In the Federal Register of September 15, 2003, RSPA published a final rule concerning the operation and capacity of existing pressure limiting and regulating stations on gas pipelines. The rule inadvertently established a pressure limit that could require a reduction in the operating pressure of some pipelines and be impracticable for others to meet. This direct final rule establishes an appropriate pressure limit to avoid these unintended results.
The following are the modified rules issued by OPS:
§ 192.739 Pressure limiting and regulating stations: Inspection and testing.
(a)(3) Except as provided in paragraph (b) of this section, set to control or relieve at the correct pressure consistent with the pressure limits of § 192.201(a); and
(b) For steel pipelines whose MAOP is determined under § 192.619(c), if the MAOP is 60 psi (414 kPa) gage or more, the control or relief pressure limit is as follows:
| If the MAOP produces a hoop stress that is: | Then the pressure limit is: |
|---|---|
| Greater than 72 percent of SMYS | MAOP plus 4 percent. |
| Unknown as a percentage of SMYS | A pressure that will prevent unsafe operation of the pipeline considering its operating and maintenance history and MAOP. |
§ 192.743 Pressure limiting and regulating stations: Capacity of relief devices.
(a) Pressure relief devices at pressure limiting stations and pressure regulating stations must have sufficient capacity to protect the facilities to which they are connected. Except as provided in § 192.739(b), the capacity must be consistent with the pressure limits of § 192.201(a). This capacity must be determined at intervals not exceeding 15 months, but at least once each calendar year, by testing the devices in place or by review and calculations.
The complete Federal Register Notice can be downloaded from RCP’s website here through the DOT Gateway.
For more information, contact L.M. Furrow by phone at 202-366-4559, by fax at 202-366-4566, by mail at U.S. Department of Transportation, 400 Seventh Street, SW., Washington, DC 20590, or by e-mail at buck.furrow@rspa.dot.gov.