3 wave expansion joint Size 300*300
Metal expansion joints (also called compensators) are compensating elements for thermal expansion and relative movement in pipelines, containers and machines. They consist of one or more metal bellows, connectors at both ends, and tie rods that depend on the application. They are differentiated according to the three basic types of movement: axial, angular and lateral expansion joints. Expansion joints have usage in various sectors, like energy production, paper industry, chemical industry, water treatment, oil and gas. Expansion joints can be used wherever thermal movements or vibration occurs in pipelines.
In 1920, he applied for a patent for the first so-called flexible metal tube expansion joint, German Reichspatent No. 367 185, from 29 July 1920. From a technical point of view, this precursor of today’s expansion joints is a large, pressure-tight flexible metal hose with a defined, restricted freedom of movement. In the 1930s, the ‘metal hose’ or ‘flexible metal tube’ principle was replaced by the metal bellows as the central functional element. This design principle – metal bellows with connection pieces – is still the structural basis of modern metal expansion joints today.
In modern expansion joints, the metal bellows are often produced with a so-called multi-ply design. To increase both flexibility and stability, multiple thin plies of metal are layered to form the bellows walls. There are two basic design types: The multi-ply and the multi-walled bellows structure. The multi-ply structure consists of a pressure-tight, longitudinally welded outer and inner cylinder of stainless steel. In between these cylinders is an open, spiral cylinder which forms multiple plies depending on the design. The multi-walled structure consists of several concentric, longitudinally welded cylinders. Each cylinder forms a pressure-tight and closed “wall”.
The main advantages of multi-walled bellows:
- Resistance to high and very high pressures
- Large movement absorption
- Small dimensions
- Small adjusting force rates
- Optimal compensation in a very small space
- Early leak indication (in case of damage) via standard check hole
- Complete burst resistance
- Possibility of permanent leak monitoring in critical media
- Economical use of high-quality, corrosion-resistant materials such as Inconel, Incoloy, Hastelloy, titanium and Tantal
- Insulation against structure-borne noise up to 20 dB
This design has both technical and economic advantages. For example, the bellows can be constructed of different materials, such as high-alloy stainless steels for the pipes in contact with the medium (inside and/or outside), and low-alloy stainless steels for the intermediate plies.
SELECTION & TECHNICAL QUESTIONS
Q1: How do I select the right conveyor model? What information should I provide?
> To recommend the most suitable solution, please provide the following details:
> 1. Material type: What material are you conveying? (e.g., fly ash, wood chips, biomass pellets, bottom ash, etc.)
> 2. Material properties: Particle size, temperature, moisture content, abrasiveness
> 3. Capacity requirement: How many tons per hour (t/h) do you need?
> 4. Installation conditions: Conveying distance, incline angle, space limitations
> 5. Application industry: Which industry is this for? (e.g., waste-to-energy plant, biomass power plant, cement plant)
> You can also email us or contact us via WhatsApp. Our engineers will get back to you within 24 hours.
Q2: What is the difference between screw conveyors and chain conveyors? Which one should I choose?
> Both types have different applications:
> – Screw Conveyors: Best for powdery and small-grain materials (e.g., fly ash, cement powder). Good sealing performance, simple structure, low maintenance cost.
> – Chain Scraper Conveyors: Best for bulky, highly abrasive materials (e.g., bottom ash, municipal solid waste, biomass fragments). Supports multiple inlet and outlet points.
> – Bucket Elevators: Ideal for vertical or steep-incline material lifting.
> If you are not sure, tell us your material and working conditions, and our engineers will help you choose.
Q3: Can your equipment handle high-temperature materials? What is the maximum temperature?
> We can customize equipment according to material temperature:
> – Standard type: 0~80°C, carbon steel
> – Medium temperature type: 80~200°C, thickened wear-resistant liner
> – High temperature type: 200~400°C, special heat-resistant steel, optional cooling jacket
> Please tell us your material temperature, and we will recommend the most suitable material solution.
Q4: Are there any limits on conveying distance and lifting height?
> Standard design range:
> – Screw conveyor: Single section up to 70 meters; multiple sections can be connected for longer distances
> – Chain conveyor: Single machine up to 60 meters
> – Bucket elevator: Lifting height up to 50 meters
> We can also customize for extra-long distances or special angles. Contact us for detailed solutions.
Q5: Do you provide explosion-proof design?
> Yes. For explosive and flammable conditions such as pulverized coal and biomass dust, we offer:
> – Explosion-proof motors (Ex d IIB T4 standard)
> – Reserved openings for explosion vents / rupture discs
> – Fully sealed structure to prevent dust leakage
> Please specify your explosion-proof rating requirements.
CUSTOMIZATION & MANUFACTURING
Q6: Do you support customization? What is the lead time?
> Over 90% of our equipment is customized according to customer working conditions. Standard models take about 90–120days. Special customizations take 120–180 days, depending on configuration complexity.
Q7: What material options do you offer?
> Common materials include:
> – Carbon steel (Q235B): Standard working conditions
> – Wear-resistant steel (NM400/NM500): Highly abrasive materials
> – Stainless steel 304/316L: Food, chemical, corrosion-resistant requirements
> – Bi-metal wear-resistant composite plate: Extreme abrasion conditions
> We will recommend the most cost-effective material solution based on your material properties.
Q8: What certifications do you have?
> We hold the following certifications:
> – ISO 9001:2015 Quality Management System
> – ISO 14001 Environmental Management System
> – ISO 45001 Occupational Health & Safety Management
> – CE Certification (EN 1090 Steel Structure)
> If you need scanned copies of specific certificates, please contact us.
DELIVERY & LOGISTICS
Q9: Which countries do you export to? Do you have export experience?
> Our equipment has been exported to more than 20 countries worldwide, including:
> – Europe: Germany, France, Poland, Turkey, etc.
> – Southeast Asia: Singapore, Thailand, Indonesia, Vietnam, etc.
> – Middle East: Saudi Arabia, UAE, etc.
> – South America**: Brazil, Chile, etc.
> We are familiar with the full export process: packaging, customs declaration, and ocean freight. We can provide FOB, CIF, and other trade terms.
Q10: What is your packaging method? Is it suitable for long-distance ocean shipping?
> Export-standard packaging:
> – Large items / complete machines**: Rust prevention + waterproof film + fumigated solid wood pallet
> – Precision components: Wooden case with shock-absorbing filling
> – Random accessories: Categorized packing with detailed packing list
> All wooden packaging meets IPPC fumigation standards for direct customs clearance.
Q11: What is your minimum order quantity?
> We do not have a strict minimum order quantity. Single-unit orders are welcome. Bulk orders can enjoy more favorable pricing.
INSTALLATION & AFTER-SALES
Q12: Do you provide installation guidance? Do engineers need to come to site?
> We offer two service options:
> 1. Remote guidance: Detailed installation drawings and operation manuals, video guidance for installation (free of charge)
> 2. On-site service: Dispatch engineers to site for installation and commissioning (travel costs are additional)
> Most customers choose remote guidance. Our equipment is designed as a modular structure for easy installation.
Q13: What is the warranty period? What are the wearing parts?
> Standard warranty period is 12 months (from the date of arrival at port).
> Wearing parts list:
> – Chain / screw flights: Approximately 1–3 years, depending on material abrasiveness
> – Liners: Approximately 2–4 years
> – Bearings: Approximately 2–3 years
> We recommend ordering a wearing-parts spare kit together with your first order.
Q14: How do you solve problems during operation?
> We provide 7×24 technical support:>
> – Response within 24 hours for technical issues
> – Remote video troubleshooting guidance
> – Engineer on-site service when necessary
> – Common spare parts in stock for fast delivery
QUOTATION & COOPERATION
**Q15: How can I get a quote? How long does it take?
> Quotation process:
> 1. You provide material parameters, capacity, installation conditions, and other requirements
> 2. Our engineers evaluate and select the appropriate model
> 3. Formal quotation and technical proposal provided within 7 working days
> You can contact us via email, or the online inquiry form.
Q16: What are your payment terms?
> Standard payment terms:
> – 30% advance payment: After contract signing, to start production
> – 70% balance: Before shipment, or against copy of Bill of Lading
For long-term cooperative customers, more flexible payment terms can be negotiated.
Follow these 3 steps to find your ideal conveyor solution
Step 1: Identify Your Material Type
Different materials require different conveyor designs. Tell us what you are conveying:
| Material Category | Examples | Recommended Conveyor Type |
| Powder / Fine Granules | Fly ash, cement powder, lime powder | Screw Conveyor |
| Small Granules / Pellets | Biomass pellets, plastic granules, grain | Screw Conveyor / Belt Conveyor |
| Fragments / Chips | Wood chips, bark, agricultural residues | Chain Scraper Conveyor |
| Bulky / Abrasive | Bottom ash, slag, MSW, clinker | Chain En-Masse Conveyor |
| Vertical Lift | Any bulk material needs vertical transport | Bucket Elevator |
Step 2: Define Your Working Conditions
Please prepare the following parameters before contacting us:
| Parameter | Why It Matters | Example |
| Capacity (t/h) | Determines conveyor size and power | 10 t/h, 50 t/h, 100 t/h |
| Conveying Distance (m) | Determines machine length | 15m horizontal, 30m incline |
| Incline Angle (°) | Affects capacity and design | 0° horizontal, 30° incline |
| Material Temperature (°C) | Determines material grade | Ambient, 150°C, 300°C |
| Moisture Content (%) | Affects discharge design | Dry, damp, wet (needs dewatering) |
| Abrasiveness | Determines liner thickness | Low, medium, high |
| Application Industry | Determines certification needs | Power plant, cement, mining, recycling |
Step 3: Choose Configuration Options
Based on your answers above, our engineers will recommend:
Material grade — carbon steel / wear-resistant steel / stainless steel
Sealing type — open trough / fully enclosed / gas-tight
Drive system — motor power, gearbox brand, speed range
Auxiliary options — explosion-proof motor, cooling jacket, cleaning device, level sensors
Not Sure Where to Start?
Send us your basic requirements, and our engineers will design a customized solution for you — completely free.
Email: bootec@bootecgroup.com Response time: Within 24 hours
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