NTSB Safety Recommendation P-98-014

NTSB safety recommendation P-98-014.

THE NTSB RECOMMENDS THAT THE MIDAMERICAN ENERGY CORPORATION: MODIFY YOUR GAS CONSTRUCTION TO REQUIRE (1) FIRM COMPACTED SUPPORT UNDER PLASTIC CONNECTIONS TO STEEL MAINS, & (2) THE PROPER DESIGN & POSITIONING OF PROTECTION SLEEVES AT THESE CONNECTIONS.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1998-04-30

Adopted Date: 1998-04-23

Overall Date Closed: 1999-04-07

Synopsis: DESPITE THE GENERAL ACCEPTANCE OF PLASTIC PIPING AS A SAFE & ECONOMICAL ALTERNATIVE TO PIPING MADE OF STEEL OR OTHER MATERIALS, THE BOARD NOTES THAT A NUMBER OF PIPELINE ACCIDENTS IT HAS INVESTIGATED HAVE INVOLVED PLASTIC PIPING THAT CRACKED IN A BRITTLE-LIKE MANNER. FOR EXAMPLE, ON 10/17/94, AN EXPLOSION & FIRE IN WATERLOO, IOWA, DESTROYED A BUILDING & DAMAGED OTHER PROPERTY. SIX PERSONS DIED & SEVEN WERE INJURED IN THE ACCIDENT. THE BOARD INVESTIGATION DETERMINED THAT NATURAL GAS HAS BEEN RELEASED FROM A PLASTIC SERVICE PIPE THAT HAD FAILED IN A BRITTLE-LIKE MANNER AT A CONNECTION TO A STEEL MAIN.

Probable Cause: None

Ntsbnumber: DCA95MP001

Report Number: SIR-98-01

Addressee Name: MidAmerican Energy Corporation

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1999-04-07

Addressee Organization Type: P-Private Industry

Communication Date: 1998-06-10

Communication Type: Official Correspondence

Communication Contents: (Letter Mail Controlled 6/15/98 3:24:12 PM MC# 980766) MIDAMERICAN AGREES THAT PROPERLY DESIGNED & POSITIONED SLEEVES AT THESE CONNECTIONS ARE A GOOD PRACTICE.

Addressee Organization Type: P-Private Industry

Communication Date: 1999-02-09

Communication Type: Official Correspondence

Communication Contents: Letter Mail Controlled 2/12/99 3:00:46 PM MC# 990142 MIDAMERICAN HAS DEVELOPED STANDARDS THAT REQUIRE ADEQUATE COMPACTION OF SOIL AT THE PLASTIC SERVICE TO STEEL MAIN CONNECTION. MIDAMERICAN HAS ALSO REQUIRED THE USE OF PROTECTIVE SLEEVES AT PLASTIC SERVICE TO STEEL MAIN CONNECTIONS THAT ARE PROPERLY DESIGNED AND POSITIONS. THE CHANGES TO THE STANDARD WERE APPROVED BY THE MIDAMERICAN STANDARDS COMMITTEE, ISSUED TO THE FIELD, AND BECAME EFFECTIVE 10/21/98. THE CHANGES MADE TO THE STANDARD ARE CONSISTENT WITH ACTUAL FIELD PRACTICES THAT HAVE BEEN IN PLACE FOR MANY YEARS. MIDAMERICAN ENERGY REQUESTS THAT THE NTSB CLASSIFY P-98-14 AS CLOSED.

Addressee Organization Type: P-Private Industry

Communication Date: 1998-07-23

Communication Type: Official Correspondence

Communication Contents: THE BOARD UNDERSTANDS THAT MIDAMERICAN WILL ADD LANGUAGE TO ITS CONSTRUCTION PRACTICES TO REQUIRE FIRM COMPACTED SUPPORT UNDER ITS PLASTIC SERVICE CONNECTION TO STEEL MAINS. THE BOARD IS PLEASED, ACCORDINGLY, P-98-14 HAS BEEN CLASSIFIED "OPEN--ACCEPTABLE RESPONSE," PENDING FURTHER INFO FROM MIDAMERICAN ON COMPLETION OF THE EFFORT TO ADD LANGUAGE TO ITS CONSTRUCTION PRACTICES & TO REQUIRE FIRM COMPACTED SUPPORT UNDER ITS PLASTIC SERVICE CONNECTIONS TO STEEL MAINS, AS WELL AS AN UPDATE ON MIDAMERICAN'S ACTION TO REQUIRE THAT SLEEVES IT ALREADY USES AT THESE CONNECTION ARE PROPERLY DESIGNED & POSITIONED.

Addressee Organization Type: P-Private Industry

Communication Date: 1999-04-07

Communication Type: Official Correspondence

Communication Contents: THE SAFETY BOARD IS PLEASED THAT MIDAMERICAN HAS DEVELOPED STANDARDS THAT REQUIRE ADEQUATE COMPACTION OF SOIL AT THE PLASTIC SERVICE TO STEEL MAIN CONNECTIONS AND THAT MIDAMERICAN NOW REQUIRES THE USE OF PROPERLY DESIGNED AND POSITIONED PROTECTIVE SLEEVES AT PLASTIC SERVICE TO STEEL MAIN CONNECTIONS. ACCORDINGLY, P-98-14 HAS BEEN CLASSIFIED "CLOSED--ACCEPTABLE ACTION."