Overhead Crane: how to choose the right overhead crane
When you choose an overhead crane for you workshop or factory, you should know Capacity, Lifting height, Span, Traveling Speed, Power, where you use it and lift what with overhead crane etc. All of these parameters can help overhead crane manufacturer quote you accurately.
According the working cycle of overhead crane, the using frequency of the crane include often interrupted using, busy to use, busier to use and buiest to use.
Service grade of crane(the using frequency )
| Service grade mark | Working cycle N (upper limit) | Remarks | Service grade mark | Working cycle N (upper limit) | Remarks |
|---|---|---|---|---|---|
| U0 | 1.6×104 | Don’t often use | U5 | 5×105 | Often interrupted using |
| U1 | 3.2×104 | U6 | 1×106 | Busy to use | |
| U2 | 6.3×104 | U7 | 2×106 | Busier to use | |
| U3 | 1.25×105 | U8 | 4×106 | Busiest to use | |
| U4 | 2.5×105 | Often use with light duty | U9 | >4×106 | Busiest to use |
One working cycle:Sling→lifting→traveling→down→unloading→Return to the original place with empty hook.
Calculating formula of total working cycles :N=3600YDH/tc
Y:Using age of crane(usually 20～30 years) D:Working days in one year(265 days)
H:Working hours in one day tc :One working cycle time(s),is related with working frequency.
Loading state grade of crane(The loading degree in lifting)
Loading state means the approached degree of usual lifting quality of crane to the rated lifting capacity
- Pi: The i time lifting quality.
- Pmax:Rated lifting capacity.
- ni:loading Pi action times
- N:Total working cycles
| Loading state | Load spectrum coefficient Kp | Remarks |
|---|---|---|
| Q1—light | 0.125 | Hardly lifting rated load, usually lifting light load. |
| Q2—middle | 0.25 | Sometimes lifting rated load,usually lifting middle load. |
| Q3—heavy | 0.5 | Often lifting rated load,usually lifting heavy-duty load |
| Q4—heaviest | 1.0 | Frequently lifting rated load. |
3、Working class of crane（GB、ISO） FEM standard：1Bm=A3 1Am=A4 2m=A5 3m=A6 4m=A7
| Loading state | Load spectrum coefficient Kp | Working class | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| U0 | U1 | U2 | U3 | U4 | U5 | U6 | U7 | U8 | U9 | ||
| Q1—light | 0.125 | A1 | A1 | A1 | A2 | A3 | A4 | A5 | A6 | A7 | A8 |
| Q2—middle | 0.25 | A1 | A1 | A2 | A3 | A4 | A5 | A6 | A7 | A8 | A8 |
| Q3—heavy | 0.5 | A1 | A2 | A3 | A4 | A5 | A6 | A7 | A8 | A8 | A8 |
| Q4—heaviest | 1.0 | A2 | A3 | A4 | A5 | A6 | A7 | A8 | A8 | A8 | A8 |
Overhead Crane use In Door
| Capacity,ton | 1 | 2 | 3 | 5 | 10 | 16 | 20 | 25 | 32 | 50 | 72 | ~550 |
| Normal Workshop, A3 | LDA Single Girder Overhead Crane | |||||||||||
| Low Clearance Workshop, A3 | LT Single Girder Overhead Crane | |||||||||||
| Normal workshop, A5 | Euro Style Single Girder Overhead Crane | |||||||||||
| Normal Workshop, A3 | LH Double Girder Overhead Crane | |||||||||||
| Normal Workshop, A5 | QD Double Girder Overhead Crane | |||||||||||
| Normal Workshop, A5 | Euro Style Double Girder Overhead Crane | |||||||||||
| Grab Crane for bulk material, A5~A8 | QZ Grab Bucket Overhead Crane | |||||||||||
| Magnet Crane for steel product, A6 | QC Magnet Overhead Crane | |||||||||||
| Explosion proof, A5 | QB Explosion Proof Overhead Crane | |||||||||||
| Foundry Crane, A7, A8 | QDY Foundry Casting Crane | |||||||||||
| Foundry Crane, A7, A8 | YZ Foundry Crane | |||||||||||
Gantry Crane Out Goor
| Capacity,ton | 1 | 2 | 3 | 5 | 10 | 16 | 20 | 25 | 32 | 50 | 72 | ~550/1000 |
| Normal Outdoor Use, A3 | MH Trussed Single Girder Gantry Crane | |||||||||||
| Normal Outdoor Use, A3 | MH Box Girder Single Girder Gantry Crane | |||||||||||
| Normal Outdoor Use, A5 | MG Trussed Girder Double Girder Gantry Crane | |||||||||||
| Normal Outdoor Use, A5 | MG Box Girder Double Girder Gantry Crane | |||||||||||
| Normal Outdoor Use, A5 | Euro Style Double Girder Gantry Crane | |||||||||||
| Grab Crane for bulk material, A5~A8 | MZ Grab Bucket Gantry Crane | |||||||||||
| Magnet Crane for steel product, A6 | MC Magnet Gantry Crane | |||||||||||
| Ship Factory, A5~A8 | Ship Building Gantry Crane | |||||||||||
| Port Use, A6~A8 | RMG Container Crane | |||||||||||
