ISO 15761 Standard Manufacturing Process for Gate Valves
# ISO 15761 Standard Manufacturing Process for Gate Valves
## Introduction to ISO 15761 Standard
The ISO 15761 standard specifies the requirements for the design, manufacturing, and testing of steel gate valves used in petroleum, petrochemical, and related industries. This international standard ensures that gate valves meet stringent quality and performance criteria for critical applications.
## Key Stages in the Manufacturing Process
### 1. Material Selection and Preparation
The manufacturing process begins with the careful selection of materials according to 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 thorough inspection and testing before being approved for production.
### 2. Casting or Forging Process
Manufacturers typically use one of two primary methods to create valve bodies:
– Sand casting for complex shapes
– Forging for higher strength components
The casting process includes:
Pattern making → Mold preparation → Melting and pouring → Cooling → Removal from mold → Cleaning and finishing
### 3. Machining Operations
Precision machining ensures all components meet dimensional tolerances specified in ISO 15761:
– CNC turning for body and bonnet machining
– Milling for flange faces
– Drilling and tapping for bolt holes
– Grinding for sealing surfaces
### 4. Assembly Process
The assembly stage involves:
– Installing the gate and stem
– Mounting the bonnet with proper gaskets
– Adding packing material for stem sealing
– Installing the handwheel or actuator
### 5. Testing and Quality Control
ISO 15761 mandates rigorous testing procedures:
– Shell test (1.5 times design pressure)
– Seat leakage test
– Backseat test
– Operational torque test
– Material verification tests
## Advantages of ISO 15761 Compliance
Manufacturing gate valves according to ISO 15761 offers several benefits:
– Ensures reliability in harsh operating conditions
– Provides international recognition and acceptance
– Standardizes quality across manufacturers
– Reduces failure risks in critical applications
– Facilitates global procurement and interchangeability
## Conclusion
The ISO 15761 standard provides a comprehensive framework for manufacturing high-quality gate valves that meet the demanding requirements of the petroleum and petrochemical industries. By following this standardized process, manufacturers can produce valves that offer superior performance, longevity, and safety in critical applications worldwide.