RESPONSE_TO_BIDDER_QUESTIONS_6-4-18.docx

80KSC018R0016

QUESTION & ANSWERS 6/4/18

RESPONSE TO BIDDER QUESTIONS:

1. REFERENCE: J-B-80 states that a deposit launch residue will be present and from Launch SLS EM-1 and will need to be cleaned and removed by the contractor.

QUESTION: Can you clarify what type of procedure or system is needed in order to remove the residue? Just pressure wash, or is a specialty application required?

ANSWER: There is no special procedure for removal of launch residue as referenced in Clause J-B-80. NASA’s operations typically only use water to remove launch residue. Certain materials and assemblies within the contract have specific surface preparations and cleanliness requirements at certain points in fabrication that could drive more processes for removal of launch residue, but that is for the contractor to assess. Resurfacing is referenced as the contractor’s responsibility in case any coatings or surface finishes are damaged by launch residue or the contractor’s subsequent process chosen for removal of launch residue.

1. REFERENCE: Spec: 79K40362; Sec: 43 42 41.99; Par: 3.1.6 QUESTION: Does minus 452 degrees Fahrenheit only apply to the welding Procedure Qualification Record (PQR), or is it also required on the Production Test Plates (PTP’s) and filler metal pre-use testing? Does minus 452 degrees Fahrenheit only apply to the base metal, or does it also apply to the Heat-Affected Zone (HAZ) and weld metal?

ANSWER: As specified in BPVC VIII, Div 1, part UHA-51, or Div 2, part 3.11.4, no exemptions from impact testing can be applied. Consequently, the impact weld toughness test applies to welding procedure qualification and vessel production impact test plates. Additionally, the impact weld toughness test applies to base metal, heat-affected zone and weld metal.

1. REFERENCE: (Q&A #5 5/31/18) Spec: 79K40362; Sec: 43 42 41.99; Par: 3.1.6 QUESTION: What is the acceptance criteria for the Weld Impact Tests at minus 452 degrees Fahrenheit that has to be met?

ANSWER: (REVISED) Impact testing shall be completed in accordance with either BPVC VIII, Div 1, part UHA-51(a)(3) or Div 2, part 3.11.4.1(c), as applicable.

1. REFERENCE: (Q&A #6 5/31/18) Spec: 79K40362; Sec: 43 42 41.99; Par: 3.1.6 QUESTION: Does this also apply to the heat exchanger subcontractor?

ANSWER: (REVISED) As specified in Section 40 29 98, internal heat exchanger piping shall be fabricated in accordance with ASME B31.3 and constructed from 316L tubing per ASTM A269. Per Table A-1, for listed material the design minimum temperature is -425 deg F. In accordance with 323.2.2(c), for use at -452 deg F, impact testing is required.

1. REFERENCE: Spec: 79K40362; Sec: 43 42 41.99; Par: 3.1.6

QUESTION: The scope of work to be performed will be in accordance with ASME BPVC Section VIII, Division 2. UG-84 in Division 1 is similar to 3.11.7 in Division 2. This section is for Toughness Testing Procedures, and it mentions that the impact test temperature shall not be warmer than the MDMT, which is minus 452 degrees Fahrenheit. However, under section 3.11.4.1, Toughness Requirements for High Alloy Steels, 3.11.4.1(c) provides specific requirements when the MDMT is colder than minus 320 degrees Fahrenheit. 3.11.4.1(c)(1)(-b): “Toughness tests shall be conducted at −196°C (−320°F) on three sets of three specimens: one set from the base metal, one set from the weld metal, one set from the HAZ.” Does NASA require impact testing to be performed at minus 452 degrees Fahrenheit, or is impact testing at minus 320 degrees Fahrenheit per the code acceptable?

ANSWER: As specified by the reference, the requirement is for impact testing to be completed at -320 deg F in accordance with either BPVC VIII, Div 1, part UHA-51(a)(3) or Div 2, part 3.11.4.1(c), as applicable, with all other listed conditions being satisfied.

1. REFERENCE: DWG: 79K40361; Sheets 120, 123, and 125 (drawings MC100, MC103, and MC300 respectively) Spec. 40 29 99; Par: 3.4, 3.7.1, 3.7.2, & 3.7.3 QUESTION: Note H on drawing MC100 details vacuum jacketed connection to existing, and associated mods to the 12” vent at that connection point. This is further detailed by reference in MC103 with flags to the details on MC300. These are new weld joints to the existing line that require NDE, pressure testing, passivation/cleaning, and cold shocking as per the spec. references noted above. No detail is provided for the existing line to determine the large quantities of process and testing mediums (Cleaning solutions, LN2, GHE, etc.) that would be required to accomplish this task using conventional means. Please confirm if it would be acceptable at the weld joints to existing pipe that the following be accomplished: Local clean (prior to weld) inside and out, NDE (Visual & RT), external passivation of the weld, and local cold shock. Internal weld passivation, post interior-weld cleaning, mass spec testing or pressure testing would not be accomplished for these specific joints.

Otherwise, please provide information on both affected lines, as to the existing system boundaries, where we have isolatable points and existing ports to accomplish all of these actions. Please advise.

ANSWER: The contractor is required to submit test and cleaning procedures for approval as required by the specification, wherein means and methods for each pipe section would be identified by the contractor, as necessary. Local cleaning only would be expected for this particular point of connection. Careful selection of fluids/solutions is required in order to not contaminate the piping. Only local cold shock of the welds would be expected for this section. A method of internal cleaning could be accomplished by different methods of pipe pigging by temporary removal of non-welded components in the existing line.

Pressure testing would be pneumatic, with the following estimated isolation lengths of existing piping:

For the 12" Dia. Vent Line, an approximate 540 feet segment can be isolated (or 240 feet by removing a hinged expansion joint) for the testing. For the 10"x12" VJ piping, there is no easy isolation and a segment of approximately 1300 feet of existing piping would be involved.

1. REFERENCE: Drawing T-004

QUESTION: We have been unable to locate the cable subassemblies for KGCS-01, KGCS-02, KGCS-03 & KGCS-04. Please provide this information.

ANSWER: What is identified for these cable subassemblies is actually the Dow Corning part number for the cable, not a subassembly. Provide same cable or equal.