REG NASA-LLIS-0238-1993 Lessons Learned - Altitude Exhausters.pdf

1、Lessons Learned Entry: 0238Lesson Info:a71 Lesson Number: 0238a71 Lesson Date: 1993-07-08a71 Submitting Organization: LERCa71 Submitted by: S. PapellSubject: Altitude Exhausters Description of Driving Event: Exhausters were running to provide simulation of altitude conditions in a combustor rig when

2、 the mishap occurred. The equipment operators were short-handed and, as a result, a certain amount of confusion existed. A valve at the discharge end of the exhausters was inadvertently closed. The reduced flow caused the inlet pressure to rise because a continuous quantity of air was being supplied

3、 to the exhauster inlet from the compressors in the system. As a result, the pressure at the exhauster inlet increased to almost atmospheric. The exhausters then became compressors and generated a discharge pressure level high enough to rupture the inverted, dished head of the exhauster header locat

4、ed 50 feet downstream. The inverted, dished head was 8 feet in diameter and 3/8 inches thick located 16 inches underneath the floor level. A hole about 30 feet in diameter was blown in the roof of the building located 35 feet above the floor level. A large number of windows were broken and the reinf

5、orced concrete floor in the vicinity of the rupture was destroyed.Lesson(s) Learned: 1. Exhausters designed for vacuum services can become pumps and cause severe damage to vacuum systems by overpressurization.2. Operators of stationary equipment such as exhausters and compressors can make damaging m

6、istakes when rotated between facilities having different controls and operating procedures.Recommendation(s): 1. Install warning and relief devices in exhaust line piping to prevent accidental excessive pressure build-up.2. Standardize controls, relief devices, and operating procedures for all such

7、facilities so that operator training will be simplified and minimized.Provided by IHSNot for ResaleNo reproduction 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)

8、 a71 Facilitiesa71 Industrial Operationsa71 Pressure VesselsAdditional Info: Approval Info: a71 Approval Date: 1994-06-08a71 Approval Name: Maria Havenhilla71 Approval Organization: LERC/EBASa71 Approval Phone Number: 216-977-1483Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-