High Pressure Pipe -- Orbital Tube -- Mig -- Tig -- Stick Weld

High Pressure Pipe

Certified High Pressure Piping:

High pressure piping in Minnesota is saturated steam above 15 psi, and Ammonia refrigeration or any medium which is 30 psi and 250 degrees F.

 Medium example,   oil, water, etc.


    Subpart 1.  General requirements.  Specific reference to the following material is made in part 5230.1070.  Reference to this chapter in general, and to part 5230.1070, subpart 2 in particular, should be made before proceeding further in Appendix A of the ANSI code.  It is assumed that the manufacturer or contractor has an organization familiar with the various welding codes and capable of designing, engineering, and supervising welded construction.

    Each manufacturer or contractor is responsible for the welding done by the organization, and shall conduct the tests
required in this section to qualify the welding procedures being used in the construction of the weldments built under this code and the performance of welders and welding operators as defined in part 5230.1100 who apply these procedures, and shall maintain records thereof.

    Subp. 2.  Scope.  The following rules apply to the qualification of welding procedures and welder performance for
all types of manual, semiautomatic and automatic arc and gas welding processes permitted in other sections of the code.  These rules may also be applied in so far as they are applicable to other manual or machine welding processes.

    Subp. 3.  Definitions.  Some of the more common terms relating to welding are defined in the American National
Standard Code for Pressure Piping, Power Piping, published by ASME, 1983 edition, as amended.  These are in substantial agreement with the definitions of the American Welding Society, A 3.0 given in "Standard Welding Terms and their Definitions".

    Subp. 4.  Weld orientation.  The orientations of pipe welds with respect to horizontal and vertical planes of reference are classified in accordance with part 5230.1250, figure 8 into four positions.  These are flat, horizontal, vertical, and overhead.

    Subp. 5.  Welding positions for qualification tests.  Welding positions for qualification tests:

      A.  Test welds for both procedure qualification and performance qualification shall be made on groove welds in pipe in one or more of the specified basic qualification test positions shown in part 5230.1260, figure 9.  An angular
tolerance of ± 15 degrees from the specified horizontal and vertical planes shall be allowed in making the test welds.

      B.  Both procedure and performance qualifications on groove welds in pipe in a given position, shall also qualify for groove welds in plate and fillet welds in pipe and plate for equivalent welding positions as shown in part 5230.1260, figure 9.

      C.  The basic qualification test positions are, as follows:

        (1) pipe, horizontal rolled; weld, flat position.  Pipe with its axis in the horizontal plane and rolled during welding so that the weld metal is deposited from the top and within ± 15 degrees from the vertical plane;

        (2) pipe, vertical fixed; weld, horizontal position.  Pipe with its axis in the vertical position and the weld with its axis in the horizontal plane;

        (3) pipe, horizontal fixed; weld, flat, vertical, and overhead positions.  Pipe with its axis in the horizontal
plane and the welding groove in the vertical plane.  Welding shall be done without rotating the pipe so that weld metal is deposited from the flat, vertical, and overhead positions.

      D.  Qualification in test position covered in item C, subitem (1) qualifies for that position only.  Test positions
covered in item C, subitem (2) or (3) shall qualify for the respective test positions and also for test position covered in
item C, subitem (1). 

    Qualification in test position covered in both item C, subitems (2) and (3) are required for qualification in all weld
positions, regardless of orientation of weld or pipe axis.

      E.  In cases when production welding is to be done in one particular position outside of that defined in item C,
subitem (1) both procedure and welder qualification may be made for that position, with the limitation that procedure and welder qualification shall be varied only for the actual special position tested.  An angular tolerance of ± 10 degrees shall apply.

    Subp. 6.  Types of test specimens.  Test specimens for making qualification tests are two types; reduced-section
tension specimens and guided-bend specimens.  The reduced-section tension test is used to determine the tensile
strength of the weld joint in procedure qualification tests.  The dimensions and preparation of the test specimen shall
conform to the requirements.  The alternative 0.505 in. specimen may be used for material three-fourths inch and over in thickness.  The guided-bend test is used to check for degree of soundness and ductility of the weld in both procedure and performance qualification tests.  Guided-bend test specimens are of three kinds, as follows:

      A.  Side-bend test specimens that conform to the requirements shall be used in making guided-bend tests of welds
that are over three-fourths inch in thickness and may be used in making guided-bend tests of welds that are over three-eighths inch in thickness. 

      B.  Face-bend and root-bend test specimens that conform to the requirements shall be used in making guided-bend
tests of welds that are 1/16 inch to three-eighths inch in thickness and may be used in making guided-bend tests of welds that are up to three-fourths inch in thickness.  The face bend specimen shall be bent with the face of the weld in tension, and the root bend specimen shall be bent with the root of the weld in tension.

    Subp. 7.  Reduced section tension tests.  The reduced-section tension test specimens shall be ruptured under
tensile load.  The tensile strength shall be computed by dividing the maximum load by the product of the least width and corresponding thickness of the specimen as measured before load is applied.

    The reduced-section tension test specimen shall have a tensile strength that is not less than the minimum of the
specified tensile strength of the base material or of the weaker of the two if materials of different specified minimum tensile strengths are used.  If the specimen breaks in the base metal outside of the weld or fusion line, the test shall be accepted as meeting the requirements provided the strength is not more than five percent below the specified minimum tensile strength of the base metal.

    Subp. 8.  Guided-bend test.  Side-bend, face-bend, and root-bend specimens shall be bent in a test-jig that has been
approved by the Division of Pipefitting Standards.  The specimen shall be placed on the die of the test-jig with the weld at mid-span.  The side of the specimen turned toward the gap of the jig shall be the face for face-bend specimens, the root for root-bend specimens, and the side with the greater defects, if any, for side-bend specimens.  The specimen shall be forced into the die by applying load on the plunger until the curvature of the specimen is such that a 1/32 inch diameter wire cannot be inserted between the die and the specimen.

    Guided-bend specimens shall have no cracks or other open defects exceeding one-eighth inch measured in any direction on the convex surface of specimen after bending except that cracks occurring on the corners of the specimen during testing shall not be considered, unless there is definite evidence that they result from slag inclusions or other internal defects.

    STAT AUTH: MS s 326.46
HIST: 14 SR 1877; 17 SR 1279
Current as of 04/07/05
5230.0260 SCOPE.

Power Piping Systems

    "Power piping systems" shall be understood to include all steam piping and the component parts such as pipe, flanges, bolting, gaskets, valves, and fittings, within or forming a part of the above-mentioned plants, including central and district heating steam or hot water distribution piping away from the plant, building heating piping when the pressure exceeds 15 psi gage for steam, or 30 psi gage for hot water and a temperature exceeding 250 degrees Fahrenheit, whether the piping is installed underground or elsewhere.

    Valves, fittings, and piping for boilers, as prescribed in the ASME Code for Power Boilers, are within the scope for this code but provisions of the ASME Code for Power Boilers shall govern where they exceed corresponding requirements of this code.

    Economizers, heaters, tanks, and other pressure vessels are outside the scope of this code, but connecting piping shall conform to the requirements herein specified.

    STAT AUTH: MS s 326.46
Current as of 04/07/05

Ammonia Refrigeration


    Parts 5230.5000 to 5230.6200 form the code for ammonia refrigeration systems and applies to ammonia piping systems used for closed circuit refrigeration systems.  Parts 5230.5000 to 5230.6200 are minimum standards and are not intended to be used as or considered as a system design manual except as otherwise specified.  If a system has any component designed for temperatures below minus 20 degrees Fahrenheit (minus 28.9 degrees centigrade), then the entire system, including components, must meet the test requirements of the American Society of Mechanical Engineers, American National Standards Institute, B31.5 refrigerating systems for operating at temperatures below minus 20 degrees Fahrenheit (minus 28.9 degrees centigrade).

    STAT AUTH: MS s 326.46
HIST: 17 SR 438
Current as of 04/07/05
 More information can be found at http://www.doli.state.mn.us/hpp.html

Custom welding is no problem.  We can weld on the job site or in our fabrication shop.

Look to Leading Edge Mechanical for all of your custom welding needs.

Home || About Us || Contact/Find Us || Affiliations || Plumbing || HVAC || Refrigeration || Boiler Service || Process Piping || Fabrication || Welding || Site Map