Memo: Internal — Pipeline Safety Interpretation

Page 1September 14, 1983 INFORMATION: Questions on Section 192.625, Odorization of Gas Richard L. Beam Associate Director for Pipeline Safety Regulation, DMT-30 James C. Thomas Chief, Southern Region, OOE, DMT-16 THRU: Robert L. Paullin Associate Director for Operations & Enforcement, DMT-10 Your memo of June 9, 1983, asks questions based on conditions listed in five cases relating to the odorization requirements of §192.625. The information provided on Cases 1, 2, and 3 is inadequate for us to determine whether the lines involved are distribution or transmission, or are transmission that may be excepted under §192.625(b)(2) or (3). Therefore, we cannot make a determination as to the need for odorization. In the conditions described in Case 4, the pipeline may be odorized at any point that would ensure detectability of appropriate concentrations in air (one fifth of the explosive limit) along the entire length of pipeline (§192.625(a)). The most likely location would be at the closest practicable point just downstream of the tap. While §192.625 does not specifically prohibit introducing the odorant on the consumer's piping, it is highly unlikely that odorant introduced at this point would in fact odorize all of the pipeline required to be odorized upstream of the sales meter. In response to Case 5, the nature of the commerce the company conducts does not affect the classification of the line under §192.3. Cases 1 and 3 would be affected if the line terminates at a large volume customer because the line may be a transmission line and might be exempt from odorization under §192.625(b). The decision in Case 2 would not be affected because the line is already in the transmission category. dal\192\625\83-09-14 1#

Page 2Date: June 9, 1983 Subj: ACTION: Odorization Interpretations From: James C. Thomas, Chief Southern Region, Pipeline Safety, DMT-16 To: Thru: Richard L. Beam, Associate Director, OPSR, DMT-30 Robert L. Paullin, Associate Director, OOE, DMT-10 Interpretations concerning the odorization of certain pipelines need further clarification for the proper enforcement of this rule. Therefore, I request that the OPSR respond to the following questions relating to Section 192.625. Are the following pipelines serving gas to one customer required to be odorized at some point between the tap on the source line and the sales meter? (Assume that the source line is legally unodorized and that the presence of odorant would not harm the customer). 1. Direct sales line, owned by an interstate operator and operating at a hoop stress less than 20% SMYS. 2. Same as 1. above except operating at or above 20% SMYS. 3. Same as 2. above except that the downstream line section operates at less than 20% SMYS between the pressure limiting device and the sales meter. 4. In the above examples that do require odorization, at what place on the line segment must the odorization equipment be located? (For example, the closest most practicable point just downstream of the tap, or at any place on the pipeline? Could it be installed downstream of the sales meter on customer piping? 5. In situations 1., 2., and 3. above, would the answers remain the same if the pipeline serving gas to one customer was owned and operated by an intrastate dal\192\625\83-09-14 2#

Page 3company? Would the answers be affected by whether the line terminates at a "large volume customer" or not? # dal\192\625\83-09-14 3#