high quality and large span modern quality prefab steel workshop  

Brief Introduction

Light steel structure building is a new type of building structure system,which is formed by the main steel framework linking up H section,Z section,C section or U section steel components,roof and walls using a variety of panels and other components such windows,doors,cranes,etc.Light steel structure building is widely used as warehouses,workshops,large factories...etc.

Characteristics 

1.Wide span: single span or multiple spans, the max span is 36m without middle column.

2.Low cost: unit price range from USD 30/m2 to USD 60/m2 according to customers request.

3.Fast construction and easy installation.

4. Long using lifespan: up to 50 years.

5.Others: environmental protection, stable structure, earthquake resistance, water proofing, and energy conserving.

Specification

1. Professional design and engineering team: Full solution for steel structure design.

2. Procurement and Manufacture for all material for prefabricated building. We have a professional procurement team to make sure all the materials are with good quality. And our factory operation under ISO/CE/SGS standard, to make sure the fabrication works with high technology.

3. Site management & Installation supervision, We could send our engineers to help for the installation supervision, you just need to prepare a team which know normal construction works will be O.K. 

KXD's H Section Manufacturing Equipment and Process
Steel plate cutting→H section assembly→Automatic welding-H section strengthening→Assembly→Manual welding→Shot blasting-Painting→
Storage

I.Steel plate cutting
The H section  steel plate should be checked again by the factory and shall be applied under the condition of up to design and specified requirements after checking. Steel plate cutting should be aimed at quality guarantee and material saving. For each process like plate cutting,H type assembly, components assembly and pre-assembly should be carried out by profession setting-out worker precisely on processing surface and assembly sample plates.To guarantee the accuracy of the components'geometrical dimension,tolerance of form and position, angle and contact surface,inspection is necessary by inspector after setting out.In order to ensure the cutting quality,the surface of the ultra-thick plate is subjected to the surface carburizing hardness test before cutting.The CNC cutting equipment is preferred for cutting.The high purity 98.0% acrylic gas and 99.99% liquid oxygen gas are used to guarantee the smoothness and flatness of the cutting surface without notches and slags.The groove is cut by a special imported cutting machine.

Equipment name: Portable CNC Fire-cutting machine
Model No.: CNCDG-1530
Application feature: steel plate cutting(5-100mm plate cutting thickness), beveling of the edge.Advantageous in small equipment and easy-to-move. Mainly for cutting regular and irregular small components and beveling of the plate.

Equipment name:Straight flame cutting machine
Model No.:DZCG-4000A
Application feature:steel plate cutting(5-100mm plate cutting thickness),Y flange plate, web plate cutting, effective cutting width: 3200mm

Equipment name:CNC cutting machine
Model No.:CNC-4000C
Application feature:steel plate cutting(5-100mm plate cutting thickness),Y flange plate,web plate and irregular component cutting,effective cutting width: 3200mm

Equipment name: Radial drilling machine
Model No.:Z3050*16/1 
Application feature:Maximum drilling diameter φ50mm,Mainly for processing of component bolt-connection holes

Equipment name:Puncher machine
Model No.:JH21-400
Application feature:Maximum stamping pressure-400 ton,Mainly for plate punching, blanking, bending and shallow stretching

Equipment name:Shearing machine 
Model No.:Q11Y-25*2500 
Application feature:cutting width 2500mm and cutting thickness 3-25mm

II.H section steel assembly
The assembly process is set up on the imported H section production line.4 hydraulic positioning system press firmly against between the upper/lower flange and web plates in position. The adjust the parallelism of the flange plates and perpendicularity between flange and web plates and get them fixed after. The fixing welding should adopt C02 gas shielded welding.

Equipment name:H section steel assembly machine
Model No.:Z20B
Application feature:mainly for H type assembly u,flange width 150-800mm,web height 160-2000 mm

III.Automatic welding
The H section steel members will be hoisted into the gantry-type submerged arc automatic welding machine for welding.The welding process should be carried out in accordance with specified welding sequence and regulation parameters.Preheating, which uses the electrical heaters, is necessary for the ultra-thick plates of components.The set temperature shall be determined based on the specified one.Please see factory welding process documents for detail.

Equipment name: Gantry-type submerged arc automatic welding machine 
Model No.:LHA5ZB
Application feature:Mainly for assembly welding of H section steel whose maximum cross section up to 800mm×2000mm

IV.H section steel strengthening machine
H section steel strengthening process: Correction of flange flatness by using H section steel flange plate strengthening machine.Flame-correct the perpendicularity between the H section flange and web plate under special circumstances and then correct the side bending of the H section steel. The flame temperature should be controlled under the range of 600~800ºC.

Equipment name:H section steel strengthening machine 
Model No.:YTJ60B
Application feature:Mainly for correcting the deformation of I beam or H section steel flange plate during welding process,flange width 200-1000mm, flange thickness≤60mm, web height≥350mm

Equipment name:H section flange strengthening machine
Model No.: HYJ-800
Application feature:Mainly for correcting the deformation of I beam or H section steel flange plate during welding process,flange width 160-800mm,flange thickness≤40mm,web height≥160mm

V.Simulated assembly of component
1.Get familiar with component shop drawing and technical requirements.
2.The model components need to re-check by related department after making and finalizing of the model components and then to assemble.
3.Accurate mark-up
4.Inspect the component after first assembly.For multi-group components, pre-assembly for the first group and then batch assembly after qualified test.

VI.Manual welding

VII.Shot blasting
Equipment name:10-ramming heads shot blasting machine
Model No.:QH1525  
Application feature:Mainly for shot blasting of section steels including H section steel, welded members and steel plate,10 ramming head; Machine entry size:1500Í2500 and member at 1200Í2000 size could pass the machine at once; up to Sa2.5 Grade.

VIII.Painting
The surface of the members should be in even,flat, glossy and full painting without manifest of cracking, peeling and pin holing.The color and coating thickness should also meet design requirements.If there is no certain requirements,the following standards should be followed:thickness is 150μm indoor while 125μm outdoor.The allowable deviation is -25μm.The allowable deviation of dry paint film thickness for each-time painting
Two coats of primer:thickness being40±5μm; Two coats of finish paint:thickness being 60±5μm.

Equipment name:Airless sprayer    
Model No.:CPQ9CA
Application feature: Derived capacity:56 L/min,Air consumption:50~1200 L/min.Mainly for surface paint of structural members, Pressure ration: 32:1

Process, fabrication and quality control standard on welding groove/beveling of steel structure
1. Purpose
To ensure the welding quality, meeting up the technical requirements of welded members and improve the standardization of our fabrication, we specially formulate this regulation.
2. Application scope
This manual apply for the design, fabricate and inspection of groove joint in terms of manual arc welding, CO2 arch welding, mixed gas arch welding, submerged arc welding and electroslag welding.
3. Design of welding groove
3.1 Key points on design welding groove:
In order to obtain quality groove, it is necessary to choose appropriate form of groove. The option of groove mainly depends on the thickness of base metal, welding method and craftsmanship requirements.The followings are the factors we need to consider:

1. minimize the amount of filler metal
2. easy for beveling
3. in convenience for welding operation and slag removal
4. After welding stress and deformation should be as small as possible

3.2 Groove direction:
We will consider the following factors for the groove direction:
A)in favor of welding process and removing slag and leave enough space for welding process on the fusion face
B)minimize the times of flip-flop during welding
C)way of fit-up in actual welding

3.3. Regulation on groove direction of members:

3.3.1 Butt welding on H section rafter/column (when CJP-complete joint penetration and single side fusion is required)
1) When there is no welding backing, the groove orientation on flange plates should be same and falls on the direction in favor of welding on web plats(same rules apply for the PJP situation). Please refer to illustration 1

2)When there is welding backing, we require the groove direction being outward for the flange plates(opposite direction for web plates) and still falls on the direction in favor of welding on web plates. Please refer to illustration 2
3)Butt-welding on construction site:we require all the grooves should be bevelled on the upper rafter/column when it comes to bolt connection for web plates(see illustration 3). For the scenario of welding on web plates, please refer to the illustration 4.
3.3.2 Box column(groove on itself).See illustration 5
4. Welding groove form
4.1. Mark on form and size of welding joint groove:
Example: Shielded metal arch welding, complete joint penetration, butt welding, I shape groove, welding backing and single side weld would be marked MC-BI-BS1
4.2. For the mark of welding method and penetration type, please see the following chart 1.
Chart 1 Mark on welding method and penetration type

Mark	Welding method	Penetration type
MC	Shielded metal arch welding	CJP-complete joint penetration
MP		PJP-partial joint penetration
GC	Shielded arch welding Self-shielded arc welding	CJP-complete joint penetration
GP		PJP-partial joint penetration
SC	Submerged arc welding	CJP-complete joint penetration
SP		PJP-partial joint penetration
SL	Electroslag welding

 4.3. For the mark of single, double side welding and backing material type, please see the following chart 2
Chart 2 Single/double side welding and backing material type mark

Backing material type		Single/double side welding
Mark	Material	Mark	Single/double side welding
BS	Metal backing	1	Single side welding
BF	Other backing	2	Double side welding

4.4. Mark on each part size of groove, see chart 3.
Chart 3 Size mark on groove

Mark	Size of each part on groove
t	Thickness of welding plate(mm)
b	Groove root gap or gap between two members(mm)
h	Groove depth(mm)
p	Groove roof face(mm)
α	Groove angle(º)

Applicable Codes