# ISO 15761 Standard 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 related industries. This international standard ensures that gate valves meet strict quality, performance, and safety criteria for critical applications in demanding environments.

## Key Stages of 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

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

### 2. Casting or Forging Valve Bodies

The valve body manufacturing typically follows one of two processes:

– Casting: Molten metal is poured into molds to form the valve body
– Forging: Metal is shaped under high pressure while in solid form

Both methods must meet ISO 15761 dimensional and quality requirements.

### 3. Machining and Finishing

Precision machining operations include:

– Turning and milling to achieve exact dimensions
– Drilling and tapping for bolt holes
– Surface finishing to ensure proper sealing surfaces

### 4. Assembly Process

The assembly stage involves:

– Installing the gate and stem components
– Adding packing materials for stem sealing
– Mounting the bonnet and other accessories
– Performing initial functional tests

## Quality Control Measures

### Non-Destructive Testing (NDT)

ISO 15761 requires various NDT methods:

– Radiographic testing
– Ultrasonic testing
– Liquid penetrant inspection
– Magnetic particle inspection

### Pressure Testing

All valves undergo rigorous pressure tests:

– Shell test to verify body integrity
– Seat test to ensure proper sealing
– Backseat test for stem sealing capability

## Final Inspection and Certification

Before shipment, each valve undergoes:

– Dimensional verification
– Functional testing
– Visual inspection

– Documentation review

Successful valves receive ISO 15761 certification, confirming compliance with all standard requirements.

## Benefits of ISO 15761 Compliance

Manufacturing gate valves to ISO 15761 standards offers several advantages:

– Ensured reliability in critical applications
– International recognition and acceptance
– Improved safety for operators and facilities
– Extended service life of valves
– Reduced maintenance requirements

The standard provides a comprehensive framework for producing high-quality gate valves that meet the demanding needs of the petroleum and petrochemical industries.