Crane Production Process of DQCRANES

Our cranes are mainly consisted of metal structure( which is assembled with main beams, side beams, platform, ladder, railings, and trolley frame, etc), machining parts, purchased parts ( such as, bearings, fasteners, standard parts, etc.),cooperation parts ( such as, the hook) and electrical spare parts, etc.

Main crane processing procetures

The production process of DQCRANES is showed as the following diagram:

Crane production process diagram

If you have any questions, please feel free to contact us by email at sales@cranesdq.com, WhatsApp/ Wechat: +86 18838184113. We can process Types of cranes for you at an affordable price, including single girder overhead crane, double girder overhead crane, gantry crane, jib crane, electric hoist, etc. 

Metal Structure Production Process of DQCRANES

1. Incoming material inspection: The incoming materials, such as steel and welding material, will be checked according to related national standards in terms of quality, chemical composition, mechanical strength, etc.
2. Pretreatment of steel surface: The pretreatment of steel structure includes shot blasting and ball blasting to remove the rust, which will make the surface of important parts reach a degree of Sa2.5 of GB8923 standard.
3. Primer Painting: Primer will be painted right after the shot and ball blasting to avoid rusting.
4. Marking off: Mark the shape and processing lines on the plate with a sample plate, handrail, or diagram.
5. Plate-cutting: Plates will be cut by CNC cutting, semi-automatic cutting, shearing, and sawing.
6. Plate welding: Plates will be welded together according to requirements by semi-automatic cutter and automatic submerged-arc welding.
7. Flaw detection: The butt weld seams will be detected by the ray and ultrasonic.
8. Leveling: Level the plate after connecting.
9. Secondary mark, cutting: Mark the plate off by drawing cutting lines according to the required shape and size, and cut them with the semi-automatic cutting machine after connecting, detecting, and leveling. 
10. Assemble: Assemble the plates and profiles into the metal structure of the crane by welding.
11. Flaw detection: The butt weld seams of the main parts will be detected again.
12. Assembly (assemblage): Assemble each part according to requirements, and special attention is needed to the distance between the centers of two tracks and the length tolerance of crane bridge diagonal line when the main girder of crane and end carriage are connected into crane bridge.

Metal structure of a double girder overhead crane

Machining Parts Production Process of DQCRANES

1. Rough parts: They mainly include cast steel (ZG270-500, ZG340-640, etc.), iron casting (HT, QT), welding parts (steel plate and welding parts), and round steel parts (cut by saw machine).
2. Machining: The mechanical components will be processed by milling, planning, grinding, boring, drilling, insertion, etc., to change the shape, size, surface roughness and eventually make them into qualified ones.
3. Electric Assembly: Assembled by electrician.
4. Bought out items: Items such as motor, reducer, bearing, standard fastener, electrics and other standard parts will be bought according to the configuration table prepared by dthe esigning department and the schedule made by process department, which will be assembled according the drawing.
5. Cooperation parts: The cooperation parts refer to those such as the cast steel, iron casting, forging and overall spare parts designed by DQCRANES and produced by other crane spare parts manufacturers, which will checked when they be transported into DQCRANES’ workshop.
6. General assembly of Crane: Assemble each part according to general drawing, such as the assembly of hoisting mechanism on trolley, pulley and support stand, traveling mechanism, etc. Some parts have to be removed for the sake of transportation, and assembled at site, but they have to be trial erected at the manufacturer’s site, set welding positioning block on appropriate location for positioning of the second assembly.
7. General Inspection of Crane: After general assembly, quality inspection will be conducted thoroughly according to the relevant standard and technical requirements, and an ex-work certification will be issued to the qualified one.
8. Painting: Paints will be selected according to the working environment of cranes.
9. Paint Inspection: It is the final procedure of crane production process, which includes the checks on film thickness, sag and crinkle, etc.
10. Crane Delivery: Transport the product to user.
11. Site erection
12. Acceptance

Crane processing and manufacturing for reference

Crane processing and manufacturing: cutting and welding

Crane processing and manufacturing: welding main beam

Process crane manufacturing: semi finished main beam

Crane processing and manufacturing: main beam painting;

Dongqi overhead crane manufacturing

Crane processing and manufacturing: 20 ton overhead crane fabrication

Dongqi gantry crane manufacturing

Crane processing and manufacturing: 50 ton gantry crane fabrication

Dongqi jib crane manufacturing

Crane processing and manufacturing: jib crane