# ISO 15761 Gate Valve Manufacturing Process

## Introduction to ISO 15761 Gate Valves

Gate valves manufactured according to ISO 15761 standards are essential components in various industrial applications, particularly in oil and gas pipelines. These valves are designed to provide reliable shut-off capabilities and are known for their robust construction and durability.

## Raw Material Selection

The manufacturing process begins with careful selection of raw materials:

– Carbon steel or stainless steel for the valve body
– High-quality alloy steel for the stem
– Bronze or stainless steel for the gate
– Graphite or PTFE for sealing materials

## Manufacturing Steps

### 1. Casting or Forging the Valve Body

The valve body is created through either casting or forging processes:

– Casting: Molten metal is poured into molds to form the basic valve shape

– Forging: Metal is shaped under high pressure for superior strength

### 2. Machining Operations

Precision machining ensures proper dimensions and surface finish:

– CNC turning for external surfaces
– Boring operations for internal passages
– Drilling and tapping for bolt holes

### 3. Gate and Stem Manufacturing

The gate and stem undergo separate manufacturing processes:

– The gate is precision-machined to ensure proper sealing surfaces
– The stem is turned and threaded with high accuracy
– Surface treatments like hardening may be applied

### 4. Assembly Process

Components are carefully assembled following strict quality procedures:

– Installation of the gate between the body seats
– Stem insertion and packing gland assembly
– Bonnet attachment with proper gasketing

## Quality Control Measures

ISO 15761 gate valves undergo rigorous testing:

– Hydrostatic testing to verify pressure integrity
– Shell test to check body strength
– Seat leakage test to ensure proper sealing
– Functional testing of operation mechanisms

## Surface Treatment and Coating

Final surface treatments enhance durability:

– Shot blasting for surface preparation
– Painting with corrosion-resistant coatings
– Special coatings for extreme environments

## Packaging and Shipping

Finished valves are carefully packaged:

– Protective coatings applied to machined surfaces
– Wooden crates for transportation
– Proper documentation including test certificates

## Conclusion

The ISO 15761 gate valve manufacturing process combines precision engineering with strict quality control to produce reliable valves for critical applications. By following standardized procedures, manufacturers ensure consistent performance and long service life of these essential flow control components.