Burst Test for Filter Housing: Safety Factor Guide

Imagine the disaster that would occur if a filter in your system suddenly fails due to pressure fluctuations. How can you prevent such an event? The best way is to address the issue at the source. When purchasing filters, make sure to consider this risk in advance.

One of the most important factors to look at is the burst test of the filter housing. In this blog, you’ll gain valuable insights into the significance of burst test for filter housings.

Table of Contents

What Is Burst Test for Filter Housing?

Burst test is typically conducted on representative samples, with only filter housings serving as the test specimen during the test. By applying increasing internal pressure to the housing until it fails, the test verifies safety margins and identifies weak points.

The primary result of a burst test is the burst pressure, along with critical data on failure location and deformation behavior. By comparing the measured burst pressure to the actual working pressure, you can calculate the actual safety factor and verify whether the design meets its goals.

▶ Burst Test Pressure and Classifications

Burst test pressure is defined as the maximum pressure that a filter housing can sustain prior to rupture or failure. Serving as a key safety parameter, it offers an adequate safety margin to protect the system against sudden pressure spikes.

Burst test are usually classified into five types: hydraulic burst test, pneumatic burst test, dynamic burst test, static burst test, and high/low-temperature burst test.

▶ Burst Test Equipment

Burst test equipment is a benchtop testing unit equipped with a sealed structure, which is designed to contain filter housings during burst testing. It comprises three core components: a computer control unit, a power unit, and a test chamber.

Other critical integrated components are listed below:

Hydraulic/Pneumatic Burst PressureTest Bench
Pressure Source
Pressure Transducer
Burst Pressure Monitoring Device
Safety Equipment
Data Acquisition System(DAQ)
Flowmeter (optional)

Note: The filter housing shall be fixed with a mounting fixture to prevent movement or shifting during pressurization.

Safety equipment includes pressure relief valves, emergency stop buttons, and protective enclosures.

▶ Industry Standards and Specifications

Industry Standards: ISO 10771-1, ASME BPVC Section VIII Division 1
Test Pressure: up to 1,500 bar (22,000 psi)
Hold Period at intermediate steps: 5-15 mins(common industry practice)

Why Carry Out a Burst Test for Filter Housing?

⭕️ To Prevent Safety Accidents

Burst test gives us critical safety info by deliberately creating a controlled disaster. This info is used to improve designs and establish standards, thereby maximizing the prevention of potential accidents.

⭕️ To Evaluate Filter Design

Burst test evaluates weak points and design flaws, it also provides precise burst pressure data that can be compared against the design burst pressure, thereby validating filter quality.

⭕️ To Comply with Industry Standards

Regulatory authorities require filter housings to provide burst test reports. These reports demonstrate compliance with testing criteria, enabling users to verify the actual maximum pressure rating of the housing.

Burst Test Vs. Proof Test

Proof & Burst Pressure Testing

The main difference that sets them apart is whether they are destructive.

Proof test is a non-destructive test (NDT) that does not affect normal use. Proof tests include hydrostatic test and pneumatic test, and are typically performed at 1.5 times the filter housing’s maximum working pressure.

Burst test is a destructive test used on samples or for new housing designs. It validates the ultimate margin beyond proof test by pushing the housing to much higher, failure-level pressures to show its overall structural strength.

Burst Test Procedure

▶ Pre-Test Preparation

Place the filter housing inside the protective enclosure and attach the inlet and outlet ports to ensure that the test medium enters the filter housing without entrapped air.
Water, oil, hydraulic oil, or compressed gas with a temperature of at least 5°C are commonly used as the test medium.

▶ Pressure Application

Start the equipment and slowly pressurize to 4 times the design pressure at a rate not exceeding 0.1 MPa/s.

b.Maintain pressure for no less than 5 minutes, and then slowly pressurize until the filter housing ruptures.

▶ Data Logging

Using high-precision pressure sensors, the equipment gathers pressure data in real time and displays it on the computer screen.
If a filter housing fails, the system notes the exact time and pressure of the burst. It also creates a pressure curve showing the sudden drop.

▶ Post-Test Analysis

If the filter housing breaks, leaks, or exhibits visible deformation, stop the test right away and document the incident.

Burst Pressure Vs. Design Pressure

Design pressure, or maximum allowable working pressure (MAWP), is the highest pressure at which a system can operate safely.

Burst pressure, also known as failure pressure, is usually 6 to 7 times the design pressure. Safety factor, which must be at least 4, is the ratio of burst pressure to design pressure. Safety factor of 4 means that design pressure of a filter housing is 25 bar if the burst pressure is 100 bar.

How to Select the Safest Filter Housing for Your System?

MAWP of the filter housing you select must exceed the system’s highest anticipated working pressure, with a safety factor of at least 4.
Make sure the housing material is appropriate for the kind of medium, temperature, and pressure in your system to ensure structural integrity.
Choose a trustworthy manufacturer and confirm that the filter housing is certified and satisfies burst test requirements.

Conclusion

As a pressure-bearing device, the filter housing needs to pass burst test. Thanks to the burst test’s accurate burst pressure, you’re able to clearly evaluate the filter housing’s pressure-bearing capacity. This verification ensures the filter housing can withstand additional impacts during use, thereby maintaining system integrity and safety.

FAQs

▶ Which Test Medium Is Better: Gas Media or Liquid Media?

Liquid media are preferred for they are safer than gas media.

Liquids have an extremely low compressibility coefficient. If the container ruptures, the pressure is released instantly, and the stored energy is minimal, so unlike a gas explosion, no explosive fragments are generated.

▶ Is Burst Test Necessarily a Destructive Test?

Not necessarily. When inspecting check valves, burst test is a non-destructive test. The safety factor of valves is inherently high, and burst test is only used to confirm that this safety factor exists, not to explore its limits.