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Remote control clamshell grab

2015-03-05 15:26
1. Grab Operating Instruction
1.1 When grab is working, the safety operation rules of the crane must be followed. To keep the moving board slide easily and the opening, closing mechanism work in order while operation, the grab must be kept perpendicularly and the gradient should be below 25°and 15°. Please be sure that the grab is placed smoothly.
1.2 Primary Use and Daily Use
Check the safety load of the crane.
Check if the tapered wedge, rope carpel have been installed correctly. If they are loose, please fasten them in time. If there are deformation, damage and abrasion, it should be changed.
Check if every joint of the fastening piece is tight and each pressure plate (plate against turning) of cardinal axis is loose.
Check oil level of cylinder. When being used at first time, loosen the oil ruler on drop tank to examine the height of the oil level. Now the piston rod should be retracted into cylinder completely. Oil height should approach the first notch level of the oil ruler. If oil level is lower than the first notch level, oil should be fueled in time.
Check if the plug wire of the storage battery is loose.
Hang the balance beam of the bucket grab on the crane hock.
Do no-load test. Every turning part can move flexibly. Grab bucket opening and closing mechanism work accurately during opening and closing; there is no oil seepage and oil leakage of the hydraulic system and the buffer is good.
Every hinge axis should be brimmed with grease.
When grab is operated, if there is any hindrance in opening and the closing, the operation should be stopped. After check, it can work.
1.3 Maintenance Downtime
When the grab is in downtime, it should be cleaned. Clear the material on the face plate of through beam, inside of mobile traverse and between every turning part. It can prevent the grab from being rusted and decayed to clean the material, garbage and inclusion. Every articulated joint should be full filled with grease. Fallen the sip block of the grab down to make the piston rod of cylinder retracted completely to avoid to be corroded for exposure. All the power should be cut off. If the storage battery is taken out, its plug should be completely covered to avoid sea-water corrosion. Cover the whole grab with weather cloth (prepared by the user) to prevent the electric devices and the hydraulic system in grab from sea-water corrosion. 
1.4 Reuse
Please obey all the rules in 2.2.
Check the grab to avoid the accident.
2. Transportation
After the grab is closed, and the piston rod of the cylinder and deck beam is fixed, it can be transported.
3. Maintenance and Repair
3.1 Maintenance
3.1.1 Each hinge joint should be filled with lubricating grease after 8 hours operation of the grab.
3.1.2 If the grab is partially rusty, it should be cleaned timely; and painting after derusting. The paints are zinc rich epoxy primer paint; chlorinated rubber second coat paint and acrylic acid modified chlorinated rubber coat paint.
3.1.3 Hydraulic oil replacement
After the first 500 hours’ work, the hydraulic oil of grab should be replaced. Later on, one replacement after every 1000 hours’ work. When replacing the oil, the cylinder should be in a state of closure. Firstly, put the container in the middle of the through beam; open the bottom cover and the oil drain cock of the cylinder let the hydraulic oil out. Fill the cylinder with the oil through air filter, the oil should be filled through petrol-feed pump, and purified by 5~10µm oil filter lest the impurity in the oil jam the spool of the single check valve, which makes the grab out of work. After oiling, loose the oil dipstick when the grab is in a state of no-load and opening, and make the sipping block run up and down repeatedly (no less than 10 circles) let the air in the cylinder and the pipeline out. After the exhaustion, check the oil level. The oil level should be closed to the first notch level of the oil dipstick; if not, add enough oil. At this time, the piston rod of the cylinder should totally indent into the cylinder barrel.
3.2 Daily examination and repair
3.2.1 Hydraulic cylinder examination and repair
Examine the fixed 6x2 bolts and nuts in the flange connection of the cylinder. Examine the piston rod nut lest looseness. Examine if the cylinder seal has severe penetration of oil or not.  
3.2.2 Hinge axis examination and repair
Oil duct of each hinge axis should be clear. If the oil-hole is clogged, it should be dredged and filled with oil. If bushes& bearings are broken and the abrasion of the inner bore is 20% more than the original dimension, it should be replaced.  
3.2.3 Bush examination and repair  
If abraded diameter of each bush is 20% less than the original diameter, the bushes should be replaced.
3.2.4Hydraulic oil
The hydraulic system of the grab adopts abrasive-resistant hydraulic oil----46# abrasive-resistant hydraulic oil (be equal to ISO HM-N46).
When the cylinder is being filled with abrasive-resistant hydraulic oil, the oil should be filled through petrol-feed pump, and purified by 5~10µm oil filter lest the impurity jam the spool of the single check valve, which makes the grab out of work. When being filled with oil, the slipping block should be put down to the lowest point, namely the piston rod of the cylinder totally indents into the cylinder barrel.