When severe weather strikes or a seismic event threatens to topple buildings in our communities, seismic and wind restraints can help protect people and property.
These load-bearing mechanical devices and assemblies play a critical safety role by helping to ensure that mechanical, electrical, and plumbing equipment does not break, move, fall or fail when subjected to earthquake forces or high-wind loads.
The success and strength of a restraint during a worst-case scenario begins with proper rating. And proper rating is determined through mechanical testing — ideally, by an independent, ISO-accredited lab.
Why Mechanical Testing of Restraints is Critical
When a restraint component or assembly fails, the results can be severe, including falling equipment, broken gas or medical lines, blocked exit routes, and loss of critical services — not to mention possible injuries or fatalities. In light of their potential lift-saving role, hands-on mechanical testing is needed to confirm that restraints will function when faced with anticipated design loads.
By assessing the strength and behavior of restraints in real-world applications, mechanical testing establishes a restraint’s safe working limits. Hands-on mechanical testing provides an added layer of assurance, beyond engineering analysis, by revealing how actual materials behave and fail.
Overview of the Restraint Testing Process
To enhance safety and consistency across industries, the American National Standards Institute and American Society of Heating, Refrigerating, and Air Conditioning Engineers developed ANSI/ASHRAE Standard 171-2017, “Method of Testing for Rating Seismic and Wind Restraints,” to define how restraint systems used on HVAC and mechanical equipment should be physically tested and rated. ASHRAE 171 establishes standardized test setups, controlled loading protocols, repeatable measurement methods, and failure and acceptance criteria.
The ANSI/ASHRAE 171 standard attempts to address the most common types of restraints in a way that aligns with design methodologies defined in modern building codes.
The goal of this type of mechanical testing is to realistically simulate seismic and wind forces under potential worst-case conditions. The basic steps involved in mechanical testing for seismic and wind restraints include the following:
- Install Restraints to Reflect Real-World Application
- Apply Static and/or Cyclic Forces
- Measure Load & Displacement
- Observe Failure(s) (e.g., fracture, rupture, slippage, loss of load-carrying capacity, excessive permanent deformation)
- Rate Equipment Based on Test Results
ASHRAE 171 allows two primary test methods:
Static Load Testing: Incremental loads are applied in one or more directions to simulate equivalent seismic and wind forces. The load is increased until either the rated load is achieved or failure occurs. Static load testing is the most common type of restraint testing.
Cyclic Load Testing: Loading and unloading cycles are repeated to simulate earthquake motion effects. Cyclic load testing is not typically required for wind restraint testing.
Engineers rely on ASHRAE 171 test data to compare products and select the proper restraint systems for their intended purpose. Test results also support compliance with various codes and to meet owner/official requirements.
Industries That Commonly Require Restraint Testing
For safety and compliance purposes, ANSI/ASHRAE Standard 171 is commonly mandated by owners and other authorities in high-stakes industries, including:
- Commercial Building Construction
- Hospitals & Healthcare Facilities
- Data Centers & Mission-Critical Facilities
- Industrial & Manufacturing Facilities
- Energy & Utility
- Educational Facilities
- Government & Public Infrastructure
- Laboratories & Other Specialized High-Risk Facilities
Location is another factor that can affect the need for restraint testing. Restraint testing requirements may be more stringent in geographic hotspots, such as high seismic regions like California and Japan, and high wind regions, such as the Gulf and Atlantic Coast.
Why You Should Choose an ISO-Accredited Provider
As the international gold standard for testing laboratories, ISO/IEC 17025 accreditation means a test laboratory has been formally evaluated by an independent accreditation body and proven competent to perform specific types of testing—including the kind of mechanical testing required by ANSI/ASHRAE Standard 171.
With ISO accreditation, customers can be assured of the following:
- Staff’s Technical Competence
- Validated Test Methods
- Use of Proper, Calibrated Equipment
- Accurate, Traceable, Repeatable Results
- Independence & Impartiality
ISO accreditation means the test data is trustworthy and will be accepted by engineers, owners and authorities. Testing done by an ISO-accreditation lab minimizes requests for retesting or disputes over test validity, and can reduce potential liability exposure in the unlikely event a failure does occur.
Without accreditation, there is no formal proof that a lab can perform these tests, or interpret the results, correctly.
Why Choose IIA?
IIA provides ISO 17025-accredited ANSI/ASHRAE Standard 171 testing to determine whether equipment restraints — including bolts, welds and materials — can withstand earthquakes or high-wind events. We use specialized structural testing equipment capable of applying controlled static and dynamic forces to assess three key areas:
- Strength of the Restraints: Do they break?
- Functionality Under Dynamic Loads: Does it work during and after cyclic shaking or wind gust fluctuations?
- Performance of Restraint Assemblies: Do they work as a system?
Providing expert Mechanical Testing is just one way IIA upholds our mission of Making the World Safer.
We are proud to be one of only a handful of labs to offer ISO-accredited testing of critical restraint systems. Our ISO 17025 accreditation reflects our commitment to upholding the highest testing standards and to the safety and compliance of our customers’ products.
Learn more about our Mechanical Testing Services.
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