1、Public Lessons Learned Entry: 5156 Lesson Info: Lesson Number: 5156 Submitting Organization: KSC Submitted by: Dawn Martin Subject: Pad-39A Sandblast Pot Mishap Abstract: A worker disconnected a hose from the vent pipe attached to a sandblast pot, the stored pressure energy in the pot caused the pip
2、e to spin, and the worker was struck several times by the spinning vent pipe. The injured worker and several others involved in the sandblasting operation were employed under a subcontract to perform corrosion control, including sandblasting and painting. The oversight of equipment configuration and
3、 operations delegated to subcontractors can lead to unsafe operations. All pressure system maintenance should be performed by approved procedures that ensure configuration control and prime contractors should explicitly identify in their subcontracts the maintenance that subcontractors are authorize
4、d to perform without obtaining prime-contractor approval. Description of Driving Event: On July 19, 2006, at approximately 0714, Eastern Daylight Time, a sandblasting worker was struck several times by a spinning vent pipe assembly (consisting of 2-inch galvanized-steel pipes and fittings and a 2-in
5、ch bronze vent valve) attached to a sandblast pot while preparing for sandblast operations at the Kennedy Space Center (KSC) Launch Complex 39A (Pad 39A). Security, Fire/Rescue, and Emergency Medical Services (EMS) personnel arrived at the scene within a few minutes, and the injured worker was airli
6、fted to a nearby medical center. The injured worker and several others involved in the sandblasting operation were employed under a subcontract to perform corrosion control, including sandblasting and painting. The mishap involved the unsafe configuration of the sandblast pot due to the following de
7、ficiencies in the initial system setup of the pressure vessel/systems (PV/S): No safety relief valve (SRV) in the system was set at or below the maximum allowable working pressure (MAWP) of the sandblast pot (lowest-rated component in the system), as required by the American Society of Mechanical En
8、gineers (ASME). The sandblast pot was not equipped with a pressure gage or SRV as required by OSHA 29 CFR. Operating pressure was set higher than the sandblast pot (receiver) MAWP. The manufacturers certification was voided by postmanufacturing welds on the pressure vessel. The SRVs on the compresso
9、r and dryer did not open at the designated settings of the valves. The compressor SRV was missing the appropriate manufacturers identification plate. Flex hoses and other components of the dryer were in disrepair. Lesson(s) Learned: Fixed Priced Contractors (FPC) construction subcontractors oversigh
10、t did not discover the unsafe configuration of the sandblast pot. The quality and focus of the oversight of equipment configuration and operations delegated to subcontractors can lead to unsafe operations. Recommendation(s): 1. Ensure the inventory of pressure vessels is known, that the certificatio
11、n of these vessels is in accordance with your safety requirements, and that your pressure vessel safety requirements are clear, concise, and comprehensive. 2. Ensure that modifications to pressure systems are managed and controlled by configuration management in order to ensure that safety is not co
12、mpromised regardless of ownership at the Center. All pressure system maintenance should be performed by approved procedures that ensure configuration control, including the use and approval of parts that are not from the original equipment manufacturer (OEM). 3. Ensure that modifications to Commeric
13、al Off The Shelf (COTS) equipment goes through an approval by the manufacturer and/or an approval by the Centers safety engineering organization. Also, a documented process to should be developed and followed. 4. Ensure that daily safety inspections are performed and that those records are maintaine
14、d. 5. Ensure that field maintenance is performed by the responsible equipment owner in accordance with manufacturer requirements. 6. All KSC prime contractors who manage PV/S at KSC should explicitly identify in their subcontracts the maintenance that subcontractors are authorized to perform without
15、 obtaining prime-contractor approval. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Evidence of Recurrence Control Effectiveness: N/A Documents Related to Lesson: KNPR 8715.3 KSC Safety Practices Procedural Requirements NASA STD 8719.17 NASA Requir
16、ements for Ground-Based Pressure Vessels and Pressurized Systems KSC-PLN-2807 Mishap Contingency Plan Mission Directorate(s): Exploration Systems Additional Key Phrase(s): Facilities Review systems and boards Maintenance Configuration Change Control Role of Civil Service Technical Staff versus Contr
17、actor Staff Risk Management Contractor Relationships Communications between Different Offices and Contractor Personnel Acquisition / Procurement Strategy and Planning Pressure Vessels Additional Info: Project: Shuttle Program Approval Info: Approval Date: 2011-02-16 Approval Name: mbell Approval Organization: HQ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
