# 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. This international standard ensures that gate valves meet stringent quality, performance, and safety criteria for critical applications.
Manufacturers adhering to ISO 15761 must implement rigorous production processes that guarantee reliable operation under demanding conditions. The standard covers design, materials, testing, and marking requirements for these essential flow control components.
## Key Stages in ISO 15761 Gate Valve Manufacturing
### 1. Material Selection and Verification
The manufacturing process begins with careful material selection according to ISO 15761 specifications:
– Valve bodies typically use carbon steel or alloy steel forgings
– Trim materials must withstand specific pressure and temperature ranges
– All materials undergo chemical composition analysis and mechanical testing
### 2. Precision Machining Operations
CNC machining centers perform critical dimensional operations:
– Body and bonnet machining to exact tolerances
– Seat surface preparation for optimal sealing
– Stem machining with precise thread profiles
– Gate slot machining for smooth operation
### 3. Assembly and Quality Checks
The assembly phase includes multiple quality verification steps:
– Component cleaning and inspection before assembly
– Proper alignment of gate, stem, and seats
– Torque verification for all bolted connections
– Functional testing of handwheel operation
## Testing and Certification Requirements
ISO 15761 mandates comprehensive testing protocols:
### Pressure Testing
All valves undergo rigorous pressure tests:
– Shell test at 1.5 times maximum working pressure
– Seat leakage test according to API 598 standards
– Backseat test for stem sealing capability
### Non-Destructive Examination
Critical components receive additional inspection:
– Liquid penetrant testing for surface defects
– Magnetic particle inspection for ferromagnetic materials
– Ultrasonic testing for internal flaws in thick sections
## Final Preparation and Documentation
Before shipment, valves complete final preparation:
– Complete cleaning and preservation
– Application of protective coatings
– Proper packaging for transportation
– Preparation of complete certification package including:
– Material test reports
– Inspection and test records
– Certificate of compliance
## Benefits of ISO 15761 Compliance
Manufacturers following this standard provide significant advantages:
– Guaranteed performance in critical applications
– Interchangeability with other compliant valves
– Reduced risk of field failures
– Compliance with international procurement specifications
– Enhanced safety for operators and facilities
The ISO 15761 manufacturing process represents the gold standard for gate valve production in demanding industrial applications, ensuring reliability and longevity in service.