29 C.F.R. § 1926 app A to Subpart S of Part 1926

Current through September 30, 2024
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
1/2 1 11/2 2 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
485189144189229269299309319319
505894164209249279309329

Decompression Table No. 2

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

Working chamber pressure p.s.i.g.Working period hoursDecompression data
Stage No.Pressure reduc. p.s.i.g.Time in stage minutesPressure reduc. rate Min/poundTotal time decompress minutes
FromTo
141/2114420.206
24041.006
1114420.206
24041.006
11/2114420.206
24041.006
2114420.206
24041.006
3114420.206
24041.006
4114020.206
24041.006
5114420.206
24041.006
6114420.20
24041.006
7114420.20
240143.5016
8114420.20
240143.5016
Over 8114420.20
240307.5032
161/2116430.20
24041.007
1116430.207
24041.007
11/2116430.20
24041.007
2116430.20
24041.007
3116430.20
24041.007
4114430.20
24041.007
5114430.207
24043.5017
6114430.20
240307.5033
7114430.20
2404511.2548
8114430.20
2404511.2548
Over 8114430.20
2406015.0063
181/2118430.20
24041.007
1118430.20
24041.007
11/2118430.20
24041.007
2118430.20
24051.258
3118430.20
24082.0011
4118430.20
240143.5017
5118430.20
2404511.2548
6118430.20
2406015.0063
7118430.20
2406015.0063
8118430.20
2407017.5073
Over 8118430.20
2408421.0087
201/2120430.20
24041.007
1120430.20
24041.007
11/2120430.20
24051.258
2120430.20
240123.0015
3120430.20
240123.0015
4120430.20
2404010.0043
5120430.20
2406015.0063
6120430.20
2407017.5073
7120430.20
2408020.0083
8120430.20
24010025.00103
Over 8120430.20
24011027.50113
221/2122630.20
26061.009
1122630.20
26061.009
11/2122630.20
260132.2016
2122630.20
260213.5024
3122630.20
260355.8538
4122630.20
2606510.8368
5122630.20
2609015.0093
6122630.20
24010016.67103
7122630.20
26011018.35113
8122630.20
26012520.80128
Over 8122630.20
26013021.70133
241/2124830.20
28441.00
34041.0011
1124830.20
28441.00
34051.2512
11/2124830.20
28441.00
340164.0023
2124830.20
28441.00
340205.0027
3124830.20
28441.00
3404511.2552
4124830.20
28441.00
3408521.2592
5124830.20
28441.00
34011027.50117
6124830.20
28441.00
34011528.80122
7124830.20
28441.00
34012030.00127
8124830.20
28441.00
34013032.50137
Over 8124830.20
28482.00
34014035.00151
261/21261030.20
210461.00
34041.0013
11261030.20
210461.00
34051.2514
11/21261030.20
210461.00
340205.0029
21261030.20
210461.00
340256.2534
31261030.20
210461.00
3406015.0069
41261030.20
210461.00
3409523.75104
51261030.20
210481.33
34011528.80126
61261030.20
210481.33
34013032.50141
71261032.20
210491.50
34013032.50142
81261030.20
210491.50
34013032.50142
Over 81261030.20
2104305.00
3403032.50163
281/21281230.20
212481.00
34041.0015
11281230.20
212481.00
340123.0023
11/21281230.20
212481.00
340205.0031
21281230.20
212481.00
340307.5041
31281230.20
2124101.25
3408521.2098
41281230.20
2124141.75
34011027.50127
51281230.20
2124202.50
34012030.00143
61281230.20
2124202.50
34013032.50153
71281230.20
2124202.50
34012032.50153
81281230.20
2124324.00
34013032.50165
Over 81281230.20
2124506.25
34013032.50183
301/21301430.20
2144101.00
34041.0017
11301430.20
2144101.00
340153.7528
11/21301430.20
2144101.00
340256.2538
21301430.20
2144141.40
3404511.2562
31301430.20
2144171.70
3408521.20105
41301430.20
2144303.00
34011027.50143
51301430.20
2144353.50
34013032.50165
61301430.20
2144353.50
34013032.50168
71301430.20
2144454.50
34013032.50178
81301430.20
2144555.50
34013032.50188
Over 81301430.20
2144717.10
34013032.50204
321/21321630.20
2164121.00
34041.0019
11321630.20
2164121.00
340205.0035
11/21321630.20
2164151.25
340256.2543
21321630.20
2164221.83
3406015.0085
31321630.20
2164282.33
3409523.75126
41321630.20
2164403.33
34012030.00163
51321630.20
2164453.75
34013032.50178
61321630.20
2164605.00
34013032.50193
71321630.20
2164705.83
34013032.50203
81321630.20
2164806.67
34013032.50213
Over 81321630.20
2164937.75
34013032.50226
341/21341830.20
2184141.00
34041.0021
11341830.20
2184141.00
340225.5039
11/21341830.20
2184251.80
340307.5058
21341830.20
2184352.50
3406015.0098
31341830.20
2184433.10
34010526.25151
41341830.20
2184553.93
34012030.00178
51341830.20
2184624.43
34013032.50195
61341830.20
2184856.07
34013032.50218
71341830.20
2184906.43
34013032.50223
81341830.20
21841007.15
34013032.50233
Over 81341830.20
21841158.23
34013032.50248
361/21362030.20
2204161.00
34051.2524
11362030.20
2204161.00
340256.2544
11/21362030.20
2204301.88
340307.5063
21362030.20
2204402.50
3407017.50113
31362030.20
2204523.25
34011528.75170
41362030.20
2204654.06
34013032.50198
51362030.20
2204905.63
34013032.50223
61362030.20
22041006.25
34013032.50233
71362030.20
22041106.88
34013032.50243
81362030.20
22041207.50
34013032.50253
Over 81362030.20
22041408.75
34013032.50273
381/21382230.20
2226161.00
36091.5028
11382230.20
2226161.00
360305.0049
11/21382230.20
2226201.25
360508.3473
21382230.20
2226301.88
3609515.83128
31382230.20
2226352.19
36014023.35178
41382230.20
2226503.12
36015025.00203
51382230.20
2226553.44
36016527.50223
61382230.20
2226704.38
36016527.50238
71382230.20
2226855.32
36016527.50253
81382230.20
2226955.93
36016527.50263
Over 81382230.20
22261106.88
36016527.50278
401/21402430.20
2248161.00
38441.00
44082.0031
11402430.20
2248161.00
38451.25
440256.2549
11/21402430.20
2248161.00
384205.00
4404511.2584
22402430.20
1248251.56
384205.00
4409523.75143
31402430.20
2248301.88
384307.50
44012030.00183
41402430.20
2248452.81
384358.75
44013032.50213
51402430.20
2248472.94
3845313.25
44013032.50233
61402430.20
2248553.44
3846015.00
44013032.50248
71402430.20
2248654.06
3846015.00
44013032.50258
81402430.20
2248754.70
3846015.00
44013032.50268
Over 81402430.20
2248955.93
3846015.00
44013032.50288
421/21422630.20
22610161.00
310461.00
440123.0037
11422630.20
22610161.00
3104122.00
440256.2556
11/21422630.20
22610161.00
3104233.83
4406015.00102
21422630.20
22610161.00
3104305.00
4409523.75144
31422630.20
22610161.00
3104508.34
44012030.00189
41422630.20
22610171.06
31046510.83
44013032.50215
51422630.20
22610271.69
31048514.18
44013032.50245
61422630.20
22610271.69
310410016.67
44013032.50260
71422630.20
22610301.88
310410016.67
44013032.50263
81422630.20
22610352.19
310410016.67
44013032.50268
Over 81422630.20
22610603.75
310410016.67
44013032.50293
441/21442830.20
22812161.00
312481.00
440164.0043
11442830.20
22812161.00
3124202.50
440256.2564
11/21442830.20
22812161.00
3124273.38
4407218.00118
21442830.20
22812161.00
3124405.00
4409523.75154
31442830.20
22812161.00
3124607.50
44012030.00199
41442830.20
22812161.00
31248510.62
44013032.50234
51442830.20
22812161.00
312410513.13
44013032.50254
61442830.20
22812161.00
312411514.38
44013032.50264
71442830.20
22812161.00
312412015.00
44013032.50269
81442830.20
22812161.00
312412015.00
44013032.50269
Over 81442830.20
22812402.50
312412015.00
44013032.50293
461/21463030.20
23014161.00
3144101.00
440153.7544
11463030.20
23014161.00
3144252.50
440307.5074
11/21463030.20
23014161.00
3144353.50
4408521.20139
21463030.20
23014161.00
3144474.70
44010526.25171
31463030.20
23014161.00
3144656.50
44013032.50214
41463030.20
23014161.00
3144959.50
44013032.50244
51463030.20
23014161.00
314412012.00
44013032.50269
61463030.20
23014161.00
314412512.50
44013032.50274
71463030.20
23414161.00
310414014.00
44013032.50289
81463030.20
23014161.00
314415015.00
44013032.50299
Over 81463030.20
23014251.56
314416016.00
44013032.50318
481/21483230.20
23216161.00
3164121.00
440205.0051
11483230.20
23216161.00
3164352.92
440358.7589
11/21483230.20
23216161.00
3164453.75
4408020.00144
21483230.20
23216161.00
3164605.00
44011027.50189
31483230.20
23216161.00
3164907.50
44012030.00229
41483230.20
23216161.00
316412010.00
44013032.50269
51483230.20
23216161.00
316414011.67
44013032.50209
61483230.20
23216161.00
316416013.33
44013032.50309
71483230.20
23216161.00
316417014.17
44013032.50
81483230.20
23216161.00
316417014.17
44013032.50
501/21503430.20
23418161.00
3184141.00
440256.2558
11503430.20
23418161.00
3184402.86
440358.7594
11/21503430.20
23418161.00
3184553.93
4409022.50164
21503430.20
23418161.00
3184705.00
44012030.00209
31503430.20
23418161.00
31841007.15
44013032.50249
41503430.20
23418161.00
31841308.58
44013032.50279
51503430.20
23418161.00
318416011.42

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 hoursDecompression data
Stage No.Pressure reduc. p.s.i.g.Time in stage minutesPressure reduc. rate Min/poundTotal time decompress minutes
FromTo
44013032.50309
61503430.20
23418161.00
318418012.85
44013032.50329

29 C.F.R. 1926 app A to Subpart S of Part 1926

44 FR 8577, Feb. 9, 1979; 44 FR 20940, Apr. 6, 1979, as amended at 58 FR 35311, June 30, 1993