Current through Register 1531, September 27, 2024
Notwithstanding any provision of the MFS Standards which may
allow less stringent requirements, the following additional rules or
modifications shall apply.
(1)
Low-pressure Distribution System. (Section 192.3 MFS
Standards.) For the purpose of 220 CMR 101.06, a low-pressure distribution
system shall be defined as any system in which the gas pressure in the main is
equal to or less than two pounds per square inch gauge (psig).
(2)
Intermediate-pressure
Distribution System. (Section 192.3 MFS Standards.) For the
purpose of 220 CMR 101.06, an intermediate pressure distribution system shall
be defined as any system in which the gas pressure in the main is greater than
two psig, but equal to or less than 60 psig.
(3)
High-pressure Distribution
System. (Section 192.3 MFS Standards.) For the purpose of 220 CMR
101.06, a high-pressure distribution system shall be defined as a system in
which the pressure in the main is greater than 60 psig, but equal to or less
than 200 psig.
(4)
Class Locations. (Section 192.5 MFS Standards.) For
the purpose of
220 CMR 101.00, every gas
piping system shall be designed, constructed, tested, operated, and maintained
using a class 3 location as a minimum class location designation.
(5)
Design Limitations for
Plastic Pipe. (Section 192.123 MFS Standards.)
(a) The wall thickness for thermoplastic pipe
may not be less than 0.090 inches.
(b) The Department may approve the use of
reinforced thermosetting plastic pipe having a wall thickness not less than
that listed in the following table:
|
Normal Size in Inches
|
Minimum Wall Thickness in Inches
|
|
2
|
0.060
|
|
3
|
0.060
|
|
4
|
0.070
|
|
6
|
0.100
|
(6)
Distribution Line
Valves. (Section 192.181 MFS Standards.) Each high-pressure and
intermediate pressure distribution system must have valves spaced so as to
reduce the time to shut down a section of main in an emergency. The valve
spacing is determined by the operating pressure, the size of mains, and the
local physical conditions.
(7)
Control of the Pressure of Gas Delivered from High-pressure
Distribution Systems. (Section 192.197 MFS Standards.) For the
purpose of
220 CMR 101.00, §
192.197 of the MFS Standards shall be entitled: Control of the Pressure
of Gas Delivered from Mains Operating at Higher Pressures than the Pressure
Provided to the Customer .
(8)
Required Capacity of Pressure
Relieving and Limiting Stations. (Section 192.201 MFS Standards.)
Relief valves or other pressure limiting devices must be installed at or near
each regular station controlling the pressure to a system operating at a
pressure that is substantially the same as the pressure provided to the
customer, with a capacity to limit the maximum pressure in the main to a
pressure that will not exceed the safe operating pressure for any connected and
properly adjusted gas utilization equipment.
(9)
Inspection and Test of
Welds. (Section 192.241 MFS Standards.)
(a) Notwithstanding the requirements of 220
CMR 101.06(9)(b), not less than 10% of the welds randomly sampled over the
length of at least three of the installations of which notice of construction
is required under
220 CMR
101.04 shall be radiographically examined and
available to the Department. If less than three installation projects are
undertaken by any company, at least 10% of the welds shall be radiographically
examined and available to the Department.
(b) The Department may, at any time, visually
inspect any welding and if it is considered faulty, order the operating company
to subject the weld to a destructive test as outlined in MFS Standards,
Appendix C, paragraph I or to a radiographic examination.
(10)
Protection from
Hazards. (Section 192.317 MFS Standards.)
(a) The method of protecting all new piping
on trestles and bridges shall be subject to the approval of the Department. For
each such bridge crossing, the operator shall submit a written request for
approval and a detailed installation plan to the Department that includes the
following items:
1. The proposed nominal pipe
diameter, wall thickness, (minimum wall thickness 0.237"), and the Specified
Minimum Yield Strength (SMYS).
2.
For nominal pipe diameters 12" or greater, a calculation of the hoop stress (H)
in accordance with the following formula:
Click to view
image
H = Hoop stress in pounds per square inch
P = Maximum Operating Pressure in pounds per square inch
gauge
D = The specified outer diameter in inches
t = Specified wall thickness in inches (not less than
0.237").
3. Method of
providing for expansion or contraction of the bridge, if necessary.
4. Pipe support details, number of supports,
and distances between supports.
5.
The plan shall indicate that valves are provided on both sides of the bridge
and their approximate location.
(b) For bridges under the care and control of
the Massachusetts Department of Transportation (MassDOT), the procedure for a
MassDOT permit shall be as follows:
1. On new
bridges, a preliminary design plan will be submitted by MassDOT to the
pertinent utility company notifying it of the proposed construction and
suggested location of pipe on or in the bridge structure. (A copy of this
letter will be forwarded to the Director of the Pipeline Safety Division of the
Department).
2. The utility company
will submit a plan to the Department within 30 days of the receipt of the afore
described design plan if any construction is proposed on the particular
bridge.
3. No permit for the
installation of gas facilities on bridges will be considered, unless MassDOT
has received from the Department a letter approving the design.
4. All requests for permits for gas
facilities on new bridges shall be directed to the Highway and Structures
Engineer at the Highway Division of MassDOT.
5. All requests for new gas facilities on
existing bridges shall be directed to the Maintenance Engineer at the Highway
Division of MassDOT.
(12)
Cover. (Section 192.327 MFS Standards.)
(a) Except as provided in 220 CMR
101.06(12)(c) each buried transmission line must be installed with a minimum
cover as follows:
|
TABLE 1 |
|
Location
|
Normal Soil Inches
|
Consolidated Rock Inches
|
|
Class 3 and 4 locations
|
36
|
24
|
|
Drainage and ditches of public roads and railroad
crossings
|
36
|
24
|
(b)
Gas mains to be installed in highways under the jurisdiction and control of the
MassDOT shall be laid with a minimum cover of 36 inches from the top of the
main to the used surface of the road.
(c) Except as provided in 220 CMR
101.06(12)(d) and (e), each buried main must be installed with at least 24
inches of cover.
(d) Where an
underground structure prevents the installation of a transmission line or main
with the minimum cover, the transmission line or main may be installed with
less cover if it is provided with additional protection to withstand
anticipated external loads.
(e) A
main may be installed with less than 24 inches of cover providing:
1. Adequate measures are taken to prevent
damage to the pipe by external forces.
2. That the maximum allowable operating
pressure will produce a stress level of less than 20% of SMYS.
3. That the Department approves the
installation.
(13)
Service Lines: Valve
Requirements. (Section 192.363 MFS Standards.) Each service line
valve on an intermediate-pressure or high-pressure service line installed above
ground or in an area where the blowing of gas would be hazardous, must be
designed and constructed to minimize the possibility of the removal of the core
of the valve with other than specialized tools.
(14)
Service Lines: Location of
Valves. (Section 192.365 MFS Standards.) All intermediate-and
high-pressure services and all services two inches in diameter or larger shall
be equipped with an underground curb shut off located in proximity to the
property line, except that whenever gas is supplied to a theatre, church,
school, factory, or other buildings where large numbers of persons assemble, an
outside shut off in such case will be required regardless of the size of the
service or of the service pressure. All underground curb shut offs shall be
readily identifiable and available for easy access by gas company
personnel.
(15)
Test
Requirements for Pipelines to Operate at a Hoop Stress Less than 30% of SMYS
and above 100 psig. (Section 192.507 MFS Standards.) Except for
service lines and plastic pipelines, each segment of a pipeline that is to be
operated at a hoop stress less than 30% of SMYS and above 100 psig must be
tested in accordance with the following:
(a)
The pipeline operator must use a test procedure that will ensure discovery of
all potentially hazardous leaks in the segment being tested. However, loss of
pressure due to leakage during the test period is not permitted.
(b) If, during the test, the segment is to be
stressed to 20% or more of SMYS and natural gas, inert gas, or air is the test
medium:
1. A leak test must be made at a
pressure between 100 psig and the pressure required to produce a hoop stress of
20% of SMYS; or
2. The line must be
walked to check for leaks while the hoop stress is held at approximately 20% of
SMYS.
(c) Steel gas
mains to be operated at pressures from 100 psig to 150 psig shall be air or
hydrostatically tested for tightness to 1.5 times the maximum allowable
operating pressure for at least one hour.
(d) Steel gas mains to be operated at
pressures in excess of 150 psig shall be air or hydrostatically tested for
tightness to 1.5 times the maximum operating pressure for at least four hours
and may be witnessed by the Department. Calibrated recording instruments shall
be verified by dead weight instruments and the recording submitted to the
Department for certification that the steel gas main as defined may be operated
at a pressure which is equal to the test pressure divided by a factor of
1.5.
(16)
Test Requirements for Pipelines to Operate at or below 100
psig. (Section 192.509 MFS Standards.) Except for service lines
and plastic pipelines, each segment of a pipeline that is to be operated at or
below 100 psig must be leak tested in accordance with the following:
(a) The pipeline operator must use a test
procedure that will ensure discovery of all potentially hazardous leaks in the
segment being tested. However, loss of pressure due to leakage during the test
period is not permitted.
(b) At a
test pressure of at least 90 psig for at least one hour.
(c) The tie-in joints to the live gas main,
cast iron or steel, shall be tested using the soap bubble test.
(17)
Test Requirements
for Service Lines. (Section 192.511 MFS Standards.)
(a) Each segment of a service line (other
than plastic) must be leak tested in accordance with 220 CMR 101.06 before
being placed in service. If feasible, the service line connection to the main
must be included in the test. If not feasible, it must be given a leakage test
at the operating pressure when placed in service.
(b) Each segment of a service line (other
than plastic) to operate at not more than 100 psig shall be tested after
construction and before being placed into service to at least 90 psig for not
less than 15 minutes. Pressure loss due to leakage during the test period is
not permitted.
(c) Each segment of
a service line (other than plastic) to operate at pressures in excess of 100
psig must be tested in accordance with
49
CFR 192.507 of the MFS Standards.
(18)
Test Requirements
for Plastic Mains and Services. (Section 192.513 MFS Standards.)
(a) The test procedure must ensure discovery
of all potentially hazardous leaks in the segment being tested. However, loss
of pressure due to leakage during the test period is not permitted.
(b) The test pressure shall be at least 150%
of the maximum operating pressure or 90 psig whichever is the greater, for at
least 15 minutes for services, or one hour for mains. However, the maximum test
pressure may not be more than three times the design pressure of the
pipe.
(19)
Maximum Allowable Operating Pressure: Intermediate-pressure and
High-pressure Distribution Systems. (Section 192.621 MFS
Standards.) No person may operate a segment of an intermediate-pressure or
high-pressure distribution system at a pressure that exceeds the lowest of the
applicable pressures shown in
49
CFR 192.621(a)(1) through (5) and
(b) of the MFS Standards.
(20)
Odorization of
Gas. (Section 192.625 MFS Standards.)
(a) A combustible gas in a distribution line
shall have a distinctive odor of sufficient intensity so that a concentration
of 0.15% gas in the air is readily perceptible to the normal or average
olfactory senses of a person coming from fresh uncontaminated air into a closed
room containing one part of the gas in 666 parts of air.
(b) In the concentrations in which it is
used, the odorant in combustible gases must comply with the following:
1. The odorant may not be deleterious to
persons, material, or pipe.
2. The
products of combustion from the odorant may not be toxic when breathed nor may
they be corrosive or harmful to those materials to which the products of
combustion will be exposed.
(c) The odorant may not be soluble in water
to an extent greater than 2.5 parts to 100 parts by weight.
(d) Equipment for odorization must introduce
the odorant without wide variations in the level of odorant.
(e) Equipment and facilities for handling the
odorant shall be located so as to minimize the effect of an escape of
odorant.
(f) Each operator shall
conduct periodic samplings of the combustible gases to assure the proper
concentration of odorant in accordance with 220 CMR 101.06.
(21)
Distribution
Systems: Leakage Surveys and Procedures. (Section 192.723 MFS
Standards.) Each operator having a gas distribution system shall conduct
leakage surveys, as frequently as experience and technology indicates they are
necessary, but in no event shall such leakage surveys be less than the
following minimum standards:
(a)
Business Districts. A gas detector survey must be
conducted in business districts including tests of the atmosphere in gas,
electric, telephone, sewer and water system manholes, at cracks in pavement and
sidewalks, and at other locations providing an opportunity for finding gas
leaks, at least once in every consecutive 12-month period. In areas where an
effectively prescribed and supervised survey of electric or other manholes and
vaults is conducted and offers more frequent coverage than the previous, such a
survey procedure may be substituted. Business districts are defined as areas
with pavement from building wall to building wall and/or where the principal
commercial activity of the city or town takes place. Such areas shall be
outlined on a map and maintained by the operator.
(b)
Distribution System Areas Not
Included in the Principal Business District. Leakage surveys shall
be made of the area not included in the principal business district at least
once in every consecutive 24-month period.
(c)
Type of Survey.
Leakage surveys for 220 CMR 101.06(21)(a) and (b) shall include one or more of
the following:
1. Gas detector surveys using
combustible gas indicators, flame ionization equipment, infra-red equipment or
other industry accepted testing equipment;
2. Bar tests;
3. Vegetation surveys; and
4. Pressure drop tests.
(d)
Other Surveys.
In addition to the requirements of 220 CMR 101.06(21)(a) and (b), a survey of
schools, churches, hospitals, theatres, and arenas shall be conducted at least
once annually. The survey shall include tests for gas leakage and visual
inspection of gas facilities in the immediate area of the service
entrance.
(e)
Hazardous
Conditions Repaired. All disclosed conditions of a nature
hazardous to persons or property shall be promptly made safe and permanent
repairs instituted.
(f)
Leakage Survey Records. Records of the leakage surveys
required under 220 CMR 101.06 shall be maintained for a period of time not less
than the interim between successive surveys.
(22)
Test Requirements for
Reinstating Service Lines. (Section 192.725 MFS Standards.)
(a) For the purpose of 220 CMR 101.06(22),
each service line, temporarily disconnected from the main and to be operated at
a pressure not in excess of one psig, shall be tested at a pressure of at least
ten psig for not less than 15 minutes. Pressure loss due to leakage during the
test period is not permitted.
(b)
The operator shall make and retain a record of each pressure test required
under
49 CFR
192.725 MFS Standards.
