Text For Citation: 01 Item/Group: 003C Hazard: REFINERY

29 CFR 1910.119(d)(3)(ii) The employer shall document that equipment complies with recognized and generally accepted good engineering practices. A) At Big West Oil, 333 W Center Street, North Salt Lake, UT 84054, the employer did not document that pressure safety valve PSV-5590 complies with RAGAGEP. The inlet line pressure drop (ILPD) for PSV-5590 is 6.4which exceeds the 3of the opening set pressure as described in the RAGAGEP. PSV-5590 was identified as having an ILPD greater than 3by the employer (BWO UOSH-092-0003). The inlet line pressure drop is associated with pressure losses as the relieving fluid; vapor or two-phase flow passes through all the piping and fittings (ells, valves, etc.) from the vessel to the pressure safety valve (PSV). If relieving flow is choked by the inlet line losses, the protected vessel could catastrophically fail. ILPD is a phenomenon where a PSV can open at its set pressure as designed. Due to the ILPD, the PSV closes quickly due to the decrease in pressure caused by the ILPD and not the actual pressure in the equipment which initially caused the pressure to exceed the set pressure of the PSV. After the PSV closes due to the ILPD, it will open again due to the actual pressure in the equipment is higher than the set pressure. This continual opening and closing of the PSV is termed chattering. This chattering can occur many times. As a result the capacity of the PSV is reduced and the chattering can cause, in the worst case, the relief system equipment to catastrophically fail with an ensuing loss of containment of hazardous chemicals. Equipment that is not documented in complying with recognized and generally accepted good engineering practices prevents the employer from ensuring the adequacy of process equipment and may result in employee exposures to hazardous chemicals. This may be a system-wide occurrence that requires evaluation of all procedures throughout the facility. B) At Big West Oil, 333 W Center Street, North Salt Lake, UT 84054, the employer did not document that pressure safety valve PSV-3307 in the Alky Unit complies with RAGAGEP. The total backpressure on this valve exceeded approximately 50of the valve's set pressure. The employer provided the following requested information regarding balanced-bellows PSV- 3307 in the Alky Unit (BWO UOSH-092-0003). 1.Set Pressure = 175 psig 2.superimposed back pressure at outlet of relief device PSV-3307 is typically less than 5psig 3.built-up backpressure after relief device PSV-3307 opens = 100 psig Total backpressure (superimposed plus built-up) equals 105 psig and this is 60of the valve's set pressure (175 psig). RAGAGEP recommends that total backpressure should not exceed approximately 50of the valve's set pressure. This guidance is offered in Section 3.3.3.2.1 of the 2000 API 520 which states: "Balanced valves can typically be applied where the total backpressure (superimposed plus built-up) does not exceed approximately 50of the set pressure". Reduced flow capacity through the valve may occur as high backpressure will tend to produce a closing force on the unbalanced portion of the valve's disc and may result in employee exposures to hazardous chemicals. This may be a system-wide occurrence that requires evaluation of all procedures throughout the facility. (C) The employer did not comply with Recognized and Generally Accepted Good Engineering Practices (RAGAGEP) when developing their facility siting study. The facility siting study is develop to determine if the employees inside permanent or temporary structures were protected (i.e., protected by adequate separation or building construction) structures that were exposed to explosion, fire, toxic material, corrosive materials such as HF or high pressure hazards as a result of an HHC release from process equipment. At the time of inspection, May 2010 to September 2010, Big West Oil LLC (BWO), 333 W. Center St., North Salt Lake City, UT 84054, the Compliance Officer observed that employer did not conduct a refinery-wide facility siting study for its occupied permanent and temporary buildings in accordance with RAGAGAP, API 752 and API 753. The Compliance Audit report of March 2009, BWO-UOSH-039B-0014, stated that the refinery did not have a facility siting study and recommended a study should be done. A facility siting study, BWO- UOSH-052-0001, was submitted to UOSH and found that it was not in compliance with RAGAGAP. Another study was contracted on June 2010 to ABS Consulting. The BWO PSM Coordinator stated that the contractor had done their field work at the refinery in the first week of August 2010, but their final report of the study was not available at the end of this inspection. As a result, employees and contractors were exposed to hazardous condition which could result in serious injuries or death in the event of a catastrophic event. This may be a system-wide occurrence that requires evaluation of permanent and temporary structures throughout the facility.