How Does Plastic Valve Pressure Testing Work?

How Does Plastic Valve Pressure Testing Work?

Plastic valves are essential components in systems where chemical resistance, low weight, and corrosion protection are required. To ensure that these valves meet safety and performance standards, pressure testing is carried out during the manufacturing and quality assurance processes. Zhongshi, a company specializing in valve testing equipment, provides systems designed to carry out pressure testing efficiently and according to industry standards. This article explains how plastic valve pressure testing works and why it is important.

What Is Pressure Testing?

Pressure testing is a process used to evaluate the integrity and performance of a valve by exposing it to a specific level of pressure, typically higher than its normal operating conditions. For plastic valves, the goal is to ensure they can maintain internal pressure without leaking or deforming.

There are two main types of pressure testing for plastic valves: hydrostatic testing and pneumatic (air) testing.

Hydrostatic Pressure Testing

In hydrostatic testing, the plastic valve is filled with water and sealed. The valve is then subjected to a defined pressure using a test machine. The key steps include:

• Filling the valve with water.

• Applying pressure gradually using a hydraulic pump.

• Holding the pressure for a set time, usually in accordance with relevant standards.

• Monitoring for leaks at joints, seals, and the valve body.

Hydrostatic testing is widely used because water is non-compressible and offers a safer medium for high-pressure testing. Zhongshi’s equipment is designed to carry out this procedure with precision and consistency.

Pneumatic (Air) Pressure Testing

Air pressure testing uses compressed air instead of water. It is typically used when the valve cannot be exposed to water due to cleanliness requirements or material compatibility.

The process includes:

• Sealing the valve in a test chamber.

• Pressurizing with air to the required level.

• Checking for pressure drops or using leak detection tools like soap solution or electronic sensors.

Air testing is sensitive and can detect small leaks more easily than water-based methods. Zhongshi provides testing machines equipped with pressure gauges and safety controls for accurate pneumatic testing.

Additional Testing Considerations

• Test Pressure: The applied pressure is often 1.5 times the working pressure of the valve.

• Duration: The test duration can vary based on valve size and standards.

• Safety Measures: Pressure testing, especially with air, must be done with proper enclosures and safeguards.

Why Is Pressure Testing Important?

Pressure testing helps confirm that:

• The valve is free from manufacturing defects.

• It meets regulatory and customer requirements.

• It will perform reliably in actual service conditions.

Plastic valves that pass pressure testing are more likely to function effectively over their expected service life, reducing the risk of failure in the field.

Zhongshi’s Role in Pressure Testing

Zhongshi manufactures pressure testing machines suitable for various types of plastic valves. The company offers systems for both hydrostatic and pneumatic testing, designed to meet the needs of manufacturers and testing labs. The equipment is built to deliver stable performance and comply with common testing standards.

Pressure testing is a critical step in the quality assurance process for plastic valves. It involves applying hydrostatic or pneumatic pressure to ensure the valve can operate safely under expected conditions. Zhongshi supports this process by offering reliable and standard-compliant testing machines that help manufacturers verify valve performance before products reach the market.