Pipeline Valve Spacing - Comparison of Codes

TABLE D1. PIPELINE VALVE SPACING AND DESIGN REQUIREMENTS IN GAS TRANSMISSION PIPELINE CODES No.

Pipeline Code 1 US B31.8-1995 Edition

Code Approach

Valve Spacing Basis

Design is based on a class Building Density/ location concept with valve class location. spacing, and allowable stress levels based on the class location.

Valve spacing Reqts......

Valve Closure Reqts....

Location Class Definition

Class 1. Para. 846.11, "the Class 2. Para.846.11, "the Class 3. Para.846.11, "the Class 4. Para.846.11, "the 846.21(d) This code does 1. 840.2a.1, 10 or fewer buildings intended for spacing between valves on spacing between valves on spacing between valves on spacing between valves on not require the use of a new transmission line a new transmission line a new transmission line a new transmission line automatic valves, nor does human occupancy in a the Code imply that the use zone 220 yds. on each shall not exceed 20 mi. in shall not exceed 15 mi. in shall not exceed 10 mi. in shall not exceed 5 mi. in side of the pipeline and 1 of automatic valves Location Class 1." Location Class 2. Location Class 3 ." Location Class 4" mile in length which presently developed will provide full protection to a encompasses the maximum number of piping system. buildings (cont.)

2. 840.2a2, 11 or <46 buildings intended for human occupancy in a zone 220 yds.. on each side of the pipeline and 1 mile in length which encompasses the maximum number of buildings. (cont.)

3. 840.2a3 >46 buildings intended for human occupancy in a zone 220 yds. on each side of the pipeline and 1 mile in length which encompasses the maximum number of buildings (cont.)

Consideration shall be given to the consequences of a failure near a concentration of people, such as found in a church, school, multiple dwelling unit, hospital, or recreational area in Location Class 1 or 2.

Pipelines near places or public assembly or concentrations of people such as churches , schools, multiple dwelling unit buildings, hospitals, or recreational areas of an organized nature in Location Class 1 or 2 shall meet requirements forLocation Class3

Also, consider future development possibilities

Also, consider future development possibilities

Also, consider future development Also, consider future possibilities development possibilities

0.39 persons/10,000 sq. yds (0.46 persons/ha)

0.43 to 17.8 persons/10,000 Greater than 1.78 persons/10,000 sq. yds (0.51 to 21.3 persons/ sq. yds (Greater than ha) 2.13 persons/ha)

Class 1. Waste lands, deserts, rugged mountains, grazing land, and farm land. (A) the 10 mile density index for any section of the line is 12 or less. (B) the 1 mile density index for any section of the line is 20 or less.

Class 2. Development is intermediate between Class 1 and Class 3 locations. (A) the 10 mile density index exceeds 12 or (B) the 1 mile density index exceeds 20.

Their use and installation Consideration shall be shall be at the discretion of given to the consequences the operating company. of a failure near a concentration of people, such as found in a church, school, multiple dwelling unit, hospital, or recreational area in Location Class 1 or 2.

UNIFORM CLASS LOCATION BASIS

HISTORICAL DATA

2 US 49CFR Part 192

1955-1968 CODES

Based on ASME B31.8. Building Density Design rules are based on a class location concept. The class location concept was modified from that in the B31.8 Code in 1968 to a specific number of houses in a 1/4 mile width, one mile long with only one density index .

Class 1, 20 mile spacing




192.179(4) Each point on a pipeline in a Class 1 location must be within 10 miles of a sectionalizing block valve.

192.179 (3) Each point on a pipeline in a Class 2 location must be within 7.5 miles of a sectionalizing block valve.

192.179 (2) Each point on a pipeline in a Class 3 location must be within 4 miles of a sectionalizing block valve.

Finally able get point on here. 192.179 (1) to Each on a pipeline in a Class 4 location must be within 2.5 miles of a sectionalizing block valve.

192.179(b)(1)The valve 1. 192.5(b), 10 or less and the operating device to buildings intended for open or close the valve human occupancy. must be readily accessible and protected from tampering and damage.

Class 3. Subdivided areas for residential or commercial purposes and 10% of the lots abutting on the street or right-ofway are built upon at the time of construction.

2. 192.5(c), more than 10 but 3. 192.5(d),1) 46 or more buildings less than 46 or more buildings intended for human occupancy, or intended for human occupancy 2) an area where the pipeline lies within 100 yds of either a building or a small, well-defined outside area (such as a play ground, recreation area, outdoor theater, (cont.)

or other place of public assembly) that is occupied by 20 or more persons at least 5 days a week or for 10 weeks in any 12-month period.



When a cluster of buildings intended for human occupancy requires a Class 2 location, the Class 2 location ends 220 yds from the nearest building in the cluster.

When a cluster of buildings intended for human occupancy requires a Class 3 location, the Class 3 location ends 220 yds from the nearest building in the cluster.

Greater than 0.39 to 1.78 persons/10,000 sq. yds (Greater than 0.46 to 2.13 persons/ ha)

Greater than 1.78 persons/10,000 sq. yds (Greater than 2.13 persons/ha)

Class location concept was changed to a one-quarter mile width and one mile long zone in which the houses were counted. Specific house counts were defined for the four class locations.

HISTORICAL DATA-1968

So sorry you have dented

D1

4. 840.2a4, Multistory (>4 stories) buildings are present and heavy traffic in a zone 220 yds. on each side of the pipeline and 1 mile in length which encompasses the maximum number of buildings.

Class 4. Multistory buildings are prevalent and where traffic is heavy or dense and where there may be numerous other utilities underground.

4. 192.5(e), A Class 4 Location is any class location unit where buildings with four or more stories aboveground are prevalent.


Pipeline Code 3 Canadian Z662-94, Oil and Gas Pipeline Systems Note, a revision is due out in 1997 but the areas of interest herein have not changed.

Code Approach Based on ASME B31.8 . Specified design rules based on a class location concept.

Valve Spacing Basis 4.4.3, Valves shall be located upstream and downstream of any pipeline segment at a spacing not greater than the applicable value given in Table 4.6 Table 4.6 shown in valve spacing reqts... columns

Valve spacing Reqts...... Table 4.6 as follows: For gas pipelines in Class 1 Location, valves are not required.

Table 4.6 as follows: For gas pipelines in Class 2 Location, 25 km (15.6 miles) valve spacing.


Table 4.6 as follows: Class Table 4.6 as follows: Class There are no requirements 3 Location, 13 km (8.1 4 Location, 8 km (5miles) for valve closure operators miles) valve spacing. valve spacing. on gas pipelines. Sour gas lines specifically do not require the use of automatic valves however, automatic closing devices shall be considered.

Location Class Definition 1. 4.3.2.2. Class location areas that contain 10 or fewer dwelling units intended for human occupancy shall be designated Class 1 locations.

2. 4.3.2.3.1 Class location areas that contain more than 10 but fewer than 46 dwelling units intended for human occupancy shall be designated Class 2 locations.

3. 4.3.2.4.1 Class location areas that contain more than 46 dwelling units intended for human occupancy shall be designated Class 3 locations.

4. 4.3.2.5 class locations areas where buildings intended for human occupancy with 4 or more stories above ground are prevalent shall be designated Class 4 locations.

4.3.2.3.2 Class location areas that contain the following shall be designated Class 2 locations (a) a building that is occupied by 20 or more persons during normal use; (cont.)

4.3.2.4.2 Consideration shall be given to designation class location areas that contain institutions where rapid evacuation may be difficult, such as hospitals or nursing homes, as Class 3 locations.

4.3.2.6.1 The end boundaries for Class 4 location shall be not less than 200m (219 yds) , measured parallel to the pipeline axis, from the nearest building intended for human occupancy with 4 or more stories above ground.

(b) a small, well-defined outside area that is occupied by 20 or more persons during normal use such as a playground, recreation area, outdoor theater, or other place of public assembly; or

4.3.2.6.2 Where clusters of dwelling units intended for human occupancy require Class 2 or 3 location designations, the end boundaries fore such Class 2 or 3 locations shall be not less than 200 m (219 yds) measured parallel to the pipeline axis, (cont.)

(c) an industrial installation such as a chemical plant or hazardous substance storage area, where release of products from a pipeline could cause the industrial installation to produce a dangerous or environmentally hazardous condition.

the nearest dwelling unit in the cluster.

4.3.2.6.3 Where Class 2 location designations result from the application of the requirements of Clause 4.3.2.3.2, the end boundaries for such Class 2 locations shall be not less than 200 m ( 219 yds), measured parallel to the pipeline axis, (cont.)

4 Australian SAA AS 2885-1987 Based on a class location Class Location concept where the classes are based on individual size and not number of houses, similar in some respects to IGE TD/1.

Table 3.4, Location Class R1, as required

Table 3.4, Location Class R2, 30 km. max. (18.8 mi.)

Table 3.4, Location Class T1 and T2, 15 km. max. (9.4 mi.)

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from the nearest building, place of public assembly, or industrial installation, whichever is applicable. Greater than 0.39 to 1.78 Greater than 1.78 persons/10,000 persons/10,000 sq. yds (>0.46 sq. yds ( Greater than 2.13 to 2.13 persons/ ha) persons/ha)



Valves shall be installed so that in the event of a leak the valves can be expeditiously operated. Where necessary, mainline valves shall be remotely operable.

3.5.2.2 R1 - Broad Rural. A location in an undeveloped area or a broadly farmed area that is sparsely populated where, typically, the area of the average allotment is greater than 5 ha.

3.5.2.3 R2- Semi Rural. A location in a rural area developed for small farms or rural area developed for small farms or rural residential use. where, typically, the area of the average allotment is between 1 ha and 5 ha.

3.5.2.4 T1 - Suburban. A location in an area developed for residential, commercial, or industrial use where the majority of buildings have less than four floors and where, typically, the area of the average allotment is less than 1 ha.


Class R1, 0.5 persons/ 10000 sq. yds (0.6 persons / ha)

Class R2, 0.5 to 2.5 persons/ 10000 sq. yds (0.6 to 3.0 persons / ha)

Class T1, > 2.5 persons/ 10000 sq. yds (>3.0 persons / ha)

3.5.2.5 T2 - High Rise. A location in an area developed for residential, commercial, or industrial use where the majority of building have four or more floors and where, typically, the area of the average allotment is less than 1 ha.


Pipeline Code

Code Approach

Valve Spacing Basis


5 UK Pipelines Safety Regulations 1996

A risk based approach that requires that the lines be designed, operated and maintained so that the risk to the public is acceptable.

No specified spacing requirements. Emergency shutdown valves are required.

Sched. 3 requires emergency shut-down valves to be normally closed valves, be capable of being closed, be able to pass equipment for inspecting and testing, be protected from damage arising from fire, explosion or impact and be maintained .

6 Institute of Gas Engineers TD/1 Edition 3, 93

Design basis based on class location concept defined on the basis of number of persons / unit area.

Judgment and operational considerations

6.13.1 In a cross-country pipeline, valves should be provided at periodic intervals and may be handoperated, automatic or remotely controlled.



Schedule 3, 3. An No class locations defined. emergency shut down valve shall also be capable of being closed; (a) by a person positioned by it; and (b) automatically by the operation of the emergency shut-down system of the offshore installation to which the pipeline is connected.

6.13.1 In built-up areas, the spacing of valves should be reduced. In determining the spacing of valves, consideration should also be given to operating pressure, pipeline diameter, time taken to arrive at the valve site, (cont.)

6.13.1. Valves may be hand operated, automatic or remotely controlled.

6.8.1 Type R. Rural areas with a population density not exceeding 2.5 persons per hectare.

6.8.1 Type S. Areas intermediate in character between Types R and T in which the population density exceeds 2.5 persons per hectare and which may be extensively developed with residential properties, schools, shops, etc.


< 2.1 persons/ 10,000 sq. yds (2.5 persons / ha)

>2.1 persons/ 10,000 sq. yds (>2.5 persons /ha )

probability of leakage, the need for valves for operational purposes, the position of the nearest offtakes and other existing valves. 6.13.2 The valves should be installed in readily accessible positions.

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6.8.1 Type T. Central areas of towns or cities, with a high population density, many multistory buildings, dense traffic and numerous underground services.


Pipeline Code

7 ISO 13623, Draft 9/7/96

8 NEN 3650 (Netherlands)

9 SNIP 2.05.06-85 Russian Pipeline Code

Code Approach

Valve Spacing Basis



Design is based on a class 6.11 Place where location concept. required for operation, maintenance, and control of emergencies

No specific requirements.

6.11 The mode of operation of section isolation valves shall be established when determining their location.

Annex B. Class 1. No perm. human habitation, deserts, and tundra..


Zero persons/ ha or sq. yd. Less than 0.42 persons/ From 0.42 to 2.1 persons/10,000 Greater than 2.1 persons/ 10,000 sq. yd ( 0.5 persons/ha sq. yd. (0.5 to2.5 persons / ha ) 10,000sq yd (2.5 ) persons/ha )

6.4.4. Valves must be quick-acting but automatic or remote control of the valves is not a requirement but may be conducive to effect limitation; and easily accessible from the public road for operation, maintenance and inspection.

Location Class 1. other premises, scattered residential housing or no residential housing. Residential buildings; buildings intended for permanent occupation including apartment buildings, buildings of 3 or more stories, residential areas, (cont.)

Code specifies two design Prescriptive approaches; 1) a risk approach is tied to approach that assures that location class each transport pipeline is designed, constructed and operated such that the additional risk to the surrounding area is acceptable, i.e., <10-6, or 2) simplified analysis.

6.4.4. 30 km in location class 1 and the volume of gas enclosed between any two valves at design pressure must be less than 700,000 "normal"(a) cu. meters.

The approach normally implemented is the simplified analysis procedure or prescriptive codes rules contained in it.

(a) one "normal" cu. meter of gas occupies 1 cu. meter at a pressure of 1013.25 moar at a temperature of 0 C.

The code breaks pipelines No specific down into Classes and requirements Categories. The gas presented pipeline classes are 1 (pressure > 2.5- 10 MPa (363-1450 psi) and 2 (pressure >1.2 - 2.5 MPa (174-363 psi). In addition, there are 5 Categories, B, I, II, III, IV (cont.)

6.4.4. 20 km in location class 2 and the volume of gas enclosed between any two valves at design pressure must be less than 700,000 "normal" cu. meters.




Annex B. Class 2. < 50 persons/ square km. Wasteland, grazing land, farm land, and sparsely pop. areas

Location class 2. Sports halls and indoor swimming pools, supermarkets, hotels or office buildings not covered by Category I, industrial buildings such as factories or workshops, not covered by category I, underground storage tanks, parks, woods (cont.)

Annex. B. Class 3. 50 to 250 persons/square km., with multiple dwelling units, with a hotel or office building with less than 50 perm. persons.

Location class 3. (Table A1.1) Residential areas, recreational areas or industrial areas. Residential areas; groups of adjacent dwellings where the shortest distance between the dwellings does not generally exceed 10 m.

and scattered and golf courses where several development detached people may be present for dwellings dispersed over a short periods. wide area or ribbon development at right angles to the transport pipeline.

Not more than 30 km (18.6 mi) apart. They are to be on both sides of water obstacles crossed by pipelines that No mention of valve closure Category B, Piping in are crossed by two or more lines. requirements. compressor stations, gas regulating stations, inside compressor buildings,

The gas design categories are a function of : gas versus oil, diameter and pressure; buried, on ground, or above ground; road crossings, railroad crossings, river crossings; distances to valves, compressor stations and gas treatment plants, (cont.)

Category I, river crossings, floodplains, (>00 mm dia) railroad crossings, major auto roads, adjacent to gas storage station, pig launchers, suction and discharge piping in compressor stations, crossing buried lines, and under hi voltage (500kv) lines.

Design requirements are specified for buried piping, piping in a tunnel continuously supported and in stations. No class locations are defined

Category II, flood plains (< 700 mm, 27 inch dia..), adjacent to railroad and road crossings, mud stream crossings, 250 m on either side of block valves, gathering lines between fields, crossing other pipelines, under hi voltage lines (cont.)

(300 to 500 kv), in erosive areas, and laid in an industrial corridor (meter station, gas reducing/regulating, booster compressor stations, ).

6.5 Pipelines should be sectionalized using valves which may be of manual, automatic or remote controlled operation.

No specific valve spacing requirements

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Location class 4. (Table A1.1) Apartment building or residential homes for the elderly and nursing homes, including hospitals and sanitarium, school and shopping centers, hotel or office buildings accommodation more than 50 people, (cont.) building of considerable infrastructure value, such as computer centers, telephone exchanges , airtraffic control equipment, and buildings which presumes an increased risk due to secondary effects, such as aboveground storage tanks, etc.

and stability of the ground. 10 Euro Norm p EN 1594 (CEN/TC 234)

Annex B. Class 4, 250 or more persons/square km., such as suburban housing developments, residential areas, industrial areas and other areas not meeting class 5.

No Class Locations are defined.

Category III, below, on or above ground pipelines, local road crossings, in mountainous areas, in desert sands, within 100 m (328 ft) of a connection to a Category II section, and crossing big and small ravines.


Pipeline Code

Code Approach

Valve Spacing Basis



German Standard 463 , Par.. 3.2.2 , indicates that the distance between two main shut-off devices is determined by the local conditions and requirements for supply; a distance of 10 to 18 km (6 to 11.3 mi) is generally adequate.

No Requirements


This is a code that has minimum requirements for gas pipelines. If it is more stringent than a countries code it would apply (European countries.) It is weighted on the maintenance and operation of pipelines. Applies to pipelines operated at >16 bar. 11 German DIN 2470, 2413, and Construction Code 463

Bases design on the elongation properties of the steel. No class locations are included.

Based on Class Locations Based on Class 12 Algerian Pipeline Code which are defined on the Locations Safety Regulations Concerning Transportation' basis of population Pipelines of Combustible Gas

Article 31, Spacing between two gate valves in Zones 1 and 1a will not exceed 10 Km (6.1 mi.). In urban areas, the volume of gas measured under normal conditions, between two successive valves shall not exceed 90,000 cu. meters.

Article 31, Spacing between two gate valves in Zones 2 and 3 will not exceed 20 km (12.2 mi.). In urban areas, the volume of gas measured under normal conditions, between two successive valves shall not exceed 90,000 cu. meters.

Code does not use class locations. Population density or proximity to houses or buildings is not a consideration.

Article 31. Gate valves or Zone 3, sites located in other system allowing to desert regions rapidly limit or stop the flow, eventually automatically or by remote command must be installed at regular interval on the pipes.

Zone 2, sites located in rural zones, farming and cultivated fields, forests, and close to agglomerations.

Zone 1a, located at least 75 m Zone 1, urban zones with from public buildings or a national high population density. defense installation; density per hectare is >10 based on the population in a 200 m along the line and 100 m distance on either side of line; located in the national public area.

Density 10 persons/ha.

13 French Pipeline Design Code Based on Class Locations Based on three which are defined on the Class Locations basis of population Information is based on verbal information obtained from Gas de France. 14 Regulations Concerning Transportation of Petroleum in Onshore Pipelines, 1986Norway Directorate for Fire and Explosion Prevention

Based on the Canadian Z 183 and Z 184.

Class Location

None

Class 1, less than 16 people

Class 2, greater than 16 and less than 160 people

Class 3, greater than 160 people

All class locations have a requirement for the gas volume between valves to be 90,000 cu. meters or less.


Less than 3.4 persons/10,000 sq yds (4 persons/ha)

3.4 to 34 persons/10,000 sq yds ( 4 to 40 persons/ ha)

Greater than 34 persons/10,000 sq yds (40 persons/ha)

32 km (20 mi) in Class 1

None

22. Up to 5 dwellings

22. 6 to 30 dwellings

22. More than 30 dwellings or 22. Any route unit where locations which contain 20 or more there is one or several people. buildings with 4 or more storeis above ground.


0.32 persons/ 10,000 sq yds (0.38 persons/ha)

0.38 to 1.91persons/ 10,000 sq yds (0.45 to 2.25 persons/ha)

More than 1.91persons/ 10,000 sq yds (more than 2.25 persons/ha)

20 km in Class 1

20 km in Class 2


10 km in Class 3

12 km (7.5 mi) in Class 3


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Location Class Definition No.

Pipeline Code

Pipeline Corridor for Class Location

1 US B31.8-1995 Edition

220 yds (200 m) on either side of the pipeline

Retroactive Application? Yes, with regard to the design stress (Class Location change). No, with regard to valve spacing.

Discussion

Design Basis

846.21c Spacing may be adjusted slightly to permit a valve to be installed in a more accessible location, with continuous accessibility being the primary consideration.

Building Density (population density) with the design factors based on nominal wall thickness and outside diameter.

846.21d, Automatic valve closures are not required.

Design Stress Levels in Location Class, % SMYS Class 1, Div. 1, 0.80 design factor for new construction, per table 841.114A; Div. 2, 0.72 design factor, per Table 841.114A for new construction (Div. 2.) for all API 5L pipe except furnace butt welded. 0.43 design factor for furnace (contd) butt weld pipe. 0.60 design factor for (1) crossing of unimproved public roads, roads, highways, or public streets with hard surfaces, and railroads without casings and (2) parallel encroachment of pipelines and mains on roads, (cont.)

Class 2, 0.60 design factor, per Table 841.114A for all API 5L pipe except furnace butt weld pipe. 0.35 design factor for furnace butt weld pipe.

Class 3. 0.50 design factor, per Table 841.114A for all API 5L pipe except furnace butt weld pipe. 0.30 design factor for furnace butt weld pipe.

Class 4. 0.40 design factor, per Table 841.114A for all API 5L pipe except furnace butt weld pipe. 0.20 design factor for furnace butt weld pipe.

0.50 design factor crossings of roads, highways, or public streets with hard rd surfaces with railroads without casings.

highways or public street with hard surfaces and railroads. Also at fabricated assemblies and pipelines on bridges.

One mile density index, count the number of buildings in a zone one-half mile on each side of the pipeline and one mile long. The 10 mile density index is the sum of the one mile density indexes for any 10 mile length of line.

2 US 49CFR Part 192

220 yds (200 m) on either side of the pipeline

Yes, per Par... 192.609 and 192.611. with regard to design factor. No with regard to valve spacing.

0.72 design factor for all other road and railroad crossings.

0.60 design factor for all other road and railroad crossings.

0.50 design factor for all 0.40 design factor for all road and railroad road and railroad crossings. crossings.

0.50 design factor for compressor station piping and near concentration of people.



0.40 design factor for compressor station piping and near by concentrations of people.

Class location is the basis for design.

Class 1, 0.72 design factor



Class 4. 0.40 design factor

Building Density with the design factors based on nominal wall thickness and outside diameter.

Class 1, 0.72 design factor, Par. 192.111. 0.60 design factor or less for steel pipe in Class 1 locations that: (1) Crosses the right-ofway of an unimproved public road, with a casing; (cont.)

Class 2. 0.60 design Class 3. 0.50 design factor, Par. 192.111. factor, Par. 192.111. 0.50 design factor, or less for uncased steel pipe that crosses the right-of-way of a hard surfaced road, a highway, a public street, or a railway.

(2) Crosses without a casing, or makes a parallel encroachment on, the right-of-way of either a hard surfaced road, a highway, a public street , or a railroad; (cont.)

0.50 design factor for steel pipe in a compressor station, regulating station, or measuring station; and steel pipe, including a pipe riser, on a platform located offshore or in inland navigable waters.

(3) Is supported by a vehicular, pedestrian, railroad, or pipeline bridge; or (4) Is used in a fabricated assembly, or is used within five pipe diameters in any direction from the last fitting of (cont.) a fabricated assembly, other than a transition piece or an elbow used in place of a pipe bend which is not associated with a fabricated assembly. 0.50 design factor for steel pipe in a compressor station, regulating station, or measuring station; and steel pipe, including a pipe riser, on a platform located offshore or in inland navigable waters.

D6

Class 4. 0.40 design factor, Par. 192.111.


Pipeline Code

3 Canadian Z662-94, Oil and Gas Pipeline Systems Note, a revision is due out in 1997 but the areas of interest herein have not changed.


Retroactive Application?

Discussion

Class Location areas shall extend 200 m (220 yds.) on both sides of the centerline of any continuous 1.6 km (1 mi.) length of pipeline except as defined at the ends.

Yes, Par. 10.7.1. indicates that where class locations change as a result of changes in population density or location development, an engineering assessment shall be made to determine if the pipeline is satisfactory for the changed class location.

4.4.4 It shall be permissible to adjust the valve spacing and location specified in Clause 4.4.3 based on factors such as operational, maintenance, access, and system design considerations. Note: Valve spacing adjustments should not (cont.)

Design Basis

Design Stress Levels in Location Class, % SMYS

Population Density using a Class Location factor, a proximity factor and a design factor of 0.8. Wall thickness is the design wall thickness and the diameter is the outside diameter of the pipe. (cont.)

Class 1, Table 4.1, General and cased crossings have an allowable stress of 0.8 (1.00*0.8) SMYS. Roads and Other* have an allowable stress of 0.6 (0.75*0.8) SMYS. Railways and stations have an allowable stress of 0.5 (0.625*0.8) SMYS.

Class 2. Table 4.1, General and cased crossings have an allowable stress of 0.72 (0.90*0.8) SMYS. Roads, railways and stations have an allowable stress of 0.5 (0.625*0.8) SMYS. Others have an allowable stress of 0.6 (0.75*0.8) SMYS.

Class 3. Table 4.1, General and cased crossings have an allowable stress of 0.56 (0.7*0.8) SMYS. Roads, railways, stations, and Other* have an allowable stress of 0.5 (0.625*0.8) SMYS.

Class 4. Table 4.1, General and cased crossings have an allowable stress of 0.44 (0.55*0.8) SMYS. Roads, railways, stations, and Other* have an allowable stress of 0.4 (0.5*0.8) SMYS.

exceed 25 % of the Nominal wall thickness *Other: Piping that is (a) supported by a vehicular, pedestrian, railway, or pipeline bridge; (b) used in a fabricated applicable distances listed in equals the design thickness assembly; or © with five pipe diameters in any direction of a fabricated assembly, other than a transition piece or Table 4.6. plus the corrosion an elbow used(contd) allowance, plus the threading and groove allowances. Nominal wall cannot be less than the design wall thickness. Outside diameter of the pipe and the SMYS are used 4.4.9 For gas pipeline systems, blowdown valves shall be located so that the sections of transmission lines between sectionalizing valves can be blown down. Sizes and capacities of the connections for blowing down transmission lines shall be (cont.)

in place of a pipe bend that is not asssociated with a fabricated assembly.

such that, under emergency conditions, the section can be blown down as rapidly as practicable. Locations of blowdown valves shall be such that the gas can be blown to the atmosphere without undue hazard.

4 Australian SAA AS 2885-1987

There is no specific definition of Corridor width for determining Location Types. Par. 3.5.2.9 states" Where a point on a pipeline in a Class R1 location or a Class R2 location is within 100 m of a location where the average daily congregation is (cont.)

more than 20 people, the pipeline shall be considered to be in a Class t1 location for a distance of 100 m in both directions from that point. It appears that 100 m is the corridor width.

3.5.2.8 Yes at intervals not exceeding 5 years, and where necessary, appropriate corrective action shall be taken.

Concentration of the population without specific building density requirements. Outside diameter is used with the nominal wall thickness which cannot be less than 10 mm (0.393 inch) where wall thickness and depth of cover provide third party protection.

3.6 & 3.7 Class R1. Design factor is 0.72 with a third-party damage factor of 1 results in a design factor of 0.72. (Applies to the SMYS of a published specification unless the actual yield strength is determined by field test.) Min. w.t.=10 mm (3.7.2.2)

3.1.5.2 Required wall thickness cannot be less than pressure design thickness (PD/2sigma y) plus manufacturing under tolerance if greater than 12.5%, plus corrosion, threading and machining tolerance.

D7

3.6 &3.7 Class R2. Design factor is 0.72 with a third-party damage factor of 1.2 results in a design factor of 0.6 (Applies to the SMYS of a published specification unless the actual yield strength is determined by field test.) Min w.t.= 10 mm (3.7.2.2)

3.6 & 3.7 Class T1. Design factor is 0.72 with a third-party damage factor of 1.44 results in a design factor of 0.5 (Applies to the SMYS of a published specification unless the actual yield strength is determined by field test.) Min w.t.=10mm (3.7.2.2)

3.6 & 3.7 Class T2. Design factor is 0.72 with a third-party damage factor of 1.8 results in a design factor of 0.4 (Applies to the SMYS of a published specification unless the actual yield strength is determined by field test.) Min. w.t.=10 mm (3.7.2.2)


Pipeline Code

5 UK Pipelines Safety Regulations 1996

Pipeline Corridor for Class Location Not applicable

Retroactive Application? Yes, requires that modification, maintenance or other work on a pipeline is carried out in such a way that its soundness and fitness for the purpose for which it has been designed will not be prejudiced.

Discussion

Design Basis


Reg. 5, that a pipeline shall No specific requirements other be designed to withstand than that it suitable for the the expected strains and intended usage. processes. Reg. 8, that a pipeline be constructed of suitable materials. Reg. 9, that it be constructed and installed that it is sound and fit for its purpose.

Reg. 11, that the safe operating limits of a pipeline be established and not exceeded, save for testing. Reg. 12 that adequate arrangements be made for dealing with incidents and emergencies involving a pipeline. 6 Institute of Gas Engineers TD/1 Edition 3, 93

6.8.2 Population density, expressed as the number of persons per unit hectare, should be the average for each 1.6 km (1 mi.) of pipeline in a strip centered on the pipeline of a width 8 times the minimum building proximity distance (BPD) for a (cont.) Type R area pipeline as defined in Figure 2. (Figure 2 presents BPD that range from 10 to 110 m. For 508 mm (20 inch) diameter lines at 66.7 bar (1000 psi), the BPD ranges from 50 to 90 m.

1) Min. wall; 2) Outside diameter of pipe, 3) Population density; 4) Fatigue cycles and 5) specified minimum yield stress.

6.8.4.1 Design factor should not exceed 0.72 and design pressure should not exceed 100 bar (1500 psi). (cont.)

6.8.5.1 Design factor should not exceed 0.30 and design press. should not exceed 100 bar (1500 psi). Design factors greater than 0.3 may be, BPD in Table 3 may be justified by a risk analysis carried out as partof a pipeline safety evaluation . (cont.)

6.8.4.2 If wall thickness exceeds 19.1 mm (0.75 inch) then 19.1 mm will suffice provided the design factor is less than 0.5. Also, if risk analysis justifies it, the BPD from Table 3 S Type areas, may be used (Appendix 3 provides guidelines.)

6.8.5.2 If wall thickness exceeds 19.1 mm (0.75 inch) then 19.1 mm will suffice provided the design factor is less than 0.5. Also, if risk analysis justifies it, the BPD from Table 3 S Type areas, may be used (Appendix 3 provides guidelines.)

6.8.4.2 When design factor is less than 0.3, BPD in Table 3 may be used, other wise Table 2 values.

6.8.5.2 Proximity of pipelines to normally occupied buildings should be related to maximum operating pressure per Figure 3. Pipelines of nom. wall thickness <9.52 mm (0.375 in.) can use Curve B Figure 3 if additional protection is installed.

TRAFFIC: 6.11.1 Pipelines which either cross, or encroach with, the appropriate proximity distance of a high density traffic route, should have a nom. wall thickness of not less than 11.91 mm (0.469-in). The design factor should not exceed 0.30. (cont.) However, when this calls for pipe with a nom. wall thickness of 19.1 mm (0.75 in) , the 19.1 mm pipe is acceptable, provided that it does not result in the design factor exceeding 0.5. A higher design factor may be justified by risk analysis. 6.11.2 Pipelines crossing or running within the boundary of other traffic routes should have a nom. wall thickness of not less than 9.52 mm (0.375-in) or should have impact protection. The design factor should not exceed 0.30. (cont.)

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6.8.6 Pipelines should be constructed per IGE/TD/3 Distribution lines.


Pipeline Code



Discussion

Design Basis

Design Stress Levels in Location Class, % SMYS However, when this calls for pipe with a nom. wall thickness of 19.1 mm (0.75 in) , the 19.1 mm pipe is acceptable, provided that it does not result in the design factor exceeding 0.5. A higher design factor may be justified by risk analysis.

7 ISO 13623, Draft 9/7/96

Annex B. Class 5, multistory buildings, traffic is heavy or dense, and numerous underground utilities.

400 m (440 yds) in width centered on the pipeline and for a sliding length of 1.5 km (0.94 mi).

Outside diameter minus t min., t min, and P int. - P ext., Sigma y is SMYS at max. design temp.

Class 1. 0.83

Class 2. 0.77

Class 3. 0.64

Class 4. 0.55

A1.2 The corridor width is based on a "critical distance" on either side of the pipeline. The length is also taken as the "critical distance". The critical distance is a function of the diameter and operating pressure. (cont.)

Design factor based on location class and whether it is in a pipeline corridor. The design factors are; 1.39 (0.72), 1.50 (.67), and 1.82 (.55) applied to the hoop stress based on average diameter (D-t) and t min. The allowable stress is the SMYS.

Location class 1. In designated pipeline corridors, DF = 1.39 (0.72) for mechanical damage protection. Other pipelines, DF = 1.39 (0.72).

Location class 2. In designated pipeline corridors, DF (design factor) = 1.39 (0.72) for mechanical damage protection. Other pipelines, DF = 1.50 (.67).

Location class 3. In designated pipeline corridors, DF = 1.50 (0.67) for mechanical damage protection. Other pipelines, DF =1.82 (.55).

Location class 4. In designated pipeline corridors, DF = 1.50 (0.67) for mechanical damage protection. Other pipelines, DF = 2.22 (.45)

Class 5. 0.44

Same as US, Can. Class 4. 8 NEN 3650 (Netherlands)

For dia... of 8 in (200 mm), the critical distance is 4, 5, and 5 m for 20-50, 50-80. and 80-110 bar pressures respectively. For 30 in (750 mm) dia..., the critical distance is 30 and 35 m for 50-80 and 80-110 bar pressures respectively. (Table A2-1)

There is also a minimum wall thickness for all location classes which is a function of the pipe diameter. For example, 219.1 mm (8 inch) dia.., min wall is 4.5 mm (.177 in), for 508 mm (20 in) , the min wall is 5.6 mm (.220 in), (cont.)

and for 914 mm (36 in), 6.4 mm ((.251 in). There are also design requirements for various roads, road crossings, canal crossings and pipelines on airports. In addition, there are design requirements for the various loading experienced by the pipeline.

9 SNIP 2.05.06-85 Russian Pipeline Code

10 Euro Norm p EN 1594 (CEN/TC 234)

Category IV, below Grd. lines < 1200 mm (47.2 in) in dia..,

None defined since class location does not include a width on the sides of the pipeline.

Unknown

Allowable stresses outside of a pipeline corridor.

Location class 1. Outside designated pipeline corridors, Max. Allowable stress =0.72 SMYS or ).72 x 0.75 SMUS, which ever is lower.

The specified minimum ultimate stress is the basis. This is modified by the type of pipe and the location category of the pipe as well as the load factor (how well the load is known, i.e., seismic/soil movement loads versus pressure loads).

Category B, m=0.60, specifies Category I & II, m=0.75 code specifies allowable Category III & IV, m=0.90 code specifies allow. allowable stress as 0.43 SMUS stress as 0.53 SMUS (for welded steel pipe with a stress as 0.64 SMUS (for welded steel pipe with a (for welded steel pipe with a 0.85 Y/U is 0.63 SMYS. However, they have a load 0.85 Y/U 0.75 SMYS. However, they have a load 0.85 Y/U, this equals 0.50 factor that ranges from 1.0 to 1.15. Thus, the allow. factor that ranges from 1.0 to 1.15. Thus, the SMYS. However, they have a stress could be between 0.63 and 0.55 SMYS.) allow. stress could be between 0.75 and 0.65 load factor that ranges from 1.0 SMYS.) to 1.15. Thus, the allow. stress could be between 0.50 and 0.44 SMYS.)

Maximum stress is 0.72 SMYS based on OD and min wall thickness for buried piping and piping continuously supported in a tunnel. In a station, the maximum stress is 0.67 SMYS.

D9

Location class 2. Outside designated pipeline corridors, Max. Allowable stress = 0.65 SMYS or 0.65 x 0.75 SMUS, which ever is lower.




Pipeline Code



Discussion

Design Basis


This is a code that has minimum requirements for gas pipelines. If it is more stringent than a countries code it would apply (European countries.) It is weighted on the maintenance and operation of pipelines. Applies to pipelines operated at >16 bar. 11 German DIN 2470, 2413, and Construction Code 463

Not applicable

No

DIN 2470 defines allowable stress levels based on steel yield strength.

12 Algerian Pipeline Code Safety Regulations Concerning Transportation' Pipelines of Combustible Gas

200 m along the line, +/100 m perpendicular to the line.

Code does not appear to be retroactively applied when zones change.

Thickness is based on the min. wall, OD. The allowable stress is limited to a percent of the yield stress and or the ultimate stress.

Design factors are: Grd B-X42, 0.66; X46, 0.65; X52, 0.64; X60 & above 0.625 SMYS

Zone 3, 80 % minimum yield stress (SMYS), or 60 % of the ultimate stress (SMUS-specified minimum ultimate stress). Based on t, which is nom. t minus the under thickness tolerance and the outside diameter.


Zone 1a, 60 % minimum yield stress (SMYS), or 36 % of the ultimate stress (SMUSspecified minimum ultimate stress). Based on t, which is nom. t minus the under thickness tolerance and the outside diameter.


A second requirement is that the maximum operating pressure cannot exceed .85 times the mill test pressure which must be at least 90 % of the SMYP

A second requirement is that the maximum operating pressure cannot exceed 0.83 times the mill test pressure which must be at least 90 % of the SMYP



A brief review indicated that with API pipe grades from X52 to X70, the ultimate strength requirement controls reducing the stress by factors of 0.95 to 0.68 of what would be possible if the yield stress were used for the design. 13 French Pipeline Design Code

200 m along the line, 100 m Code does not appear to perpendicular to the line. be retroactively applied when zones change.

Class Location, however, information on use of min. wall and average dia. was not available.

Class 1, 0.73 SMYS

Class 2, 0.60 SMYS

Class 3, 0.40 SMYS

A route unit is determined continuously along a pipeline and is an area 1000 m along the line, 200 m on either side of the line.

Class location

Class 1, 0.72

Class 2, 0.60

Class 3, 0.50

Information is based on verbal information obtained from Gas de France. 14 Regulations Concerning Transportation of Petroleum in Onshore Pipelines, 1986Norway Directorate for Fire and Explosion Prevention

Class 1 and 2 locations are to be survey annually. Class 3 and 4 locations are to be surveyed every 6 months.

Class 4, 0.40

Design is based on nominal wall thickness, nominal diameter, and SMYS.

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Pipeline Valve Spacing - Comparison of Codes

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