Risk-Based Alternative
This Appendix provides guidance on how a risk-based alternative to pressure testing older hazardous liquid and carbon dioxide pipelines rule allowed by § 195.303 will work. This risk-based alternative establishes test priorities for older pipelines, not previously pressure tested, based on the inherent risk of a given pipeline segment. The first step is to determine the classification based on the type of pipe or on the pipeline segment's proximity to populated or environmentally sensitive area. Secondly, the classifications must be adjusted based on the pipeline failure history, product transported, and the release volume potential.
Tables 2-6 give definitions of risk classification A, B, and C facilities. For the purposes of this rule, pipeline segments containing high risk electric resistance-welded pipe (ERW pipe) and lapwelded pipe manufactured prior to 1970 and considered a risk classification C or B facility shall be treated as the top priority for testing because of the higher risk associated with the susceptibility of this pipe to longitudinal seam failures.
In all cases, operators shall annually, at intervals not to exceed 15 months, review their facilities to reassess the classification and shall take appropriate action within two years or operate the pipeline system at a lower pressure. Pipeline failures, changes in the characteristics of the pipeline route, or changes in service should all trigger a reassessment of the originally classification.
Table 1 explains different levels of test requirements depending on the inherent risk of a given pipeline segment. The overall risk classification is determined based on the type of pipe involved, the facility's location, the product transported, the relative volume of flow and pipeline failure history as determined from Tables 2-6.
Table 1. Test Requirements—Mainline Segments Outside of Terminals, Stations, and Tank Farms
Pipeline segment
| Risk classification
| Test deadline
1
| Test medium
|
---|
Pre-1970 Pipeline Segments susceptible to longitudinal seam failures
2 | C or B
A | 12/7/2000
3
12/7/2002
3 | Water only.
Water only.
|
All Other Pipeline Segments | C | 12/7/2002
4 | Water only.
|
| B | 12/7/2004
4 | Water/Liq.
5
|
| A | Additional pressure testing not required.
| |
Using LOCATION, PRODUCT, VOLUME, and FAILURE HISTORY “Indicators” from Tables 3, 4, 5, and 6 respectively, the overall risk classification of a given pipeline or pipeline segment can be established from Table 2. The LOCATION Indicator is the primary factor which determines overall risk, with the PRODUCT, VOLUME, and PROBABILITY OF FAILURE Indicators used to adjust to a higher or lower overall risk classification per the following table.
Table 2—Risk Classification
Risk classification
| Hazard location indicator
| Product/volume indicator
| Probability of failure indicator
|
---|
A | L or M | L/L | L.
|
B | Not A or C Risk Classification
|
C | H | Any | Any.
|
Table 3 is used to establish the LOCATION Indicator used in Table 2. Based on the population and environment characteristics associated with a pipeline facility's location, a LOCATION Indicator of H, M or L is selected.
Table 3—Location Indicators—Pipeline Segments
Indicator
| Population
1
| Environment
2
|
---|
H | Non-rural areas | Environmentally sensitive
2 areas.
|
M | | |
L | Rural areas | Not environmentally sensitive
2 areas.
|
Tables 4, 5 and 6 are used to establish the PRODUCT, VOLUME, and PROBABILITY OF FAILURE Indicators respectively, in Table 2. The PRODUCT Indicator is selected from Table 4 as H, M, or L based on the acute and chronic hazards associated with the product transported. The VOLUME Indicator is selected from Table 5 as H, M, or L based on the nominal diameter of the pipeline. The Probability of Failure Indicator is selected from Table 6.
Table 4—Product Indicators
Indicator
| Considerations
| Product examples
|
---|
H | (Highly volatile and flammable) | (Propane, butane, Natural Gas Liquid (NGL), ammonia)
|
| Highly toxic | (Benzene, high Hydrogen Sulfide content crude oils).
|
M | Flammable—flashpoint <100F | (Gasoline, JP4, low flashpoint crude oils).
|
L | Non-flammable—flashpoint 100 + F | (Diesel, fuel oil, kerosene, JP5, most crude oils).
|
| Highly volatile and non-flammable/non-toxic | Carbon Dioxide. |
Considerations: The degree of acute and chronic toxicity to humans, wildlife, and aquatic life; reactivity; and, volatility, flammability, and water solubility determine the Product Indicator. Comprehensive Environmental Response, Compensation and Liability Act Reportable Quantity values can be used as an indication of chronic toxicity. National Fire Protection Association health factors can be used for rating acute hazards.
Table 5—Volume Indicators
Indicator
| Line size
|
---|
H | ≥18″.
|
M | 10″-16″ nominal diameters.
|
L | ≤8″ nominal diameter.
|
Table 6 is used to establish the PROBABILITY OF FAILURE Indicator used in Table 2. The “Probability of Failure” Indicator is selected from Table 6 as H or L.
Table 6—Probability of Failure Indicators
[in each haz. location]
Indicator
| Failure history (time-dependent defects)
2
|
---|
H
1 | >Three spills in last 10 years.
|
L | ≤Three spills in last 10 years.
|
[Amdt. 195-65, 63 FR 59480, Nov. 4, 1998; 64 FR 6815, Feb. 11, 1999]