Torque/Tighten recommendations for hydraulic hose, pipes and fittings

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Tapered Thread Ports (NPT (ANSI B1.20.1), NPTF (SAE J476, ANSI B1.20.3), BSPT (BS21, JIS B 0203, ISO 7) or JIS “PT”, M-Keg (DIN 158))

The sealing is carried out through the threads. They have cone shape with and angle of 1º 47'. They use to be damaged due to overtightened. So it is recommended to be torqued with TFFT (Turns From Finger Tight). See recomended values below. Also it is recommended to apply anaerobic liquid pipe sealant around the male threads leaving the 2 first threads free of it in order to prevent system contamination. If TEFLON tape (PTFE) is used apply 1-1/2 to 2 turns in clockwise direction when viewed from the pipe thread end (the table below comes from Parker catalogue
Tapered Pipe
Thread Size
BSPT
NPTF
TFFT
1/8-28
1/8-27
2-3
1/4-19
1/4-18
2-3
3/8-19
3/8-18
2-3
1/2-14
1/2-14
2-3
3/4-14
3/4-14
2-3
1-11
1-11 1/2
1.5 - 2.5
1 1/4-11
1 1/4-11 1/2
1.5 - 2.5
1 1/2-11
1 1/2-11 1/2
1.5 - 2.5
2-11
2-11 1/2
1.5 - 2.5

JIC (Joint Industry Council) 37° flare fittings

Assembling this fitting results in a metal-to-metal seal made by the cone on the female adapter or tube flare seating onto the 37° flare on a male adapter. This metal-on-metal contact can deform the fitting’s nose over time and threaten reusability. If over-tightened, the problem can be compounded. That’s why FFWR (Flats From Wrench Resistance) is recommended in this assembly according to Parker Supplier (Parker catalogue). Other suppliers as Eaton Aeroquip recommends torque as it is showed in the following table (Eaton Aeroquip)
37º
Tube O.D. (in.)
Thread Size
Tube/hose Dash Size
Tube Connection FFWR (Parker)
Swivel Nut or Hose Connection FFWR (Parker)
Jam nut or straight fitting torque Nm (Eaton Aeroequip)
1/4
7/16-20
-04
2 1/2
2
15-16
5/16
1/2-20
-05
2
2
20-22
3/8
9/16-18
-06
2
1 1/2
24-28
1/2
3/4-16
-08
2
1 1/2
52-58
5/8
7/8-14
-10
1 1/2
1 1/2
77-85
3/4
1 1/16-12
-12
1 1/2
1 1/4
108-119
7/8
1 3/16-12
-14
1 1/2
1 1/4
-
1
1 5/16-12
-16
1 1/2
1
148-154
1 1/4
1 5/8-12
-20
1
1
173-182
1 1/2
1 7/8-12
-24
1
1
216-227
2
2 1/2-12
-32
1
1
334-352

Ferulok Flareless Bite Type Fittings

When properly assembled, the wedging action of the Ferulok design will cause the end of the tube to press firmly against the seat in the body. This action will cause the tube to develop a small indentation circumferentially on the bottom of the tube. This indentation serves as a good post assembly inspection criterion. Sealing occurs between the 24° cone of the fitting body and the hose swivel as shown. FFWR (Flats From Wrench Resistance) is the recommended method for all bite-type fittings. That’s because rebuilds can become a factor if the fittings are over-torqued.
24ºFerrule
Type
Turns
Already preset ferrule
1/6 to 1/4 from wrench resistance (lubricated)
Swivel nut assembly procedure (R6BU, C6BU and S6BU)
3/4 from finger tighten
Ferrule set
1-3/4 from finger tighten

Ermeto EO Metric Bite Type Fittings

The EO progressive ring fitting is a flareless metric fitting (for metric tube)that consists of a body, a progressive ring (ferrule) and a nut. On assembly, two cutting edges of the progressive ring “bite” into the outer surface of the tube ensuring the necessary holding power and seal for high operating pressures.
24ºFerrule
Type
Turns
Already preset ferrule
1/12 turn or 1/2 flat (30°) from wrench resistance (lubricated)
Ferrule set
1½ turns if using the fitting body (1-1/2 turns if using the hardened pre-assembly tool), oiled, from finger-tight or light wrench-resistant position.

EO-2 Metric Bite Type Fittings

The common feature of all EO-2 fittings is elastomeric seals on all joints. This assures leakfree operation without retightening — even under severe working conditions. Another breakthrough in bite-type technology is the simple assembly and cost-saving handling of the unique EO-2 Functional Nut. EO-2 is a true metric design according to 24° bite-type standards such as: ISO 8434-1, DIN 2353 or DIN 3861. It covers all three series (LL, L and S) of the broad EO tube fitting program.
24ºSealing RingRetaining RingEO2 Functional Nut
Type
Turns
Already set retaining ring
1/6 to 1/4 turns (= 1 to 1-1/2 flats) from wrench-resistant position.
Set retaining ring
1 to 1-1/2 turns from wrench-resistant position (Oiled)

O-Ring Face Seal Fittings

O-ring face seal fittings can, and should, be torqued to the recommended specifications. This is because the connection seal is made by an elastomeric seal against metal. The lack of metal-on-metal contact means that only the O-ring is being deformed in assembly and reassembly. This sealing method is very forgiving and, when assembled to the recommended torque specifications, will create a leak-free seal every.For brass, aluminum (and other soft metals) decrease torque value of the table below by 35%, however F.F.W.R. is the same. time.
O-ring
Tube O.D. (in.)
Thread Size
Tube/hose Dash Size
Tube Connection Torque (Nm)
Swivel Nut or Hose Connection FFWR
1/4
9/16-18
-04
25
1/2 to 3/4
3/8
11/16-16
-06
40
1/2 to 3/4
1/2
13/16-16
-08
55
1/2 to 3/4
5/8
1-14
-10
80
1/2 to 3/4
3/4
1 3/16-12
-12
85
1/3 to 1/2
1
1 7/16-12
-16
115
1/3 to 1/2
1 1/4
1 11/16-12
-20
150
1/3 to 1/2
1 1/2
2-12
-24
230
1/3 to 1/2
2
2 1/2-12
-32
510
1/3 to 1/2

DKOL (Dicht Kegel O-ring Leicht) ( in English Cone O-ring tighten Light) ; DKOS (Dicht Kegel O-ring Schwer ) (in English Cone O-ring tighten Heavy)

O-ring face seal fittings can, and should, be torqued to the recommended specifications. DIN 3865 - ISO 8434-4 / 12151-2 spec. specifies a female coupling with cone angle of 24° and an O-Ring fitted on the cone seat of the female, commonly identified as DKOL and DKOS. This connection type gives improved sealing performance to the coupled unions. There are light and heavy series, identification is made measuring both thread size and tube OD. This is because the connection seal is made by an elastomeric seal against metal. The lack of metal-on-metal contact means that only the O-ring is being deformed in assembly and reassembly. This sealing method is very forgiving and, when assembled to the recommended torque specifications, will create a leak-free seal every.O-RING should be slightly oiled. Values obtained empirically
24º
DKOL
Nominal diameter
Outer diamater
ISO Thread M Size
Torque (Nm)
05
6
M12X1.5
15
06
8L
M14X1.5
20
08
10L
M16X1.5
40
10
12L
M18X1.5
50
12
15L
M22X1.5
75
16
18L
M26X1.5
85
20
22L
M30X2
100
25
28L
M36X2
180
32
35L
M45X2
220
DKOS
Nominal diameter
Outer diamater
ISO Thread M Size
Torque (Nm)
05
8S
M16X1.5
40
06
10S
M18X1.5
50
08
12S
M20X1.5
60
10
14S
M22X1.5
75
12
16S
M24X1.5
90
16
20S
M30X2
100
20
25S
M36X2
180
25
30S
M42X2
270
32
38S
M52X2
400

Non-Adjustable SAE Straight Thread Port Assembly (SAE J1926)

All straight-thread port types should be torqued to the recommended specifications. Much like O-ring face seal ports, the O-ring used with straight thread ports is what makes the seal. Over-tightening can damage the fitting or the seal. That said, you should take care to tighten only to the recommended torque. Over-tightening can lead to damaged fittings or O-rings, cracked ports, and, most certainly, a compromised connection seal. Lubricate threads before assembly. Values in chart are for plated steel fittings in steel ports. For stainless steel fittings, use the upper limit of torque range. For brass and aluminum, decrease torque value by 35%.
O-Ring
Tube O.D. (in.) SAE Dash Size
Thread Size UN/UNF
Heavy Duty SAE J1926-2 Torque (Nm)
Light Duty SAE J1926-3 Torque (Nm)
2
5/16-24
-
10
3
3/8-24
-
18
4
7/16-20
35
29
5
1/2-20
41
32
6
9/16-18
47
40
8
3/4-16
81
70
10
7/8-14
100
85
12
1 1/16-12
183
183
14
1 3/16-12
237
237
16
1 5/16-12
271
271
20
1 5/8-12
339
339
24
1 7/8-12
414
414
32
2 1/2-12
508
508

Adjustable SAE Straight Thread Port Assembly (SAE J1926)

All straight-thread port types should be torqued to the recommended specifications. Much like O-ring face seal ports, the O-ring used with straight thread ports is what makes the seal. Over-tightening can damage the fitting or the seal. That said, you should take care to tighten only to the recommended torque. Over-tightening can lead to damaged fittings or O-rings, cracked ports, and, most certainly, a compromised connection seal. Lubricate threads before assembly. Values in chart are for plated steel fittings in steel ports. For stainless steel fittings, use the upper limit of torque range. For brass and aluminum, decrease torque value by 35%.For adjustable fitting do the following steps
  1. Back off lock nut as far as possible. Make sure back-up washer is not loose and is pushed up as far as possible.
  2. Screw fitting into port until the back-up washer or the retaining ring contacts face of the port. Light wrenching may be necessary. Over tightening may damage washer.
  3. To align the tube end of the fitting to accept incoming tube or hose assembly, unscrew the fitting by the required amount, but not more than one full turn
  4. Using two wrenches, hold fitting in desired position and tighten locknut to the proper torque value from the appropriate table
  5. Inspect to ensure that O-ring is not pinched and that washer is seated flat on face of port
Lock NutO-ringBack up washer
Tube O.D. (in.) SAE Dash Size
Thread Size UN/UNF
Heavy Duty SAE J1926-2 Torque (Nm)
Light Duty SAE J1926-3 Torque (Nm)
2
5/16-24
-
7
3
3/8-24
-
11
4
7/16-20
20
20
5
1/2-20
41
28
6
9/16-18
47
40
8
3/4-16
81
70
10
7/8-14
100
85
12
1 1/16-12
183
183
14
1 3/16-12
237
237
16
1 5/16-12
271
271
20
1 5/8-12
339
339
24
1 7/8-12
414
414
32
2 1/2-12
508
508

Port Assembly (ISO 1179 / DIN 3852-2) Straight Male Stud Fittings Form A for Sealing Washer

All straight-thread port types should be torqued to the recommended specifications. Much like O-ring face seal ports, the O-ring used with straight thread ports is what makes the seal. Over-tightening can damage the fitting or the seal. That said, you should take care to tighten only to the recommended torque. Over-tightening can lead to damaged fittings or O-rings, cracked ports, and, most certainly, a compromised connection seal. Lubricate threads before assembly. Values in chart are for plated steel fittings in steel ports. For stainless steel fittings, use the upper limit of torque range. For brass and aluminum, decrease torque value by 35%.
45ºSealing Ring
BSPP Thread G Torque
Series
Tube O.D.
BSPP Thread G Size
Torque (Nm)
L
6
1/8 - 28
9
L
8
1/4 - 19
35
L
10
1/4 - 19
35
L
12
3/8 - 19
45
L
15
1/2 - 14
65
L
18
1/2 - 14
65
L
22
3/4 - 14
90
S
6
1/4 - 19
35
S
8
1/4 - 19
35
S
10
3/8 - 19
45
S
12
3/8 - 19
45
S
14
1/2 - 14
65
S
16
1/2 - 14
65
S
20
3/4 - 14
90
S
25
1 - 11
150
S
28
1 - 11
150
S
30
1 1/4 - 11
240
S
35
1 1/4 - 11
240
S
38
1 1/2 - 11
290
S
42
1 1/2 - 11
290
Metric ISO Thread M Torque
Series
Tube O.D.
ISO Thread M Size
Torque (Nm)
L
6
M10X1
9
L
8
M12X1.5
20
L
10
M14X1.5
35
L
12
M16X1.5
45
L
15
M18X1.5
55
L
18
M22X1.5
65
L
22
M27X2
90
L
28
M33X2
150
L
35
M42X2
240
L
42
M48X2
290
S
6
M12X1.5
20
S
8
M14X1.5
35
S
10
M16X1.5
45
S
12
M18X1.5
55
S
14
M20X1.5
55
S
16
M22X1.5
65
S
20
M27X2
90
S
25
M33X2
150
S
30
M42X2
240
S
38
M48X2
290

Port Assembly (ISO 1179 / DIN 3852-2) Straight Male Stud Fittings Form B with Cutting Face

All straight-thread port types should be torqued to the recommended specifications. Much like O-ring face seal ports, the O-ring used with straight thread ports is what makes the seal. Over-tightening can damage the fitting or the seal. That said, you should take care to tighten only to the recommended torque. Over-tightening can lead to damaged fittings or O-rings, cracked ports, and, most certainly, a compromised connection seal. Lubricate threads before assembly. Values in chart are for plated steel fittings in steel ports. For stainless steel fittings, use the upper limit of torque range. For brass and aluminum, decrease torque value by 35%.
45ºMetal to metal seal
BSPP Thread G Torque
Series
Tube O.D.
BSPP Thread G Size
Torque (Nm)
L
6
1/8 - 28
18
L
8
1/4 - 19
35
L
10
1/4 - 19
35
L
12
3/8 - 19
70
L
15
1/2 - 14
140
L
18
1/2 - 14
140
L
22
3/4 - 14
180
S
6
1/4 - 19
55
S
8
1/4 - 19
55
S
10
3/8 - 19
90
S
12
3/8 - 19
90
S
14
1/2 - 14
150
S
16
1/2 - 14
130
S
20
3/4 - 14
270
S
25
1 - 11
340
S
28
1 - 11
330
S
30
1 1/4 - 11
540
S
35
1 1/4 - 11
540
S
38
1 1/2 - 11
700
S
42
1 1/2 - 11
630
Metric ISO Thread M Torque
Series
Tube O.D.
ISO Thread M Size
Torque (Nm)
L
6
M10X1
18
L
8
M12X1.5
30
L
10
M14X1.5
45
L
12
M16X1.5
65
L
15
M18X1.5
80
L
18
M22X1.5
140
L
22
M27X2
190
L
28
M33X2
340
L
35
M42X2
500
L
42
M48X2
630
S
6
M12X1.5
35
S
8
M14X1.5
55
S
10
M16X1.5
70
S
12
M18X1.5
110
S
14
M20X1.5
150
S
16
M22X1.5
170
S
20
M27X2
270
S
25
M33X2
410
S
30
M42X2
540
S
38
M48X2
700

BSPP (Thread G) Port Assembly (ISO 1179 / DIN 3852-2) Straight Male Stud Fittings Form E with ED sealing

All straight-thread port types should be torqued to the recommended specifications. Much like O-ring face seal ports, the O-ring used with straight thread ports is what makes the seal. Over-tightening can damage the fitting or the seal. That said, you should take care to tighten only to the recommended torque. Over-tightening can lead to damaged fittings or O-rings, cracked ports, and, most certainly, a compromised connection seal. Lubricate threads before assembly. Values in chart are for plated steel fittings in steel ports. For stainless steel fittings, use the upper limit of torque range. For brass and aluminum, decrease torque value by 35%.
45ºED sealing
BSPP Thread G Torque
Series
Tube O.D.
BSPP Thread G Size
Torque (Nm)
L
6
1/8 - 28
18
L
8
1/4 - 19
35
L
10
1/4 - 19
35
L
12
3/8 - 19
70
L
15
1/2 - 14
90
L
18
1/2 - 14
90
L
22
3/4 - 14
180
S
6
1/4 - 19
40
S
8
1/4 - 19
40
S
10
3/8 - 19
80
S
12
3/8 - 19
80
S
14
1/2 - 14
115
S
16
1/2 - 14
115
S
20
3/4 - 14
180
S
25
1 - 11
310
S
28
1 - 11
310
S
30
1 1/4 - 11
450
S
35
1 1/4 - 11
450
S
38
1 1/2 - 11
540
S
42
1 1/2 - 11
540
Metric ISO Thread M Torque
Series
Tube O.D.
ISO Thread M Size
Torque (Nm)
L
6
M10X1
18
L
8
M12X1.5
25
L
10
M14X1.5
45
L
12
M16X1.5
55
L
15
M18X1.5
70
L
18
M22X1.5
125
L
22
M27X2
180
L
28
M33X2
310
L
35
M42X2
450
L
42
M48X2
540
S
6
M12X1.5
35
S
8
M14X1.5
45
S
10
M16X1.5
70
S
12
M18X1.5
90
S
14
M20X1.5
125
S
16
M22X1.5
135
S
20
M27X2
180
S
25
M33X2
310
S
30
M42X2
450
S
38
M48X2
540

BSPP (Thread G) Port Assembly (ISO 1179 / DIN 3852-2) Straight Male Stud Fittings Form G (non adjustable) and H (adjustable) with retaining ring and O-ring

All straight-thread port types should be torqued to the recommended specifications. Much like O-ring face seal ports, the O-ring used with straight thread ports is what makes the seal. Over-tightening can damage the fitting or the seal. That said, you should take care to tighten only to the recommended torque. Over-tightening can lead to damaged fittings or O-rings, cracked ports, and, most certainly, a compromised connection seal. Lubricate threads before assembly. Values in chart are for plated steel fittings in steel ports. For stainless steel fittings, use the upper limit of torque range. For brass and aluminum, decrease torque value by 35%.
45ºRetaining RingO-RingLock nutBack up washer
BSPP Thread G Torque
Series
Tube O.D.
BSPP Thread G Size
Torque (Nm)
L
6
1/8 - 28
18
L
8
1/4 - 19
35
L
10
1/4 - 19
35
L
12
3/8 - 19
70
L
15
1/2 - 14
90
L
18
1/2 - 14
90
L
22
3/4 - 14
180
S
6
1/4 - 19
40
S
8
1/4 - 19
40
S
10
3/8 - 19
60
S
12
3/8 - 19
60
S
14
1/2 - 14
90
S
16
1/2 - 14
90
S
20
3/4 - 14
180
S
25
1 - 11
310
S
28
1 - 11
310
S
30
1 1/4 - 11
450
S
35
1 1/4 - 11
450
S
38
1 1/2 - 11
540
S
42
1 1/2 - 11
540
Metric ISO Thread M Torque
Series
Tube O.D.
ISO Thread M Size
Torque (Nm)
L
6
M10X1
18
L
8
M12X1.5
25
L
10
M14X1.5
40
L
12
M16X1.5
55
L
15
M18X1.5
70
L
18
M22X1.5
90
L
22
M27X2
180
L
28
M33X2
310
L
35
M42X2
450
L
42
M48X2
540
S
6
M12X1.5
35
S
8
M14X1.5
55
S
10
M16X1.5
70
S
12
M18X1.5
90
S
14
M20X1.5
125
S
16
M22X1.5
135
S
20
M27X2
180
S
25
M33X2
310
S
30
M42X2
450
S
38
M48X2
540
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