Pressure Equivalents

To Obtain
Multiply Number Of		Kg Per Square CentimeterPounds Per Square InchAtmosphereBarInches of MercuryKilopascalsInches of Water ColumnFeet of Water Column
Kg per square cm114,220,9678098 06728,9698 ,067394,0532,84
Pounds per square inch007 03110,06804006 8952,0366 ,89527,72,309
Atmosphere10 33214,6961101 32529,92101 325407,1433,93
Bar101 97214,50380,98692129,53100402,15633,513
Inches of Mercury003 4530,49120,033420 033 86413 ,386413,611,134
Kilopascals00 101 9720,1450380,00986960010,295314,021560,33513
Inches of Water0 002 5380,03610,002456000 2490,073490 24910,0833
Feet of Water03 0450,43320,029470 029 8390,881929 839121
1 ounce per square inch = 0.0625 pounds per square inch

Volume Equivalents

To Obtain
Multiply Number Of		Cubic Decimeters (Liters)Cubic InchesCubic FeetU.S. QuartU.S. GallonImperial GallonU.S. Barrel (Petroleum)
Cubic Decimeters (Liters)161,02340,035311,056680,2641780,2200830,00629
Cubic Inches0,0163915,787 * 10-41,017320,0043290,0036060,000103
Cubic Feet28 3171728129,92217,48055622 8880,1781
U.S. Quart094 63657,750,0334210,2502 0820,00595
U.S. Gallon378 5432310,13368410 8330,02381
Imperial Gallon454 374277,2740,160544,801281,2003210,02877
U.S. Barrel (Petroleum)15 89897025,61461684234 9731

Converting Volumes of Gas

CFH to CFH or CFM to CFM
Multiply Flow ofByTo Obtain Flow of
Air0,707Butane
1,290Natural Gas
0,808Propane
Butane1,414Air
1,826Natural Gas
1,140Propane
Natural Gas0,775Air
0,547Butane
0,625Propane
Propane1,237Air
0,874Butane
1,598Natural Gas

Length Equivalents

To Obtain
Multiply Number Of		MetersInchesFeetMillimetersMilesKilometers
Meters139,373,280810000,00062140 001
Inches00 25410,08332540,0000157800 000 254
Feet03 0481213 0480,000189400 003 048
Millimeters0 0010,039370,003280810,00000062140 000 001
Miles160 93563 3605 2801 609 3501160 935
Kilometers100039 ,3703280,831 000 0000,621371
1 meter = 100 cm = 1000 mm = 0,001 km = 1,000 ,000 micrometers

Length Equivalents - Fractional and Decimal Inches to Millimeters

InchesmmInchesmmInchesmmInchesmm
FractionsDecimalsFractionsDecimalsFractionsDecimalsFractionsDecimals
 0,003940,1 0,235,8421/20,5012,7 0,7719,558
 0,007870,215/640,2343755,9531 0,5112,954 0,7819,812
 0,010,254 0,236226,0 0,5118113,025/320,7812519,8438
 0,011810,3 0,246,09633/640,51562513 0969 0,7874020,0
1/640,0156250,39691/40,256,35 0,5213,208 0,7920,066
 0,015750,4 0,266,604 0,5313,46251/640,79687520,2406
 0,019690,517/640,2656256,746917/320,5312513,4938 0,8020,320
 0,020,508 0,276,858 0,5413,716 0,8120,574
 0,023620,6 0,275597,035/640,54687513,890613/640,812520,6375
 0,027560,7 0,287,112 0,5513,970 0,8220,828
 0,030,7629/320,281257,1438 0,5511814,0 0,8267721,0
1/320,031250,7938 0,297,366 0,5614,22453/640,82812521,0344
 0,03150,819/640,2968757,54069/160,562514,2875 0,8321,082
 0,135430,9 0,307,62 0,5714,478 0,8421,336
 0,039371,0 0,317,87437/640,57812514,684427/320,8437521,4312
 0,041,0165/160,31257,9375 0,5814,732 0,8521,590
3/640,0468751,1906 0,314968,0 0,5914,98655/640,85937521,8281
 0,051,27 0,328,128 0,590515,0 0,8621,844
 0,061,52421/640,3281258,334419/320,5937515,0812 0,8661422,0
1/160,06251,5875 0,338,382 0,6015,24 0,8722,098
 0,071,778 0,348,63639/640,60937515,47817/80,87522,225
5/640,0781251,984411/320,343758,7312 0,6115,494 0,8822,352
 0,078742,0 0,358,89 0,6215,748 0,8922,606
 0,082,032 0,354339,05/80,62515,87557/640,89062522,6219
 0,092,28623/640,3593759,1281 0,6299216,0 0,9022,860
3/320,093752,3812 0,369,144 0,6316,002 0,9055123,0
 0,12,54 0,379,398 0,6416,25629/320,9062523,0188
7/640,1093752,77813/80,3759,52541/640,64062516,2719 0,9123,114
 0,112,794 0,389,652 0,6516,510 0,9223,368
 0,118113,0 0,399,90621/320,6562516,668859/640,92187523,1456
 0,123,04825/640,3906259,9219 0,6616,764 0,9323,622
1/80,1253,175 0,3937010,0 0,6692917,015/160,937523,8125
 0,133,302 0,4010,16 0,6717,018 0,9423,876
 0,143,55613/320,4062510,318843/640,67187517,0656 0,9448824,0
9/640,1406253,5719 0,4110,414 0,6817,272 0,9524,130
 0,153,810 0,4210,66811/160,687517,462561/640,95312524,2094
5/320,156253,968827/640,42187510,7156 0,6917,526 0,9624,384
 0,157484,0 0,4310,922 0,7017,7831/320,9687524,6062
 0,164,064 0,4330711,045/640,70312517,8594 0,9724,638
 0,174,3187/160,437511,1125 0,7086618,0 0,9824,892
11/640,1718754,3656 0,4411,176 0,7118,034 0,9842525,0
 0,184,572 0,4511,43023/320,7187518,256263/640,98437525,0031
3/160,18754,762529/640,45312511,5094 0,7218,288 0,9925,146
 0,194,826 0,4611,684 0,7318,54211,0000025,4000
 0,196855,015/320,4687511,906247/640,73437518,6531   
 0,25,08 0,4711,938 0,7418,796   
13/640,2031255,1594 0,4724412,0 0,7480319,0   
 0,215,334 0,4812,1923/40,7519,050   
7/320,218755,556231/640,48437512,3031 0,7619,304   
 0,225,588 0,4912,44649/640,76562519,4469   
Note: Round off decimal points to provide no more than the desired degree of accuracy.

Diameter of Bolt Circles

Nominal Pipe Size, InchesASME CL125 (Cast Iron) ORCL1SO (Steel)(1)ASME CL250 (Cast Iron OR CL300 (Steel)(2)ASME CL600ASME CL900ASME CL1500ASME CL2500
13,123,503,504,004,004,25
1-1/43,503,883,884,384,385,12
1-1/23,884,504,504,884,885,75
24,755,005,006,506,506,75
2-1/25,505,885,887,507,507,75
36,006,626,627,508,009,00
47,507,888,509,259,5010,75
58,509,2510,5011,0011,5012,75
639,5010,6211,5012,5012,5014,50
811,7513,0013,7515,5015,5017,25
1014,2515,2517,0018,5019,0021,75
1217,0017,7519,2521,0022,5024,38
1418,7520,2520,7522,0025,00-
1621,2522,5023,7524,2527,75-
1822,7524,7525,7527,0030,50-
2025,0027,0028,5029,5032,75-
2429,5032,0033,0035,5039,00-
3036,0039,25----
3642,7546,00----
4249,5052,75----
4856,0060,75----
1. Sizes 1 through 12-inches also apply to ASME Class 150 bronze flanges.
2. Sizes 1 through 8-inches also apply to ASME Class 300 bronze flanges.

Equivalent Lengths of Pipe Fittings and Valves

Type of Fitting or ValveLengths in Feet of Standard Pipe
Nominal Pipe Size in Inches
1/23/411-1/41-1/222-1/23468101214
0.D.		16
0.D.		18
0.D.		20
0.D.		24
0.D.		30
0.D.
Standard tee with entry or discharge through side3,44,55,57,59,012141722334355657885105115135170
Standard elbow or run<1> of tee reduced 1121211,72,22,73,74,35,56,581216202631364247526480
Medium sweep elbow or run<1> of tee reduced 1/4(211,31,82,33,03,74,65,46,89,014182226303540435567
Long sweep elbow or run(1J of standard tee or butterfly valve11,31,72,32,73,54,25,3711141720232631344152
45’ elbow0,81,01,21,62,02,53,03,75,07,5101215172022243037
Close return bend3,75,16,28,510131519243749627586100110125150185
Globe valve, wide-open0,622274043456582120170240290340400440500550680850
Angle valve, wide-open8,2111418212833425685112145165190220250280340420
Swing check valve, wide-open4,05,26,69,011141619263952667892106120130145160
Gate valve, zwide-open, or slight bushing reduction0,40,50,60,80,91,21,31,72,33,54,55,76,78,09,011121417
1. Sizes 1 through 12-inches also apply to ASME Class 150 bronze flanges.
2. Sizes 1 through 8-inches also apply to ASME Class 300 bronze flanges.

American Pipe Flange Dimensions

ASME Class Flange Diameter-inches, Per ASME B16.1, B16.5, and B16.24
Nominal Pipe Size125 (Cast Iron)
or 150 (Steel)(1)		250 (Cast Iron)
or 300 (Steel)(2)		60090015002500
14,254,884,885,885,886,25
1-1/44,625,255,256,256,257,25
1-1/25,006,126,127,007,008,00
26,006,506,508,508,509,25
2-1/27,007,507,509,629,6210,50
37,508,258,259,5010,5012,00
49,0010,0010,7511,5012,2514,00
510,0011,0013,0013,7514,7516,50
611,0012,5014,0015,0015,5019,00
813,5015,0016,5018,5019,0021,75
1016,0017,5020,0021,5023,0026,50
1219,0020,5022,0024,0026,5030,00
1421,0023,0023,7525,2529,50-
1623,5025,5027,0027,7532,50-
1825,0028,0029,2531,0036,00-
2027,5030,5032,0033,7538,75-
2432,0036,0037,0041,0046,00-
3038,7543,00----
3646,0050,00----
4253,0057,00----
4859,5065,00----
1. Sizes 1 through 12-inch also apply to ASME Class 150 bronze flanges.
2. Sizes 1 through 8-inch also apply to ASME Class 300 bronze flanges.

American Pipe Flange Dimensions

ASME Class, Number of Stud Bolts and Hole Diameter in Inches, Per ASME B16.1, B16.5, and B16.24
Nominal Pipe Size125 (Cast Iron)
or 150 (Steel)(1)		250 (Cast Iron)
or 300 (Steel)(2)		60090015002500
 No.ØNo.ØNo.ØNo.ØNo.ØNo.Ø
140,5040,6240,6240,8840,8840,88
1-1/440,5040,6240,6240,8840,8841,00
1-1/240,5040,7540,7541,0041,0041,12
240,6280,6280,6280,8880,8881,00
2-1/240,6280,7580,7581,0081,0081,12
340,6280,7580,7580,8881,1281,25
480,6280,7580,7580,1281,2581,50
580,7580,7581,0081,2581,5081,75
680,75120,75121,00121,12121,3882,00
880,75120,88121,12121,38121,62122,00
10120,88161,00161,25161,38121,88122,50
12120,88161,12201,25201,38162,00122,75
14121,00201,12201,38201,50162,25--
16161,00201,25201,50201,62162,50--
18161,12241,25201,62201,88162,75--
20201,12241,25241,62202,00163,00--
24201,25241,50241,88202,50163,50--
30281,25281,75--------
36321,50322,00--------
42361,50362,00--------
48441,50402,00--------
1. Sizes 1 through 12-inch also apply to ASME Class 150 bronze flanges.
2. Sizes 1 through 8-inch also apply to ASME Class 300 bronze flanges.

Flange, Valve Size, and Pressure-Temperature Rating Designations

Sizes of ASME flanges are designated as NPS (for “nominal pipe size”). The nominal size is based on inches, but the units are not required in the designation. For example: NPS 2 is the size. Pressure ratings are designated by class. For example, CL150 is the rating. ASME designations replace ANSI designations.

Sizes of EN and ISO flanges are designated with DN (for “nominal diameter”). The nominal diameter is based on millimeters, but the units are not included in the designation. For example: DN 50 is the size. Pressure ratings are designated by PN (for “nominal pressure”). For example PN 40 is the pressure rating. EN and ISO designations replace DIN designations through PN 100.

ASME B 16.5 flanges will mate with EN 1759 flanges but not with EN 1092 flanges (formerly DIN flanges). ASME B16.5 flanges will mate with most ISO 7005 flanges.

Common size designations in wide use are shown in the table below.

A summary of flange terminology is shown in the table below, and equivalency of flanges is shown in the table on the following page.

Pipe Thread Standards

There are three pipe thread standards that are accepted globally:

  • NPT, ASME B 1.20.1: General-purpose pipe threads (inches).
  • G Series, ISO 228-1: Pipe threads for use where pressure-tight joints are not made on the threads. The internal and external threads are not tapered but are parallel or straight.
  • R Series, ISO 7/1: Pipe threads for use where pressure-tight joints are made on the threads. The internal thread is parallel (straight) or tapered; external is always tapered.

Notes

Japanese (JIS) valves and flanges are designated according to JIS standards.

European Norm flange types, such as flat-face and raised-face are designated Type A, Type B, Type C. These types do not correspond to the DIN 2526 Form A, Form D, etc., designations.

Common Size Designations
NPS1/23/411-1/222-1/2346810121416182024
DN15202540506580100150200250300350400450500600

Summary of Flange Terminology

 ASMEEuropean NormExample of Printed Presentation
Pressure RatingCLASSPNCL300 or CL300, PN 40
SizeNPSDNNPS 2, DN 50
Pipe Threads (Internal or External)NPTNPT, G (Straight), R (Tapered)G 1/4, 1/4 NPT, 1/4 NPT Internal (or External)