In industries like oil and gas, plumbing, and structural construction, the reliability of steel pipes is non-negotiable. While hydrostatic testing is common, air tightness testing plays an equally vital role in ensuring leak-free performance—especially in pipes used for low-pressure or gas-related applications.
What Is Air Tightness Testing?
Air tightness testing involves sealing both ends of the steel pipe and introducing compressed air under controlled pressure. The pipe is submerged in water, and any escaping air will create visible bubbles—indicating leakage.
This non-destructive testing method is fast, cost-effective, and ideal for detecting micro-leaks that water-based testing may miss.
Why Use Air Testing Instead of Water?
| Factor | Air Tightness Test | Hydrostatic Test |
|---|---|---|
| Medium | Air (dry) | Water (liquid) |
| Pressure Level | Lower to moderate (≤1 MPa) | Medium to high (2–60 MPa) |
| Leak Visibility | Immediate (bubbles in water) | Requires sensors or visual check |
| Ideal For | Small-diameter & thin-wall pipes | Thick-walled high-pressure pipes |
| Cleanliness | No water residue, cleaner | Risk of corrosion if not dried |
Air testing is preferred when:
- The steel pipe is thin-walled and cannot withstand high water pressure.
- Dry and clean testing is essential (e.g. food-grade or medical pipe).
- The pipe will carry gases (oxygen, natural gas, nitrogen, etc.).
How Does the Testing Machine Work?
- Pipe Loading: Steel pipe is placed onto the test bench.
- End Sealing: Pneumatic or mechanical seals close both ends.
- Pressurization: Air is injected to a set pressure (e.g. 0.6 MPa).
- Leak Detection: The pipe is submerged or enclosed; bubbles or pressure drops reveal leaks.
- Cycle Completion: The result is recorded or flagged for retesting.
Modern airtightness testing machines include:
- Digital pressure sensors
- Programmable PLC control
- Visual indicators or automated alarms
- High-efficiency test cycles (10–30 seconds per pipe)
Quality & Safety Compliance
Air tightness testing meets standards such as:
- GB/T 3091, GB/T 13793 (China)
- ASTM A53, ASTM A106 (US)
- ISO 9001 leak testing protocols
Using certified airtightness testers ensures your steel pipes are compliant with international safety and export regulations.
Wuxi Marley Machinery Technology offers fully automatic steel pipe air tightness testing machines with customizable pressure settings and leak detection systems. Contact us today to request a quote or get a custom testing solution.