Pipe dimensioning for hydraulic systems

For a safe, agile and trouble-free piping system it is important to use the correct pipe dimension, type, material and coupling type for the application. Selecting the right pipe is all about finding the right quality and determining the optimal dimension (external dimension and material).

A pipe dimension which is too small causes a high flow rate, which has several harmful effects. On the pressure side, turbulence and increased friction can be created, which then results in large pressure drops and overheating. High temperatures may cause damage and wear to moving components, such as gaskets and hoses, which all contribute to shortening the products operational life span.   

Calculating the recommended internal pipediameter

Use the table to determine the recommended inner diameter for the specified flow rate. Avoid flow rates greater than 8 m/s as the force will be too great and may damage the pipe. The table is based on the following flow rates:

Pressure line
3 → 5 m/s

Return line 
2 → 4 m/s

Suction
1 m/s
Oil Flow Rates
Rørdimensjon O.D. x w.t.Oljegjennomstrømning (l/min)
Sug - 1,3 m/sTrykk - 5 m/sRetur - 3 m/s
6 x 1,0142
6 x 1,5121
8 x 1,0295
8 x 1,5264
8 x 2,0132
8 x 2,5121
10 x 1,04159
10 x 1,53127
10 x 2,0295
10 x 2,5264
12 x 1,551911
12 x 2,04159
12 x 2,53127
14 x 1,572917
14 x 2,062414
15 x 1,593420
15 x 2,072917
16 x 1,5104024
16 x 2,093420
16 x 2,572917
16 x 3,062414
18 x 1,5145332
18 x 2,0124628
20 x 2,0166036
20 x 2,5145332
20 x 3,0124628
20 x 4,093420
22 x 1,5228551
22 x 2,0207646
22 x 2,5186841
25 x 2,02710463
25 x 2,5259457
25 x 3,0228551
25 x 4,0186841
28 x 2,03513681
28 x 2,53212575
Oil Flow Rates
Rørdimensjon O.D. x w.t.Oljegjennomstrømning (l/min)
Sug - 1,3 m/sTrykk - 5 m/sRetur - 3 m/s
28 x 3,03011468
30 x 2,04115996
30 x 3,03513681
30 x 4,03011468
35 x 2,059226136
35 x 3,052198119
38 x 2,567257154
38 x 3,063241145
38 x 4,055212127
38 x 5,048185111
42 x 2,088340204
42 x 3,079305183
42 x 4,071272163
50 x 3,0119456274
50 x 5,098377226
56 x 8,593358215
60 x 3,0179687412
60 x 5,0153589353
65 x 8,5141543326
66 x 8,5147565339
73 x 3,02751058635
73 x 5,0243935561
73 x 7,0213820492
80 x 10,0220848509
90 x 3,54221622973
90 x 5,03921507904
97 x 12,03261255753
115 x 4,070126961618
115 x 15,044217161021
130 x 15,061223551413
140 x 4,5105140412425
150 x 15,088233912035
165 x 5,0147156583395
220 x 6,02649101896113
273 x 6,04173160519630

Pipe dimensioning for hydraulic systems

For a safe, agile and trouble-free piping system it is important to use the correct pipe dimension, type, material and coupling type for the application. Selecting the right pipe is all about finding the right quality and determining the optimal dimension (external dimension and material).

A pipe dimension which is too small causes a high flow rate, which has several harmful effects. On the pressure side, turbulence and increased friction can be created, which then results in large pressure drops and overheating. High temperatures may cause damage and wear to moving components, such as gaskets and hoses, which all contribute to shortening the products operational life span.   

Calculating the recommended internal pipediameter

Use the table to determine the recommended inner diameter for the specified flow rate. Avoid flow rates greater than 8 m/s as the force will be too great and may damage the pipe. The table is based on the following flow rates:

Pressure line
3 → 5 m/s

Return line 
2 → 4 m/s

Suction
1 m/s
Oil Flow Rates
Rørdimensjon O.D. x w.t.Oljegjennomstrømning (l/min)
Sug - 1,3 m/sTrykk - 5 m/sRetur - 3 m/s
6 x 1,0142
6 x 1,5121
8 x 1,0295
8 x 1,5264
8 x 2,0132
8 x 2,5121
10 x 1,04159
10 x 1,53127
10 x 2,0295
10 x 2,5264
12 x 1,551911
12 x 2,04159
12 x 2,53127
14 x 1,572917
14 x 2,062414
15 x 1,593420
15 x 2,072917
16 x 1,5104024
16 x 2,093420
16 x 2,572917
16 x 3,062414
18 x 1,5145332
18 x 2,0124628
20 x 2,0166036
20 x 2,5145332
20 x 3,0124628
20 x 4,093420
22 x 1,5228551
22 x 2,0207646
22 x 2,5186841
25 x 2,02710463
25 x 2,5259457
25 x 3,0228551
25 x 4,0186841
28 x 2,03513681
28 x 2,53212575
Oil Flow Rates
Rørdimensjon O.D. x w.t.Oljegjennomstrømning (l/min)
Sug - 1,3 m/sTrykk - 5 m/sRetur - 3 m/s
28 x 3,03011468
30 x 2,04115996
30 x 3,03513681
30 x 4,03011468
35 x 2,059226136
35 x 3,052198119
38 x 2,567257154
38 x 3,063241145
38 x 4,055212127
38 x 5,048185111
42 x 2,088340204
42 x 3,079305183
42 x 4,071272163
50 x 3,0119456274
50 x 5,098377226
56 x 8,593358215
60 x 3,0179687412
60 x 5,0153589353
65 x 8,5141543326
66 x 8,5147565339
73 x 3,02751058635
73 x 5,0243935561
73 x 7,0213820492
80 x 10,0220848509
90 x 3,54221622973
90 x 5,03921507904
97 x 12,03261255753
115 x 4,070126961618
115 x 15,044217161021
130 x 15,061223551413
140 x 4,5105140412425
150 x 15,088233912035
165 x 5,0147156583395
220 x 6,02649101896113
273 x 6,04173160519630