# ISO 15761 Compliant Manufacturing Process for Gate Valves
## Introduction to ISO 15761 Standard
The ISO 15761 standard specifies requirements for steel gate valves designed for petroleum, petrochemical, and related industries. Compliance with this standard ensures that gate valves meet stringent quality, performance, and safety criteria for critical applications.
## Key Stages of the Manufacturing Process
### 1. Material Selection and Inspection
The manufacturing process begins with careful selection of materials that meet ISO 15761 specifications. Raw materials undergo rigorous testing for:
- Chemical composition verification
- Mechanical property testing
- Non-destructive examination
### 2. Forging and Casting Operations
Depending on valve size and pressure rating, components are either forged or cast:
- Forged components for high-pressure applications
- Cast components for larger sizes
- Precision machining to achieve tight tolerances
### 3. Machining and Finishing
Critical machining operations include:
- Seat and sealing surface machining
- Stem and gate precision turning
- Thread cutting for bolted connections
- Surface finishing to specified roughness values
## Quality Control Measures
### Non-Destructive Testing (NDT)
All critical components undergo NDT including:
- Ultrasonic testing for internal defects
- Magnetic particle or liquid penetrant inspection
- Radiographic examination for cast components
### Pressure Testing
Every valve undergoes rigorous pressure testing:
- Shell test at 1.5 times design pressure
- Seat leakage test per ISO 5208
- Backseat test for stem sealing
## Final Assembly and Documentation
The final assembly process includes:
- Proper lubrication of moving parts
- Installation of proper gaskets and seals
- Functional testing of operation
- Preparation of complete documentation package
Benefits of ISO 15761 Compliance
Manufacturing gate valves according to ISO 15761 provides numerous advantages:
- Assured quality and reliability
- Interchangeability with other compliant valves
- Global acceptance in oil and gas projects
- Reduced risk of field failures
- Compliance with international safety standards
By adhering to the ISO 15761 manufacturing process, valve manufacturers can deliver products that meet the highest industry standards for performance and safety in demanding applications.