The ammonia chillers are suitable for outdoor installation. The units are designed to operate with ammonia refrigerant (R717). This Piping Handbook is intended to guide the reader through the process of successfully designing and implementing DX Ammonia from +50F to r50F and realizing the benefits of: r Dramatically reduced ammonia charge r Simplified controls r Energy efficient dry suction line r Reduced line sizes r Elimination of ammonia recirculator pumps II.

• Ammonia Piping Specifications

OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed.

Ammonia Piping Specifications

Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at.Response 10 updated July 07, 2015.July 12, 2006Mr. Palmer, Jr.Environmental Attorney/ConsultantLAMB GROUP, LLC.330 Providence RoadAthens, GA 30606Dear Mr.

Palmer:This is in response to your letter dated August 22, 2004, to the Occupational Safety and Health Administration (OSHA) regarding several questions pertaining to OSHA standards, including OSHA Process Safety Management (PSM) standard at 29 CFR 1910.119. You indicated in your letter that your consulting group provides environmental and safety consultation in the PSM area. You also indicated that majority of your clients operate ammonia refrigeration systems to provide cooling necessary to the production of food products. This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any questions not delineated within your original correspondence. We apologize for the delay in our response.

Your paraphrased questions, scenarios, and our responses are provided below.Question 1: How long should Management of Change (MOC) documentation be kept under the PSM standard?Response 1: As you may know, the safe operation of chemical processes is based in part on the original design or design basis/intent of a process. The original design and design intent are used in the chemical industry as the basis for the fabrication, installation, start-up, operation, maintenance, and changes to a process.

The development and use of the original design and design intent are recognized and generally accepted good engineering practice (RAGAGEP) for covered processes and are explicitly required by OSHA PSM standards such as 1910.119(d)(3)(i)(D); 1910.119(d)(3)(i)(F); and 1910.119(j)(6)(ii). The OSHA PSM standards implicitly require the employer to develop and use the original design and design intent, such as 1910.119(d)(3)(i)(A) and 1910.119(d)(3)(i)(C); 1910.119(d)(3)(ii); and 1910.119(j)(6)(i).Consequently, it is important for continued safe operation that when employers contemplate changes to covered processes they have access to the original design or design intent for that process and its equipment. This is especially true as a result of high turnover of personnel who are responsible for the safety of these processes and who must know the design history and design intent, including any subsequent changes. Employers need this information so they may safely address the technical basis 1910.119(l)(2)(i) for any new MOC procedure and to determine, as a result, whether the safety and health impacts 1910.119(l)(2)(ii) of any new MOC procedure have been adequately determined.As PSM is a performance-oriented standard, 29 CFR §1910.119(l) does not explicitly specify the manner and the duration for which an employer must maintain MOC documentation.

Because the original design, design intent, and all subsequent changes are important for the continued safe operation of a covered process, pursuant to 29 CFR 1910.119(l)(4) MOCs addressing chemicals and equipment would become part of the Process Safety Information (PSI), giving employers a documented record of, not only the original design and design intent of the covered process, but also providing a record of all changes to the process that are of importance to those responsible for safe operation and maintenance and to those that may need to consider future changes to the process. Consequently, MOCs for chemicals or equipment in a covered process must be retained for the life of the process through their incorporation in the PSI pursuant to 29 CFR §1910.119(l)(4).If an employer conducts an MOC related to changing procedures and practices 1910.119(l)(5), OSHA would only require the employer to retain that particular MOC procedure until it is incorporated into the next process hazard analysis (PHA) revalidation or update required by 1910.119(e)(6). Therefore, in this case the MOC retention time is based on the PHA revalidation schedule which is established through consultation with employees 1910.119(c)(2) and could be up to a maximum of 5 years.Many times MOCs utilize a large amount of background materials as part of the research and decision making process for the conduct of a MOC. If these background materials are not required to be retained by another OSHA standard, e.g., 1910.119(d), OSHA would not require the employer to retain these materials beyond the time when the MOC is incorporated into the next PHA update or revalidation.Further, per 1910.119(o)(1), OSHA expects the employer to audit a representative number of the MOC procedures it has conducted. Therefore, the employer's MOC retention practices need to assure that a statistically-significant number of representative MOC procedures are available to be audited during the next compliance audit cycle conducted by the employer.The document retention requirements listed above are consistent with industry RAGAGEP. For example, the Center for Chemical Process Safety (CCPS) of the American Institute of Chemical Engineers states that documentation for the design intent/basis of equipment should be available for the life of the process. CCPS also provides RAGAGEP for MOC records retention and purge schedules.

CCPS information on retaining and purging MOC documents include that, at a minimum, the MOC information should be retained up to the next PHA update or revalidation; that no purging of MOC documents be carried out before the next audit; and that there should be a definition and identification process for MOC documents which need to be retained for regulatory purposes and that these documents should not be purged.Question 2: Can the facility start a new MOC log after the completion of the 5-year revalidation Process Hazard Analysis (PHA)?Response 2: OSHA does not require an 'MOC log.' OSHA only requires that MOC procedures be implemented whenever a specified change other than a replacement-in-kind, is contemplated. However, OSHA recommends that an employer utilize some type of tracking process, preferably a computer database, to assure that all MOC procedures are appropriately managed. This is especially important where employers have many MOC procedures in various stages of completion, e.g., under review, on-going, completed.Scenario: A facility repairs a piece of equipment by replacing a part. The initial MOC lists the change to be 'replacement-in-kind.' The facility maintenance manager/engineer, after reviewing the change, determines that the change was a 'replacement-in-kind.' Question 3: For the above scenario, is there any requirement for documenting and maintaining a file to prove to an inspector that the change was in fact a 'replacement-in-kind'?Response 3: No — not with respect to 1910.119(l).

Employers are not required to conduct an MOC when changes are replacement-in-kind.However, OSHA's PSI standard, 1910.119(d)(3), requires that employers compile information related to equipment which is part of the process. This includes all component parts, whether the components are original or replacement (replacement-in-kind or replacements with different design specifications) parts.This is consistent with the RAGAGEP for maintaining up-to-date and accurate data for PSM-covered equipment. For example, CCPS states that maintaining this information is an important element of any facility PSM effort. CCPS states that the useful service life for process equipment includes maintenance, repair, modification, and replacement among other activities.

CCPS explains that, typically, the amount of PSM-related equipment information grows through the equipment/process life cycle, which includes some of the life cycle steps listed. CCPS further states that the generation, compilation, and protection of this information is important and is to be available to appropriate personnel.Question 4: The Hot work permit program under the PSM rule does not specify any record retention period. Is there any requirement to maintain a file of old or closed hot work permits so that an inspector can verify that the program is being followed?Response 4: The PSM standard does not require employers to maintain a file of old or closed hot work permits. 1910.119(k), Hot work permit, does not require hot work permit record retention beyond completion of the hot work operations. Paragraph 1910.119(k)(2) states in part, '. The permit shall be kept on file until completion of the hot work operations.' However, to comply with provisions under paragraph 1910.119(o)(1), an employer must audit the procedures and practices required by PSM and assure they are adequate and are being followed.

Since hot work permits are part of the hot work procedure, OSHA expects that employers would audit a statistically-valid number of hot work permits to assure they were completed and implemented per their procedure. This practice is consistent with industry auditing safe work practices such as CCPS, which states, for example, that the auditor should sample maintenance records to verify that work authorizations and safe work (e.g., hot work) permits have been completed as required. Due to the performance-oriented nature of PSM, how the employer audits its hot work permits/procedure, or any procedure, is a matter of assuring performance (i.e., procedures are developed, adequate, and are being implemented), rather than a matter of OSHA specifying how compliance audits are to be conducted.

One way to audit hot work permits to evaluate compliance with 29 CFR 1910.119(k) is to complete the audit before the permits are discarded.Question 5: Is there any requirement under the PSM rule for an hourly employee (system operator) to be a member of the Process Hazard Analysis Team, Audit Team, or Incident Investigation Team?Response 5: OSHA's PSM standards relating to team composition requirements for PHA, incident investigation, and audit teams are 1910.119(e)(4), 1910.119(m)(3), and 1910.119(o)(2), respectively. Membership on any of these specified teams is not based on compensation. Rather, these team composition requirements are based on an employee's knowledge of and experience with the process which is undergoing a PHA, being investigated, or being audited.With respect to the PHA team composition requirements, the standard requires that the team include at least one employee who has experience and knowledge specific to the process being evaluated.

This provision is in addition to the requirement that the PHA team consist of individuals with e xpertise in engineering and process operations. This employee (who has experience and knowledge specific to the process being evaluated) must in all cases be from the facility and must be intimately familiar with the process.For incident investigation team composition, OSHA standard 1910.119(m)(3) requires that the team include at least one person knowledgeable in the process involved.