Current through Register Vol. 49, No. 13, September 23, 2024
Subpart 1.
Casing types.
If casing is used in a temporarily sealed exploratory boring,
the casing must be:
A. steel casing as
specified in subpart 15;
B.
stainless steel casing as specified in subpart 16; or
C. plastic casing as specified in subparts 17
and 18.
Subp. 2.
Watertight casing required.
All casing must be watertight throughout its length, with
threaded, solvent welded, or welded joints. Recessed couplings, reamed and
drifted couplings, integral flush-threads, or other couplings that match the
design, taper, and thread type of the casing must be used on threaded casing.
Thread must not be exposed on the exterior of the pipe when the casing is
joined to the coupling or when the pipe sections are joined together.
Subp. 3.
New casing
required.
Casing installed in a temporarily sealed exploratory boring
must be new casing produced to specifications. Casing removed from an
exploratory boring is acceptable for reuse in an exploratory boring if the
casing meets the specifications for new casing.
Subp. 4.
Casing markings
required.
Casing must be marked by the manufacturer according to casing
specifications in subparts 15 to 18. Markings must be rolled, stamped, or
stenciled by the manufacturer.
Subp.
5.
Casing testing.
Casing rejected by the manufacturer must not be used. The
commissioner may require that casing be submitted to an independent testing
agency to evaluate whether it meets or exceeds specifications when the
casing:
A. lacks markings or has
illegible or altered markings;
B.
contains pits, cracks, patches, partial welds, bends, or other manufacturing
defects; or
C. lacks mill
certification papers from the original manufacturer.
Subp. 6.
Casing rejection.
The commissioner shall reject casing if:
A. the casing is not submitted for evaluation
and verification when required by the commissioner;
B. the casing fails to meet the
specifications in subparts 15 to 18; or
C. the lot of casing contains defective
lengths, including casing with girth-welded joints or casing with welded
patches.
Subp. 7.
Removed casing.
Casing that is installed during drilling, sometimes referred
to as surface casing, and that is removed upon completion of drilling is not
required to meet the specifications for casing in subparts 15 to 18, but must
be of sufficient strength to withstand the structural load imposed by
conditions both inside and outside the exploratory boring.
Subp. 8.
Outer casing; unconsolidated
materials.
An outer casing installed in unconsolidated materials is not
required to meet the specifications for casing in subparts 15 to 18 if:
A. the casing is of sufficient strength to
withstand the structural load imposed by conditions both inside and outside the
boring;
B. an inner casing meeting
the requirements of subpart 1 is installed; and
C. the annular space between the casings is
filled with neat cement grout.
Subp.
9.
Inner and outer casing.
The annular space between an inner casing and an outer casing
must be grouted for its entire length by pumping neat cement grout through a
tremie pipe, a drill rod, or the casing as specified in part 4727.0980.
Subp. 10.
Casing
height.
All casings of a temporarily sealed exploratory boring must
extend vertically at least one foot above the established ground surface and at
least five feet above the regional flood level. The established ground surface
immediately adjacent to the casing must be graded to divert water away from the
casing. Termination of the top of the casing below the established ground
surface, such as in a vault or pit, is prohibited.
Subp. 11.
Casing offsets.
Casing offsets are prohibited.
Subp. 12.
Minimum casing depth.
An exploratory boring that is temporarily sealed must be
cased according to items A to C. Borings that flow must meet the special
requirements in part 4727.0985.
A. A
boring that terminates in unconsolidated materials must be cased from a point
one foot above the established ground surface and at least five feet above the
regional flood level to the bottom of the boring.
B. A boring that terminates in igneous or
metamorphic bedrock must be cased from a point one foot above the established
ground surface and at least five feet above the regional flood level into
igneous or metamorphic bedrock.
C.
A boring that terminates in sedimentary bedrock must be cased from a point of
one foot above the established ground surface and at least five feet above the
regional flood level into sedimentary bedrock. When a confining layer is
encountered, the boring must be cased according to part 4727.0975.
Subp. 13.
Casing
cover.
The casing of a temporarily sealed exploratory boring must be
covered with a water tight and insect-proof cap or cover equivalent to the
casing in weight and strength consisting of:
A. an overlapping cap with compression
gasket; or
B. a threaded or welded
cover or cap.
Subp. 14.
Casing protection.
The casing of an exploratory boring that is temporarily
sealed must be protected by at least one of the following methods:
A. surrounding the casing with a concrete
pyramid or cone that has horizontal dimensions of at least 24 inches by 24
inches at the established ground surface, rises 12 inches above the established
ground surface at the casing, and has a base with a volume of at least three
cubic feet below the established ground surface;
B. installing a steel outer protective casing
meeting the specifications of subpart 15 that is at least 3.25 inches in
diameter larger than the inner casing, extends at least two feet above the
established ground surface and four feet below the established ground surface,
and has neat cement grout or concrete grout in the annular space between the
casings from the bottom of the outer protective casing to the established
ground surface;
C. placing three
posts at least four inches square or four inches in diameter around the boring
at equal distances from each other and two feet from the exploratory boring.
The posts must extend two feet above the established ground surface and four
feet below the established ground surface, or to a depth of two feet if each
post is set in concrete to a depth of two feet. The posts must be made of
reinforced concrete, decay-resistant wood, or steel pipe meeting the
specifications of subpart 15. Steel pipe must be covered with an overlapping,
threaded, or welded steel or iron cap or be filled with concrete or cement;
or
D. extending the casing
vertically at least four feet above the established ground surface and
reporting the accurate location of the exploratory boring on the temporary
sealing report. The location must be determined and reported by using either a
differential global positioning system or a survey with bearings and distances
taken from property corners or a permanent survey control point.
Subp. 15.
Steel casing
requirements.
A. Steel casing used in
the construction of a temporarily sealed exploratory boring must be produced to
the following specifications:
(1) ASTM
Standard A53-90b;
(2) ASTM Standard
A589-89a, Types I, II, and III;
(3)
API Specification 5L;
(4) DCDMA
Technical Manual, section B designations C80, R80, or RC100, and section D
flush joint casing standards; or
(5) CSA Standard M253.1 - M1981 for flush
joint casing.
B. Steel
casing must have the minimum weights and thicknesses specified in this item,
subject to the tolerance in the specifications in item A.
|
Size in Inches |
Plain End |
Wgt. Lbs. Per Ft. Thrds. & Cplgs.* |
Thrds. R&D Cplgs. |
Thickness in Inches |
| S |
1 |
1.68 |
1.68 |
1.70 |
.133 |
| c |
1-1/4 |
2.27 |
2.28 |
2.30 |
.140 |
| h |
1-1/2 |
2.72 |
2.73 |
2.75 |
.145 |
| e |
2 |
3.65 |
3.68 |
3.75 |
.154 |
| d |
2-1/2 |
5.79 |
5.82 |
5.90 |
.203 |
| u |
3 |
7.58 |
7.62 |
7.70 |
.216 |
| l |
3-1/2 |
9.11 |
9.20 |
9.25 |
.226 |
| e |
4 |
10.79 |
10.89 |
11.00 |
.237 |
|
5 |
14.62 |
14.81 |
15.00 |
.258 |
| 4 |
6 |
18.97 |
19.18 |
19.45 |
.280 |
| 0 |
8 |
28.55 |
29.35 |
|
.322 |
|
10 |
40.48 |
41.85 |
|
.365 |
| S |
12 |
49.56 |
51.15 |
|
.375 |
| t |
14 |
54.57 |
57.00 |
|
.375 |
| a |
16 |
62.58 |
65.30 |
|
.375 |
| n |
18 |
70.59 |
73.00 |
|
.375 |
| d |
20 |
78.60 |
81.00 |
|
.375 |
| a |
22 |
86.61 |
|
|
.375 |
| r |
24 |
94.62 |
|
|
.375 |
| d |
26 |
102.63 |
|
|
.375 |
|
30 |
118.65 |
|
|
.375 |
| W |
32 |
126.66 |
|
|
.375 |
| g |
34 |
134.67 |
|
|
.375 |
| t |
36 |
142.68 |
|
|
.375 |
* Nominal weight based on length of 20 feet including
coupling.
Steel casing up to ten inches in diameter must be Schedule
40. Larger diameter casing must be standard weight.
| Diameter-Inches |
Couplings |
| External |
Internal |
Thrds. per Inch |
Minimum External Diameter Inches |
Minimum Length Inches |
| 1.315 |
1.049 |
11-1/2 |
1.576 |
2-5/8 |
| 1.660 |
1.380 |
11-1/2 |
1.900 |
2-3/4 |
| 1.900 |
1.610 |
11-1/2 |
2.200 |
2-3/4 |
| 2.375 |
2.067 |
11-1/2 |
2.750 |
2-7/8 |
| 2.875 |
2.469 |
8 |
3.250 |
3-15/16 |
| 3.500 |
3.068 |
8 |
4.000 |
4-1/16 |
| 4.000 |
3.548 |
8 |
4.625 |
4-3/16 |
| 4.500 |
4.026 |
8 |
5.200 |
4-5/16 |
| 5.563 |
5.047 |
8 |
6.296 |
4-1/2 |
| 6.625 |
6.065 |
8 |
7.390 |
4-11/16 |
| 8.625 |
7.981 |
8 |
9.625 |
5-1/16 |
| 10.750 |
10.020 |
8 |
11.750 |
5-9/16 |
| 12.750 |
12.000 |
8 |
14.000 |
5-15/16 |
| 14.000 |
13.250 |
8 |
15.000 |
6-3/8 |
| 16.000 |
15.250 |
8 |
17.000 |
6-3/4 |
| 18.000 |
17.250 |
8 |
19.000 |
7-1/8 |
| 20.000 |
19.250 |
8 |
21.000 |
7-5/8 |
| 22.000 |
21.250 |
|
|
|
| 24.000 |
23.250 |
|
|
|
| 26.000 |
25.250 |
|
|
|
| 30.000 |
29.250 |
|
|
|
| 32.000 |
31.250 |
|
|
|
| 34.000 |
33.250 |
|
|
|
| 36.000 |
35.250 |
|
|
|
Subp.
16.
Stainless steel casing requirements.
Stainless steel casing used in the construction of a
temporarily sealed exploratory boring must meet ASTM Standard A312-86a and meet
at least:
A. ANSI Schedule 5 for
welded joints; and
B. ANSI Schedule
40 for threaded joints.
Subp.
17.
Plastic casing requirements.
Plastic casing and couplings used in the construction of a
temporarily sealed exploratory boring must:
A. meet ASTM Standard F480-88;
B. withstand internal pressures of 200 pounds
per square inch (psi); and
C. have
a minimum standard dimension ratio (SDR) of 21.
Subp. 18.
Additional approved plastic
couplings.
In addition to plastic couplings approved under subpart 17,
couplings meeting the following requirements are also approved:
A. couplings with socket dimensions meeting
the requirements of ASTM Standard F480-88, Table 3; and
B. ANSI Schedule 40, four-inch and five-inch
diameter slip x female thread and five-inch diameter slip x male thread
couplings meeting the requirements of ASTM Standard D2466-90a.
Subp. 19.
NSF standard for
plastic material.
All plastic casings, couplings, components, and related
joining materials, including solvents, cements, or primers, used in the
construction of a temporarily sealed exploratory boring must conform with the
requirements of NSF Standard 61-1991 or the health effects portion of NSF
Standard 14-1990 and be tested as conforming by an agency certified by ANSI.
Conformance to the NSF standard must be coded, stamped, or marked on the
casings, couplings, and components, as well as on the containers of related
joining materials, including solvents, cements, or primers.
Subp. 20.
Plastic casing
installation.
A. When preparing to
install plastic casing, a person must:
(1)
inspect casing and couplings carefully for cuts, gouges, deep scratches,
damaged ends, and other major imperfections. Any plastic casing or coupling
having such defects or imperfections shall not be used;
(2) use solvent cement meeting the
requirements of the specifications for the plastic that will be used;
(3) use only casing and coupling combinations
that give interference fits; and
(4) use plastic couplings with molded or
formed threads and thread lubricants suitable for the plastic material that
will be used.
B. When
cutting plastic casing, casing ends must be cut square using fine-tooth blades
with little or no set or a plastic pipe cutter equipped with extra wide rollers
and thin cutting wheels. Standard steel pipe or tubing cutters must not be used
for cutting plastic casing.
C. All
dirt, dust, and moisture must be cleaned from casing ends and couplings using
chemical or mechanical cleaners suitable for the particular plastic material.
All burrs must be removed from casing ends and couplings.
D. A primer must be used when required or
recommended by the solvent cement label instructions.
E. An even coat of solvent cement must be
applied to the inside of the couplings to cover the distance of the joining
surface only. An even coat of solvent cement must then be applied to the
outside of the casing being joined to a distance equal to the depth of the
casing coupling socket.
F. When
assembling plastic casing, a person must:
(1)
make the joint with solvent cement before the solvent cement dries;
(2) reapply cement before assembling if the
solvent cement dries partially;
(3)
turn the casing to evenly distribute the solvent cement while inserting the
coupling into the coupling socket;
(4) insert the casing to the full depth of
the coupling socket and assemble casing;
(5) remove excess solvent cement from the
exterior of the joint with a clean, dry cloth;
(6) tighten a threaded joint by no more than
one full turn using a strap wrench;
(7) not disturb the coupling joint until
after the solvent cement has set; and
(8) allow sufficient time for the solvent
cemented joint to set.
G. Screws must not be used to join plastic
casing.
H. A person must not drill
inside plastic casing. Drilling tools such as drill bits must not be inserted
in plastic casing.
I. Plastic
casing must not be used as an outside casing in exploratory borings cased more
than five feet into limestone or dolomite bedrock. In limestone or dolomite
bedrock, plastic casing may be used as an inner casing if surrounded by an
outer steel casing.
J. Plastic
casing must not be driven.
K. A
person installing plastic casing must either seal the exploratory boring or
remove and replace all casing when:
(1) the
plastic casing cannot be installed without driving the casing; or
(2) the casing fails during
construction.
Statutory Authority: MS s
103I.101
