Ultimate Guide to High-Quality Valve Procurement

Overview

Valves are important components in fluid transmission systems. They can block, conduct, regulate, prevent backflow, stabilize pressure, divert, or release pressure. When purchasing valves, it is important to consider factors such as pressure, temperature, drive method, size, and structure to ensure quality. SNBV FLOW specializes in making high-quality valves that meet diverse needs and ensure top performance.

Key Control Points

1. Procurement Requirements

The first key step in valve procurement is setting the technical requirements. The accuracy of this step directly affects the quality and performance of the product throughout design, production, testing, and delivery.

At SNBV FLOW, we analyze technical needs carefully. We consider factors such as size, pressure, drive type, and material for the job. We also document these needs thoroughly.

Working Environment

• External Environment: The environmental temperature decides the material selection. High temperatures might need heat-resistant alloy steel. Temperatures ranging from -19°C to 49°C can use standard stainless steel, but lower temperatures may require austenitic stainless steel. For acidic or corrosive environments, materials like 0Cr18Ni9 or 0Cr18Ni10Ti are chosen.
• Internal Environment: The working medium (liquid or gas) and its properties (corrosive, low/high temperature) significantly influence material selection. High-purity gases (e.g., oxygen, nitrogen, argon) require special processing such as degreasing and oil removal before assembly.

Nominal Diameter and Pressure

• Diameter and Pressure: Valves used in aerospace must have clean internal surfaces. The design complexity varies with diameter and pressure. Domestic high-pressure valves can reach up to 45MPa with a maximum diameter of DN100 and a minimum of DN4. For DN10 valves, pressure can go up to 200MPa, though limited to liquid mediums.

Drive Form and Materials

• Drive Types: Common drive types include manual (handle or handwheel), pneumatic, and electric drives. In corrosive environments, people prefer materials like galvanized carbon steel, stainless steel handwheels, or handles. Pneumatic valves typically use an operating pressure of 5MPa and require compact cylinder structures.
• Electric Solenoids: Electric solenoids need the right voltage and plugs should have locking devices to prevent detachment over time. For acidic environments, connections use stainless steel sleeves with spherical joints, or stainless steel flanges for larger diameters.

2. Design and Production

SNBV FLOW designs and selects materials based on the detailed technical requirements. This includes ensuring material grades, chemical compositions, and mechanical properties meet the standards. Review drawings meticulously during the approval process to avoid discrepancies.

Inspect castings or forgings again to confirm they meet technical and drawing requirements. You must reasonably choose tolerances, roughness, and positional accuracy to ensure feasibility and functionality. Assembly and testing ensure that valves are clean and pass pressure and airtightness tests before delivery.

3. Acceptance by Buyer

The buyer's inspection team conducts final acceptance tests, typically including airtightness and operational flexibility under specified loads. Due to stringent controls during design and manufacturing, valves should generally be free of external and internal leaks. SNBV FLOW supports buyers in conducting thorough inspections to guarantee the highest quality products.

Conclusion

In valve procurement, the buyer must provide detailed environmental and technical requirements. SNBV FLOW strictly adheres to these requirements throughout production, ensuring that each valve meets the highest standards. Effective communication between buyer and supplier is essential to ensure reliable and stable valve performance, meeting all usage requirements.

Detailed Steps in Valve Procurement and Production

Understanding the Environment

The working environment is a key factor in valve selection. For instance, if the valve operates in a high-temperature environment, heat-resistant materials such as alloy steel are necessary.

For standard conditions (between -19°C to 49°C), regular stainless steel may suffice. In extremely low temperatures, people prefer austenitic stainless steel because of its durability and resistance to cold. Special materials like 0Cr18Ni9 or 0Cr18Ni10Ti are required for acidic or corrosive environments to prevent corrosion and ensure longevity.

Specifying Diameter and Pressure

Design valves according to their intended pressure and diameter. For example, aerospace applications demand valves with clean internal surfaces and precise tolerances. High-pressure valves in domestic settings can handle pressures up to 45MPa, with diameters ranging from DN4 to DN100. DN10 valves can handle up to 200MPa pressure, but only with liquid mediums for safety and proper operation in specific applications.

Choosing the Right Drive and Materials

Valves can be operated manually, pneumatically, or electrically. Manual drives include handle and handwheel types, suitable for non-corrosive environments. In corrosive settings, materials such as galvanized carbon steel or stainless steel are used to prevent deterioration.

Pneumatic valves typically operate at pressures around 5MPa and must have compact, reliable structures. Electric solenoids must match the system's voltage and have secure connections to avoid detachment.

Ensuring Quality in Design and Production

SNBV FLOW ensures that every valve meets stringent technical requirements. During the design phase, all details are carefully reviewed to avoid errors. Materials are thoroughly inspected to confirm they meet the necessary grades, compositions, and properties. This step includes checking tolerances, surface roughness, and positional accuracy.

Precise Assembly and Rigorous Testing

Assembly precision is crucial. Valves must be free of any foreign matter to pass pressure and airtightness tests. Workers assemble each valve with meticulous care to ensure it meets the required specifications and standards. After assembly, we conduct thorough tests to make sure the valves do not leak and work well in specific conditions.

Final Acceptance and Inspection

The final step involves the buyer's inspection team. They conduct thorough tests, including airtightness and operational flexibility under load. SNBV FLOW ensures valves meet required standards with strict quality controls, offering reliable solutions for different applications.

Conclusion

In valve procurement, the buyer must provide detailed environmental and technical requirements. SNBV FLOW strictly adheres to these requirements throughout production, ensuring that each valve meets the highest standards. Effective communication between buyer and supplier is essential to ensure reliable and stable valve performance, meeting all usage requirements. SNBV FLOW produces valves that meet customer needs through strict quality control, ensuring satisfaction and reliability in every product.

FAQs

1. What factors determine the material selection for valves?
   • Environmental temperature, working medium, and whether the medium is corrosive or not.
2. How are valve diameters and pressures typically categorized?
   • The pressures vary depending on the diameter size, with aerospace applications needing extremely clean internal surfaces.
3. What are common drive types for valves?
   • Manual, pneumatic, and electric drives, with material selections tailored to the working environment.
4. Why is the re-inspection of materials necessary in valve production?
   • To ensure that castings and forgings meet the required standards for grades, chemical compositions, and mechanical properties.
5. What tests are conducted during the final acceptance of valves?
   • Airtightness tests and operational flexibility tests under specified loads.

SNBV FLOW is committed to producing high-quality valves that meet rigorous standards, ensuring reliable performance and customer satisfaction.