164806.6734013032.50213 Over 81321630.202164937.7534013032.50226 341/21341830.202184141.0034041.0021 11341830.202184141.00340225.5039 1 1/21341830.202184251.80340307.5058 21341830.202184352.503406015.0098 31341830.202184433.1034010526.25151 41341830.202184553.9334012030.00178 51341830.202184624.4334013032.50195 61341830.202184856.0734013032.50218 71341830.202184906.4334013032.50223 81341830.2021841007.1534013032.50233 Over 81341830.2021841158.2334013032.50248 361/21362030.202204161.0034051.2524 11362030.202204161.00340256.2544 1 1/21362030.202204301.88340307.5063 21362030.202204402.503407017.50113 31362030.202204523.2534011528.75170 41362030.202204654.0634013032.50198 51362030.202204905.6334013032.50223 61362030.2022041006.2534013032.50233 71362030.2022041106.8834013032.50243 81362030.2022041207.5034013032.50253 Over 81362030.2022041408.7534013032.50273 381/21382230.202226161.0036091.5028 11382230.202226161.00360305.0049 1 1/21382230.202226201.25360508.3473 21382230.202226301.883609515.83128 31382230.202226352.1936014023.35178 41382230.202226503.1236015025.00203 51382230.202226553.4436016527.50223 61382230.202226704.3836016527.50238 71382230.202226855.3236016527.50253 81382230.202226955.9336016527.50263 Over 81382230.2022261106.8836016527.50278 401/21402430.202248161.0038441.0044082.0031 11402430.202248161.0038451.25440256.2549 1 1/21402430.202248161.00384205.004404511.2584 22402430.201248251.56384205.004409523.75143 31402430.202248301.88384307.5044012030.00183 41402430.202248452.81384358.7544013032.50213 51402430.202248472.943845313.2544013032.50233 61402430.202248553.443846015.0044013032.50248 71402430.202248654.063846015.0044013032.50258 81402430.202248754.703846015.0044013032.50268 Over 81402430.202248955.933846015.0044013032.50288 421/21422630.2022610161.00310461.00440123.0037 11422630.2022610161.003104122.00440256.2556 1 1/21422630.2022610161.003104233.834406015.00102 21422630.2022610161.003104305.004409523.75144 31422630.2022610161.003104508.3444012030.00189 41422630.2022610171.0631046510.8344013032.50215 51422630.2022610271.6931048514.1844013032.50245 61422630.2022610271.69310410016.6744013032.50260 71422630.2022610301.88310410016.6744013032.50263 81422630.2022610352.19310410016.6744013032.50268 Over 81422630.2022610603.75310410016.6744013032.50293 441/21442830.2022812161.00312481.00440164.0043 11442830.2022812161.003124202.50440256.2564 1 1/21442830.2022812161.003124273.384407218.00118 21442830.2022812161.003124405.004409523.75154 31442830.2022812161.003124607.5044012030.00199 41442830.2022812161.0031248510.6244013032.50234 51442830.2022812161.00312410513.1344013032.50254 61442830.2022812161.00312411514.3844013032.50264 71442830.2022812161.00312412015.0044013032.50269 81442830.2022812161.00312412015.0044013032.50269 Over 81442830.2022812402.50312412015.0044013032.50293 461/21463030.2023014161.003144101.00440153.7544 11463030.2023014161.003144252.50440307.5074 1 1/21463030.2023014161.003144353.504408521.20139 21463030.2023014161.003144474.7044010526.25171 31463030.2023014161.003144656.5044013032.50214 41463030.2023014161.003144959.5044013032.50244 51463030.2023014161.00314412012.0044013032.50269 61463030.2023014161.00314412512.5044013032.50274 71463030.2023414161.00310414014.0044013032.50289 81463030.2023014161.00314415015.0044013032.50299 Over 81463030.2023014251.56314416016.0044013032.50318 481/21483230.2023216161.003164121.00440205.0051 11483230.2023216161.003164352.92440358.7589 1 1/21483230.2023216161.003164453.754408020.00144 21483230.2023216161.003164605.0044011027.50189 31483230.2023216161.003164907.5044012030.00229 41483230.2023216161.00316412010.0044013032.50269 51483230.2023216161.00316414011.6744013032.50209 61483230.2023216161.00316416013.3344013032.50309 71483230.2023216161.00316417014.1744013032.5081483230.2023216161.00316417014.1744013032.50501/21503430.2023418161.003184141.00440256.2558 11503430.2023418161.003184402.86440358.7594 1 1/21503430.2023418161.003184553.934409022.50164 21503430.2023418161.003184705.0044012030.00209 31503430.2023418161.0031841007.1544013032.50249 41503430.2023418161.0031841308.5844013032.50279 51503430.2023418161.00318416011.42

Decompression Table No. 2—Continued

[Do not interpolate, use next higher value for conditions not computed]

Working chamber pressure p.s.i.g. Working period hours Decompression data Stage No. Pressure reduc. p.s.i.g. Time in stage minutes Pressure reduc. rate Min/pound Total time decompress minutes From To 44013032.50309 61503430.2023418161.00318418012.8544013032.50329
[44 FR 8577, Feb. 9, 1979; 44 FR 20940, Apr. 6, 1979, as amended at 58 FR 35311, June 30, 1993]