High-pressure piping frequently asked questions
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What are high-pressure-piping systems?The following are considered high-pressure-piping systems:
- steam-system piping designed to operate at more than 15 p.s.i.;
- high-pressure and high-temperature fluids designed to operate at more than 250 degrees Fahrenheit and 30 p.s.i. gauge used for heating; and
- ammonia (717) refrigeration-system piping.
- Bioprocess piping systems
What licenses are required to install high-pressure piping or fabricate for installation in Minnesota? A business must first employ an individual who has a master HPP pipefitter license. The business may then apply for a Minnesota high-pressure-piping contractor license. After the business has met these requirements, it may apply for a permit to install or fabricate high-pressure piping. The business must also employ licensed journeyworker pipefitters to install or fabricate the high-pressure piping.
Persons who are not licensed as a master pipefitter or journeworker pipefitter may assist in the installation of high-pressure piping systems under the direct supervision of a licensed pipefitter, if they are registered in an approved pipefitter apprenticeship program, or registered with CCLD as an unlicensed high-pressure-piping pipefitter.
Licensed master or journeyworker pipefitters may directly supervise no more than two unlicensed persons.
What are the requirements to become a licensed master pipefitter?An individual must have five years experience in the practical installation or fabrication of high-pressure-piping systems, apply for and be approved to take the master pipefitter exam, and receive a minimum score of 70 on the exam.
What are the requirements to become a licensed journeyworker pipefitter?An individual must have four years of experience in the practical installation or fabrication of high-pressure-piping systems, apply for and be approved to take the journeyworker pipefitter exam, and receive a minimum score of 70 on the exam.
What are the master/journeyworker pipefitter exams based on?Both examinations are drawn from the Department of Labor and Industry's high-pressure piping and code for power-piping systems: Minnesota Statutes Chapter 326B - sections 326B.90 to 326B.925 and Minnesota Rules Chapter 5230. This information is also available for purchase from Minnesota's Bookstore, 660 Olive Street, St. Paul, MN 55155, (651) 297-3000.
Are study guides available for these exams? 
Download the high-pressure-piping license examination guide. (PDF)
Other available study guides:
- ANSI/IIAR 2-2008 with addendums A and B; "IIAR Ammonia Refrigeration Piping Handbook"
- ASME BPE - 2012
- ASME B31.1-2012
- ASME B31.5 - 2013
- ASME IX – 2013
Where can I access the necessary forms for the examination?The a application and affidavit forms are available for download on this Web site or by contacting the Minnesota Department of Labor and Industry at (651) 284-5059
What are the differences among standard, time and material, and blanket permits?- A standard permit shall be applied for any time a contractor has a set bid and knows the costs of labor and material for a project.
- A time and material permit shall be applied for any time a contractor has a project that doesn't have a set bid price.
- AA blanket permit shall be applied for when a contractor is to receive multiple projects over the course of a calendar year at one location, such as a paper mill, power plant, sugar-beet plant, processing plant, etc.
What costs are to be included in the inspection fee formula on permits?All costs of labor and material for the installation/fabrication of the high-pressure-piping project are to be included. This includes the cost of material supplied by the owner of the facility of the project. There is a worksheet with the permit application form to assist you in the calculation of these fees.
