McIntyre 320 - Hydraulic Relief Valve; 6.8. Hydraulic Relief Valve; Testing for Over-Pressure; Adjusting the Relief Valve Setting

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320/407/500/600.41912-ENG
6.8. Hydraulic Relief Valve
(See Illustration 7.3, Page 49)
Always switch off and isolate the Shear from the mains
electrical supply before maintenance.
The Hydraulic Relief Valve is incorporated into the Control Valve and is set by the
manufacturer and should not require adjustment, however if the Shear is not operating
properly and no other cause can be found then the Relief Valve setting should be checked
and if necessary adjusted.
6.8.1. Testing for Over-Pressure
With the Shear switched off and isolated from the mains electrical supply:
• Remove the Blanking Plug, Item 3.13, from the top of the Control Valve, Item 3.14.
• FitareducerttingconnectedtoaPressureGaugetothisportensuringallttings
are tight.
• Place a large item known to be higher than the cutting capacity of the Shear
between the Top and Bottom Jaws. Then turn on and start up the Shear.
• Keep a watchful eye on the Pressure Gauge slowly depress the Foot Pedal until
the Pressure Gauge reading stops rising, this is the Relief Valve setting.
Note: Do Not hold the Shear at high pressures for long periods of time
as this may cause the Electric Motor to stall.
• If the Pressure Gauge reading is above the Maximum System Pressure for the
Shear (See Section 3.4, Page 12), then the System Relief Valve must be reset
to the Maximum System Pressure. (See Section 6.8.2, Page 40)
• Before operating the Shear, switch off and isolate the Shear from the mains
electricalsupply,thendisconnectthePressureGauge,previouslytted,andret
the Blanking Plug to the Control Valve Port.
Note: A Pressure Gauge reading less than the Maximum System
Pressure should not be taken as requirement to readjust the Hydraulic
Relief Valve. Pressure loss elsewhere in the hydraulic system will also
give a low pressure reading (See Sections 6.1 on Troubleshooting and if
uncertain contact the Manufacturer).
6.8.2. Adjusting the Relief Valve Setting
• Follow the instructions in Section 6.8.1, Page 40, to install a Pressure Gauge
and check the Relief Valve Setting.
• If the Relief Valve Setting is:
» Above the Maximum System Pressure (See Section 3.4, Page 12)