Pressure relief valves must be tested based on a regular schedule and according to a strict set of requirements. Those requirements and schedules can vary based on industry, but they can also vary depending on which organization governs the safety regulations within that industry.
The ASME (American Society of Mechanical Engineers) sets one of the most well-known pressure relief valve testing standards across the United States.
What is the ASME?
The ASME or American Society of Mechanical Engineers is a not-for-profit organization of professionals that is dedicated to promoting the vital role of the engineer in society.
As a third-party not-for-profit organization, the ASME develops safe, unbiased codes and standards that work to create safer engineering environments for all. The ASME has safety standards and codes for various industries, but the one we will focus on in this article relates specifically to pressure relief valve testing standards.
What are ASME Pressure Relief Valve Testing Standards?
ASME pressure relief valve testing standards are a set of standards, requirements, and procedures that must be met when testing an ASME-certified pressure relief valve. These standards are primarily located in Section 1 and Section VIII of the ASME Boiler & Pressure Vessel Code.
Section I of the ASME Boiler & Pressure Vessel Code
Section I provides guidance and standards for pressure applications for boiler applications. A valve conforming to the requirements of Section I is identified by a National Board “V” stamp, and usually features two blowdown rings.
Section VIII of the ASME Boiler & Pressure Vessel Code
This code specifically refers to vessels that operate at pressures above 15 psig. Safety relief valves that conform to Section VII standards are identified by a National Board “UV” Stamp.
What Does Does the ASME Boiler & Pressure Vessel Code Recommend for Safety Valves?
To get the full, detailed instructions from ASME, you’ll need to be trained and certified on the Boiler and Pressure Vessel Code (BPVC), specifically Sections I and VIII. Specific training requirements can vary depending on the industry, the type of pressure relief valve being tested, and the valve’s location. That said, there are usually three categories of requirements for all ASME pressure relief valve standards.
Periodic Valve Testing
Every pressure relief valve must be tested at some interval of regularity. Testing ensures valves function normally, from opening at the appropriate pressure to releasing fully when they are actuated.
You’ll need to refer to the code directly to determine the best frequency for the type of valve being tested, but typical testing frequencies are:
- Every three years
- Every five years
- And per inspection history
The frequency of the testing required will depend on the importance of that pressure relief valve.
For example, valves that are in high-risk areas typically need to be tested more often, while those that can cause minimal damage or do not have a significantly negative impact may be tested less often.
ASME-Approved Valve Size
In addition to regular testing, ASME-certified valves must also be sized appropriately for the system they are installed in. In general, the valve’s outlet piping should be at least as large in diameter as the valve’s outlet, but again, specific requirements depend on the application. Refer to ASME’s testing standards for more details.
Appropriate Operating Pressure
ASME standards also call for the appropriate tank operating pressure for the pressure valve. As a rule, the operating pressure should be at least 10% below the set pressure of the valve for valves conforming to Section VIII standards, and at least 3% below the set pressure of the valve for those conforming to Section I standards. This is specific to ASME relief valves though, and again, it’s up to the valve technician to ensure that proper protocol is followed.
Ensure Your Valve Technicians Have the Appropriate Equipment to Meet Required Valve Testing Standards
In the end, regardless of what exact ASME pressure relief valve testing standards a valve must meet, it is up to the valve technician to ensure that the valve is in compliance. This means they are also responsible for sourcing the appropriate equipment and ensuring that valve tests are completed properly and according to those ASME standards.
If you’re looking for high-quality valve testing equipment that supports your valve technicians in the field, AccuTEST’s sophisticated inline pressure relief valve testing equipment delivers. Get in touch with our team to learn more about AccuTEST Systems.