QD is a professional flange manufacturer and supplier.
Functions and types of flange castings
Flanges securely connect pipes, valves, and other equipment. They ensure the joints are leak-proof, airtight, and liquid-tight. They must also withstand the pressure and temperature inside the pipes, as well as external forces.
Flange structural design: The sealing surface is crucial for leak prevention and must be flat and smooth. Bolt holes should be evenly distributed to ensure balanced force during connection. The thickness and material of the flange itself determine the pressure it can withstand.
Common types of flanges are as follows:
| Flange Type | Structural Characteristics | Applicable Scenarios |
| Flat welding flange | The flange neck is short. During welding, the pipe is inserted into the inner ring of the flange | Low – pressure and normal – temperature systems. Such as water supply and drainage, low – pressure steam pipelines |
| Butt welding flange | With a long neck. Adopt butt welding with the pipeline | High – pressure and high – temperature environments. Such as chemical reaction kettles, high – pressure steam pipelines |
| Blind flange | A disc structure without a central hole | Plugging at the end of pipelines, isolation for equipment inspection and repair |
| Socket welding flange | The pipe is inserted into the socket of the flange and then welded. Good sealing performance | Small – diameter and high – pressure pipelines. Such as instrument pipelines, hydraulic systems |
| Threaded flange | The inner ring of the flange has threads. Connected with the pipeline through threads | Scenarios not suitable for welding. Such as non – ferrous metal pipelines, low – pressure gas pipelines |
Flange casting materials and processes
In terms of material selection, QD always takes adaptability as the core. We provide solutions based on customer working conditions:
| Material Type | Characteristics | Advantages |
| Stainless Steel | Resistant to rust and high – temperature oxidation | Suitable for humid and corrosive medium environments. Long service life |
| Carbon Steel | High strength. Good plasticity | Excellent cost – performance ratio. Suitable for general industrial scenarios with normal temperature and low pressure |
| Alloy Structural Steel | Strong comprehensive mechanical properties | Can withstand impact and vibration loads. Suitable for heavy – duty mechanical connections |
| Low – temperature Steel | Stable toughness at low temperatures | Meet the requirements of low – temperature working conditions such as refrigeration and liquefied natural gas |
QD utilizes two core processes: investment casting and sand casting. This ensures a balance between flange quality and production efficiency.
- The investment casting process uses investment casting. The process includes mold making, wax pattern forming, shell manufacturing, smelting and pouring, and subsequent processing. This process accurately reproduces complex structures and achieves a high surface finish. It is suitable for small and medium-sized flanges with high precision requirements.
- The sand casting process uses a sand mold as the mold. The process includes sand mold preparation, assembly, pouring, and sand removal. This process is highly efficient and cost-effective, suitable for large flanges and mass production.
The flexible choice of these two processes allows QD to meet the production needs of flanges of varying specifications.
Tips: How to judge the quality of flange castings by appearance？
A high-quality flange surface should be flat and smooth. There should be no visible pores, cracks, or shrinkage. The sealing surface should have uniform, clear lines, no scratches or dents, and no burrs around the bolt holes. The hole diameter should be uniform and the overall color should be uniform. There should be no signs of localized oxidation or rust.
Core Competence of QD Flange Castings
| Advantage Dimension | Specific Embodiment | Customer Value |
| Source Control | Carefully selected raw materials + Intelligent batching system + Laboratory testing | Stable material quality. Reduce the risk of later – stage failures |
| Process Assurance | Fully automatic molding line + Precise pouring technology + CNC precision processing | High dimensional accuracy. Reliable sealing performance |
| Quality Inspection System | Professional testing equipment + Hydraulic pressure test + Anti – corrosion test | Product qualification is guaranteed. Meet the working condition requirements |
Tips: Several Criteria for Selecting a Reliable Supplier
A reliable flange supplier should possess:
- Complete production qualifications and industry certifications, demonstrating compliance and professionalism.
- Process strength, including advanced equipment and mature technology, to meet customized requirements.
- A comprehensive service system, including pre-sales technical consultation, in-sales production follow-up, and after-sales problem resolution.
QD has over 20 years of foundry experience. We have comprehensive qualifications and mature processes. We have our own independent factory and design team, and we can provide comprehensive technical support. We are a reliable partner that meets these criteria.
Choose to cooperate with QD
Guaranteed by Strength and Service
- Production Strength: Standardized production base + professional R&D team. Years of experience have resulted in mature technical solutions. We can cover all flange production needs, including flat-weld, butt-weld, and threaded flanges.
- Customized Service: Customized solutions are designed based on operating parameters and dimensional requirements. Flexible adaptation to diverse industry scenarios.
- Delivery Guarantee: Scientific production planning and supply chain management ensure on-time order delivery and avoid project delays.
- After-Sales Guarantee: Rapid response to issues. Technical support and solutions are provided.
The actual benefits that customers can gain
| Benefit Type | Specific Description |
| Risk Reduction | Stable product quality. Reduce shutdown losses caused by flange failures |
| Efficiency Improvement | Customized solutions. Improve equipment matching degree |
| Cost Savings | Full – process service. Optimize communication links. Cost – optimization suggestions can be obtained through long – term cooperation |
| Technical Support | Provide selection guidance and suggestions |
QD prioritizes customer needs. We provide reliable flange casting solutions for a wide range of industries. If you’re looking for a reliable flange supplier, contact QD. Let our professional team provide you with a customized solution.
FAQ
1. Where are flange castings primarily used?
Flanges are connecting components for pipes, valves, and other equipment. They enable removable connections between pipes or between equipment and pipes. They are widely used in industries such as petroleum, chemical, water conservancy, power, and municipal engineering.
2. How to choose between different flange types?
Choose based on pressure, temperature, and connection method:
Use flat-weld flanges for low pressure and normal temperatures.
Use butt-weld flanges for high pressure and high temperature.
Use socket-weld flanges for small diameters and high pressure.
Use threaded flanges for situations where welding is not possible.
Use blind flanges for pipe plugging.
3. Why do flanges leak?
Common causes include: uneven sealing surfaces, uneven bolt tightening, material incompatibility with the media (e.g., using ordinary carbon steel in a corrosive environment), or pores and cracks in the casting itself.
4. What materials are QD flange castings made of?
Main materials include stainless steel (corrosion and high-temperature resistance), carbon steel (cost-effective), alloy structural steel (impact resistance), and cryogenic steel (suitable for low-temperature environments). You can choose the material based on your application needs.
5. How can I tell if a flange is of good quality?
Appearance: The surface should be smooth and free of pores and cracks. The sealing surface should have uniform texture. The bolt holes should be free of burrs.
6. What should I look for when selecting a flange supplier?
Three key points to consider:
Whether the supplier has compliance qualifications and test reports.
Whether the process can meet custom requirements (such as QD’s precision casting/sand casting process).
Whether pre-sales selection guidance and after-sales support are provided.