jcb JS200 Service Manual page 269

Section E
31 - 1
Precautions During Use
Installation
• Be careful that excessive force is not put on the valve by the piping.
• Tighten the installation bolts in the same manner.
• When welding work is done near the installation bolts, excessive heat or spatter can damage the seals, so be careful.
• To prevent foreign matter from entering the ports, do not remove the plugs from the ports until installation.
Running
• Operate only after confirming that the hydraulic circuit and hydraulic oil are clean.
• Use the hydraulic oil specified in this manual.
• Do not raise the pressure of the main relief valve or port relief valve set pressure.
• The difference between the main relief valve and port relief valve set pressure should be more than 2.0 MPa (20 kgf.cm
• Perform warming up sufficiently before beginning actual operations.
In particular, to prevent sticking of the main spool due to heat shock because of low temperature of the hydraulic oil and valve at
starting, be careful of the following points.
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1. When operating the services, do not induce overload or full travel conditions which will cause sudden and frequent
operation of the relief valves. Operate steadily, enabling the hydraulic oil in the rams to circulate and warm each part
uniformly.
2. Fine and combined operations cause heat build up, so do not perform sudden operations at low temperatures.
9803/6400
Hydraulics
Control Valve JS200/JS240
Section E
31 - 1
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Issue 2*