1、Lessons Learned Entry: 0488Lesson Info:a71 Lesson Number: 0488a71 Lesson Date: 1997-01-01a71 Submitting Organization: JSCa71 Submitted by: L. UnderwoodSubject: Vacuum Pump Outlet Hazard Description of Driving Event: Technicians were performing a maintenance operation on a Mazak CNC milling machine v
2、acuum pump when a glass oil mist separator bowl burst. The subject bowl was attached to the discharge of a 3 hp Gast pump. This particular pump has the capability of producing 15 psi at the outlet if restricted. The rated pressure of the glass bowl is 5 psi, which is clearly marked with a warning re
3、garding breakage. Prior to the incident, the pump had undergone overhaul and, after reinstalling the pump, the technicians operated it in order to circulate its lubrication oil. Once oil circulation was verified, the pump was restarted and the glass oil separator bowl ruptured. Fortunately, no one w
4、as injured by the broken glass. The technicians performing the task stated that there was no known restriction in the discharge piping downstream of the separator. It should also be noted that an identical separator is installed on the inlet of the vacuum pump. The incident prompted an investigation
5、 of other similar installations in the facility. The result was that a total of 3 machines are using the same oil separator configuration as the subject machine. These separators are factory installed and are standard equipment on these type of machines. To prevent injury from unanticipated glass fr
6、agmentation due to overpressurization of the oil separator, maintenance management personnel decided to install a wire cage around the pump discharge.Lesson(s) Learned: Restriction of vacuum pump discharge may cause rupture of exhaust components.Recommendation(s): Install a wire cage around the pump
7、 outlet line discharge or replace the open exhaust fitting with an extension drilled with holes along the side as well as an open end. This will prevent inadvertent blockage of a single port that may lead to over pressurization of the oil mist separator jar.Provided by IHSNot for ResaleNo reproducti
8、on or networking permitted without license from IHS-,-,-Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Hardwarea71 Industrial OperationsAdditional Info: Approval Info: a71 Approval Date: 1997-02-18a71 Approval Name: Ron Montaguea71 Approval Organization: NA3a71 Approval Phone Number: 281-483-8576Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
