Valves are essential components in any marine or industrial system, responsible for regulating flow, pressure, and direction of fluids or gases. In sectors like oil and gas, petrochemicals, shipbuilding, power generation, and water treatment, valve reliability directly impacts system efficiency and safety.

As a trusted valves stockist and distributor in Singapore, Aik Soon Hardware believes in educating our clients on the products they depend on. In this article, we explore the complete valve manufacturing process—from raw material procurement to quality testing and shipping—to give you a clearer picture of the craftsmanship and precision behind every valve.

Step 1: Raw Material Selection and Sourcing

The journey of every valve starts with the selection of raw materials. This is a critical stage that determines the valve’s strength, resistance to pressure, corrosion resistance, and lifespan.

Common materials include:

• Stainless Steel (SS316, SS304): Ideal for corrosive marine and chemical environments.

• Carbon Steel (WCB, A105): High mechanical strength for industrial pipelines.

• Bronze and Brass: Suitable for water systems and lower pressure marine systems.

• Alloy Steel or Duplex Steel: Used in high-temperature or high-corrosion applications.

Quality Assurance:

• Spectrochemical analysis is performed to confirm material composition.

• Ultrasonic and radiographic testing detects internal defects.

• Mill Test Certificates (MTCs) are reviewed for compliance with international standards like ASTM, DIN, JIS, API.

Step 2: Forging or Casting the Valve Body

With raw materials selected, the next step is to form the basic structure of the valve. Depending on the application and design requirements, manufacturers use either casting or forging.

Casting:

• Metal is melted at high temperatures and poured into custom-designed sand, shell, or investment moulds.

• Suitable for complex shapes and high-volume production.

• Post-casting treatments include sandblasting, grinding, and stress-relief heat treatment to remove imperfections and reduce internal stress.

Forging:

• High-pressure mechanical or hydraulic presses shape heated metal billets into valve bodies.

• Produces stronger grain structures, ideal for high-pressure valves.

• Common in ball valves, gate valves, and check valves for demanding applications.

Step 3: Precision Machining of Valve Components

After casting or forging, each component undergoes high-precision machining to ensure tight tolerances and compatibility between moving parts.

Machined Parts Include:

• Valve body and bonnet

• Valve seat and disc/gate/ball

• Stem and actuator housing

• Flanges, threads, and sealing faces

Machining Techniques:

• CNC milling and turning ensures repeatable accuracy.

• Drilling and boring create flow paths and seat areas.

• Surface grinding and lapping polish sealing surfaces to ensure zero leakage.

• Tolerances are typically within micron-level specifications to meet standards like API 6D, EN 12266, or ISO 5208.

Step 4: Valve Assembly

In a clean and controlled environment, skilled technicians assemble the valve components.

Key Steps:

1. Insert the seat into the valve body.

2. Fit the disc, gate, or ball depending on the valve type.

3. Attach the stem, which connects to manual or automated controls.

4. Seal the valve using gaskets, O-rings, or metal-to-metal seating.

5. Secure the bonnet with bolts or welds, ensuring uniform torque for pressure containment.

Valve Variants:

• Ball Valves: Use a precision-drilled ball for full flow or shut-off.

• Gate Valves: Feature a wedge-shaped gate for isolating flow.

• Globe Valves: Designed for flow regulation and throttling.

• Butterfly Valves: Lightweight and ideal for space-constrained pipelines.

Step 5: Rigorous Testing and Quality Control

No valve leaves the factory floor without undergoing extensive testing to ensure performance under real-world conditions.

Common Tests Include:

• Hydrostatic Shell Test: High-pressure water is applied to test the integrity of the valve body and bonnet.

• Seat Leakage Test: Evaluates sealing tightness using water, air, or nitrogen.

• Air Leak Test: Compressed air is used to detect even micro-leaks around seals and packing.

• Cycle Test: Valves are operated thousands of times to test durability and actuator strength.

• Fire Safe Testing (for some models): Exposes valves to flame conditions to verify sealing under extreme heat.

Each test is documented and certified in accordance with international standards such as:

• API 598

• BS 6755

• EN 12266-1

• MSS SP-61

Step 6: Surface Treatment and Finishing

To extend lifespan and protect against corrosion, valves are coated or treated based on their end-use environment.

Surface Finishing Options:

• Epoxy Coating: Durable finish for valves used in water and wastewater systems.

• Galvanising or Zinc Plating: Offers protection in corrosive marine settings.

• Passivation: Removes surface contaminants from stainless steel.

• Polishing or Electropolishing: Increases corrosion resistance and improves hygiene for food-grade or pharmaceutical applications.

Step 7: Marking, Packaging, and Logistics

With the valve assembled, tested, and coated, it’s ready for marking and shipment.

Valve Marking Includes:

• Manufacturer name or logo

• Valve type and model number

• Pressure rating (e.g., PN16, ANSI 150)

• Size and material (e.g., DN50, SS316)

• Heat number and test certification

Packaging:

• Bubble wrap or VCI paper for corrosion protection

• Foam-padded boxes or wooden crates

• Each shipment includes:

  • Test certificates

  • Compliance documents

  • Operating manuals (for actuated valves)

At Aik Soon Hardware, we stock ready-to-ship valves in Singapore to ensure fast delivery for time-critical projects.

Conclusion: Trusted Quality from Start to Finish

The manufacturing of industrial and marine valves is a highly-engineered, quality-driven process. Each valve goes through rigorous material selection, forging or casting, precision machining, meticulous assembly, and performance testing before it’s deemed fit for use.

At Aik Soon Hardware, our long-standing partnerships with leading global manufacturers ensure we supply only certified, reliable, and high-performance valves for a variety of industries in Singapore and across Southeast Asia.

Need help choosing the right valve for your system?

Contact Aik Soon Hardware today to speak with our technical specialists, or explore our wide selection of marine and industrial valves in our online catalogue.