# ISO 15761 Manufacturing Process for Gate Valves

## Introduction to ISO 15761 Standard

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

## Key Stages in the Manufacturing Process

### 1. Material Selection and Preparation

Manufacturers begin by selecting appropriate materials according to ISO 15761 specifications. Common materials include:

– Carbon steel
– Stainless steel
– Alloy steel

Raw materials undergo thorough inspection and testing before being approved for production.

### 2. Casting or Forging Process

The valve body manufacturing typically involves either:

– Sand casting for complex shapes
– Investment casting for precision components
– Forging for high-strength requirements

Each method must comply with ISO 15761’s dimensional and quality standards.

### 3. Machining Operations

Precision machining transforms raw castings or forgings into functional valve components:

– CNC turning for accurate dimensions
– Milling for flat surfaces and slots
– Drilling and tapping for connection points

### 4. Assembly and Testing

The assembly phase includes:

– Installation of stem, gate, and sealing components
– Application of appropriate lubricants
– Torque verification of all fasteners

Rigorous testing follows assembly, including:

– Hydrostatic pressure tests
– Shell tests
– Seat leakage tests
– Operational torque tests

## Quality Control Measures

ISO 15761 mandates comprehensive quality control throughout manufacturing:

– Dimensional inspections at each production stage
– Material certification verification
– Non-destructive testing (NDT) methods:
– Radiographic testing
– Ultrasonic testing
– Magnetic particle inspection

## Surface Treatment and Finishing

Final processing steps include:

– Shot blasting for surface preparation
– Application of protective coatings
– Marking and identification per ISO 15761 requirements
– Final inspection and packaging

## Conclusion

The ISO 15761 manufacturing process for gate valves ensures reliable performance in critical applications. By adhering to this international standard, manufacturers guarantee that their products meet the highest industry requirements for safety, durability, and operational efficiency in petroleum and petrochemical applications.