ASME Certification FAQ

Question: What is ASME Certification and how is it acquired?
Answer:
  • ASME stands for the American Society of Mechanical Engineers. They are a standard and code writing
  • HLW stands for “Lined Potable Water Heaters”
  • H stands for “Heat Boilers Except Cast Iron” as well as “Cast Iron Sectional Heating Boilers”
  • Our C98 and R98 units are available ONLY with the HLW stamp, not the H stamp.
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    Question: What does the HLW stamp mean?
    Answer:

    The HLW stamp means that the certified device has been approved by the ASME for use as a water heater. Water heaters fall under ASME HLW jurisdiction if they meet any one of three criteria:

  • The device holds 120g or more of water
  • The device has a BTU input of 200,000 or more
  • The device operates at a pressure level of 160psi or more

    • The R98/C98 series meets the second criterion and so is subject to ASME certification. As a result, ASME put us through a rigorous certification program which tested the material integrity and safety of our unit to ensure that, as a 237,000 BTU unit, it is safe for operation. ASME performed the following evaluations:

    Material specs

  • ASME confirmed that the copper we use for the heat exchanger is the proper grade and type

    • Hydrostatic test

  • A pressure test to confirm performance at an operating pressure of 150psi

    • Safety check

  • ASME confirmed that our manual recommends the proper pressure release valve for our unit (the new WRIK-32C/F has a PRV rated for 2.7m BTUs)

    • Question: Does the HLW stamp mean that the R98/C98 can be used as a boiler?
    Answer: No. The HLW stamp just means that our unit has been certified as a 200,000 plus BTU water heater by ASME. The HLW stamp is not the same as the ANSI Z21.13 rating that boilers for closed loop hydronic applications have. The MAIN BENEFIT of the ASME rating is that there are many state and local authorities which require ASME certification if your unit is above 200,000 BTUs. Not all do, and some places only require ASME for commercial applications.
    Question: What about the National Board, or NB registration?
    Answer: Any unit which has a HLW stamp has its serial number registered with the National Board and so has an “NB” stamp as well. Some inspectors require this. They can use the National Board to look up the serial number of each unit with an HLW stamp and verify that it is indeed properly certified.
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