ISO 15761 Compliant Manufacturing Process for Gate Valves

# ISO 15761 Compliant 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. Compliance with this standard ensures that gate valves meet stringent quality, safety, and performance criteria. Manufacturers adhering to ISO 15761 demonstrate their commitment to producing reliable products for critical applications.

## Key Stages of ISO 15761 Compliant Gate Valve Manufacturing

### 1. Material Selection and Verification

The manufacturing process begins with careful selection of materials that meet ISO 15761 specifications. Common materials include:

• Carbon steel (ASTM A216 WCB)
• Low temperature carbon steel (ASTM A352 LCB)
• Stainless steel (ASTM A351 CF8/CF8M)

All materials undergo rigorous testing for chemical composition, mechanical properties, and corrosion resistance before being approved for production.

### 2. Casting and Forging Processes

Casting Process

For cast body gate valves, the manufacturing follows precise patterns and molds to achieve the required dimensions and surface finish. The casting process includes:

• Pattern making and mold preparation
• Melting and pouring of selected alloys
• Solidification and cooling under controlled conditions
• Removal of excess material (fettling)

Forging Process

Forged gate valve components offer superior mechanical properties. The forging process involves:

• Heating billets to precise temperatures
• Shaping using hydraulic presses or hammers
• Controlled cooling to achieve desired microstructure

### 3. Machining and Finishing

Precision machining ensures all components meet ISO 15761 dimensional tolerances:

• CNC machining of critical surfaces
• Thread cutting for stem and bonnet connections
• Seat and gate surface finishing to achieve required sealing
• Final inspection of all machined dimensions

### 4. Assembly and Testing

Assembly Process

Skilled technicians assemble components following strict quality procedures:

• Installation of stem, gate, and seats
• Proper alignment of all moving parts
• Application of appropriate gaskets and seals
• Torque verification of all bolted connections

Testing Procedures

Each valve undergoes comprehensive testing as per ISO 15761 requirements:

• Shell test (1.5 times design pressure)
• Seat leakage test
• Backseat test
• Operation torque verification
• Final visual inspection

## Quality Assurance Throughout the Process

ISO 15761 compliance requires implementation of a robust quality management system that includes:

• Material traceability from raw material to finished product
• In-process inspections at critical manufacturing stages
• Non-destructive testing (NDT) methods like RT, UT, MT, and PT
• Documented procedures and records for all manufacturing steps
• Final certification and marking according to standard requirements

## Benefits of ISO 15761 Compliance

Manufacturers who adhere to ISO 15761 standards provide customers with several advantages:

• Assured product quality and reliability
• Enhanced safety in critical applications
• Global