Hitachi ZW 100-G, Workshop Manual

Page: 49 / 61

GENERAL / Tightening
W1-2-5
Piping Joint
Pipe connection (metal joint)
(Union Nut Wrench size 17, 19, 22, 27)
Metal (3) of adapter (1) and pipe (2) seals pressure
oil.
•
Precautions for use
Do not damage sealing surfaces (4) and (5) when
disassembling and assembling.
Tightening Torque
Use the specified tightening torque in the table below.
Wrench Size (mm) 17 19 22 27
N
⋅
m 24.5 29.5 39 78
(kgf
⋅
m) 2.5 3 4 8.0
Tightening
Torque
(lbf
⋅
ft) 18 22 28.5 58
O-Ring Seal Joint
O-ring (6) is installed against the end surface of
adapter (7) and seals pressure oil.
IMPORTANT:
•
Replace O-ring (6) with a new one when
reinstalling.
•
Before tightening union nut (9), confirm that
O-ring (6) is seated correctly in O-ring groove
(8). Tightening union nut (9) with O-ring (6)
displaced will damage O-ring (6), resulting in
oil leakage.
•
Do not damage O-ring groove (8) of adapter
(7) or sealing surface (10) on the hose side.
Damage to O-ring (6) may cause oil leakage.
•
If union nut (9) is found to be loose, causing
oil leakage, do not tighten it to stop the leak.
Instead, replace O-ring (6) with a new one,
then tighten union nut (9) after confirming that
O-ring (6) is securely seated in O-ring groove
(8).
M1M7-07-005
M104-07-033
Wrench Size mm Tightening Torque
Union Nut N
⋅
m (kgf
⋅
m, lbf
⋅
ft)
19 30 (3.0, 22)
22 70 (7.0, 51)
27 95 (9.5, 69)
32 140 (14, 100)
36 180 (18, 130)
41 210 (21, 155)
46 210 (21, 155)
7 6 9
8 10
a
1 4 5 3 2
a - Joint Body