# ISO 15761 Standard Manufacturing Process for Gate Valves

## Introduction to ISO 15761 Standard

The ISO 15761 standard specifies the requirements for the manufacturing process of steel gate valves designed for petroleum, petrochemical, and related industries. This international standard ensures that gate valves meet strict quality, performance, and safety criteria for critical applications in demanding environments.

## Key Stages in the Manufacturing Process

### 1. Material Selection and Preparation

The manufacturing process begins with the careful selection of materials that comply with ISO 15761 specifications. Common materials include:

• Carbon steel (ASTM A216 WCB)
• Stainless steel (ASTM A351 CF8/CF8M)
• Alloy steel (ASTM A217 WC6/WC9)

Raw materials undergo rigorous testing for chemical composition, mechanical properties, and corrosion resistance before being approved for production.

### 2. Casting or Forging of Valve Components

Casting Process

For cast gate valves, the process involves:

1. Pattern making and mold preparation
2. Melting and pouring of selected alloys
3. Solidification and cooling
4. Removal of casting from molds

Forging Process

Forged gate valves are produced through:

1. Heating of billets to forging temperature
2. Shaping under high pressure
3. Heat treatment for improved mechanical properties

### 3. Machining and Finishing

All valve components undergo precision machining to achieve the required dimensions and surface finishes specified in ISO 15761. Critical machining operations include:

• Body and bonnet machining
• Seat surface preparation
• Stem machining
• Gate profiling

### 4. Assembly and Testing

Assembly Process

The assembly of gate valves follows strict procedures:

1. Installation of seats and seals
2. Gate and stem assembly
3. Bonnet attachment
4. Packing installation
5. Operational mechanism assembly

Testing Requirements

ISO 15761 mandates comprehensive testing including:

Test Type	Standard Reference
Shell Test	ISO 5208
Seat Test	ISO 5208
Backseat Test	ISO 5208
Operation Test	Manufacturer’s procedure

## Quality Control and Certification

The ISO 15761 standard requires manufacturers to implement a comprehensive quality management system throughout the production process. This includes:

• Material traceability
• Process control documentation
• Non-destructive testing (NDT) methods
• Final inspection and certification

Valves manufactured according to ISO 15761 must bear appropriate markings that include:

• Manufacturer’s name or trademark
• Pressure class designation
• Material designation
• Size designation
• Direction of flow arrow

## Conclusion

The ISO 15761 standard provides a rigorous framework for the manufacturing of high-quality gate