MIL-STD-1627 Revision C:1994

1 Scope
1.1 Scope
2 Applicable documents
2.1 Government documents
2.1.1 Specifications, standards, and handbooks
2.2 Non-government publications
2.3 Order of precedence
3 DEFINITIONS
3.1 Activity
3.1.1 Authorized representative
3.2 Backwall
3.3 Bend radius
3.4 Bending machines
3.4.1 Bending machine - Ram type
3.4.2 Bending machine - Roll type
3.4.3 Bending machine - Compression type
3.4.4 Bending machine - Rotary type
3.4.5 Bending machine - Rotary type with a booster
3.5 Buckles and bulges
3.6 Cold bending
3.7 Crack
3.8 Dent
3.9 Flatness
3.10 Gouge
3.11 Hot bending
3.12 Hump
3.13 Minimum design wall thickness
3.14 Pipe
3.15 Qualified
3.16 Step
3.17 Wrinkles
4 GENERAL REQUIREMENTS
4.1 Material
4.1.1 Base material condition
4.1.2 Base material cleanliness
4.1.3 Wall thickness
4.1.4 Surface condition
4.2 Lubricants
4.2.1 Unacceptable lubricant ingredients
4.3 Cleaning
4.4 Loose fillers
4.5 Material control
5 DETAILED REQUIREMENTS
5.1 Bending procedures
5.2 Bending procedure qualification
5.2.1 Production bends as qualification test
5.2.2 Bending machine qualification
5.2.3 Alternative procedures
5.2.4 Qualification test approval
5.2.5 Previously qualified procedures
5.2.6 Vendor qualification
5.2.7 Transferral of qualification
5.3 Qualification test
5.3.1 Sampling
5.3.2 Special requirements
5.3.3 Qualification bends
5.4 Bending criteria
5.4.1 Minimum bend radius
5.4.2 Bending of longitudinally welded pipe
5.4.3 Marking
5.4.4 Bending temperatures
5.5 Hot bending
5.5.1 Heating of pipes
5.5.1.1 Torch heating
5.5.2 Temperature measurements during heating and bending
5.6 Adjustments and corrections
5.6.1 Bend angle adjustment on the closing direction
5.6.2 Bend angle adjustment in the opening direction
5.6.3 Reverse bending
5.6.4 Corrections for out-of-round, buckles, bulges and dents
5.7 Post bending heat treatment
5.7.1 General
5.7.2 Cleaning prior to heat treatment
5.7.3 Procedure
5.8 Inspection
5.8.1 Inspection procedures
5.8.2 Sampling
5.8.3 Inspection personnel
5.9 Acceptance standards
5.9.1 Surface conditions
5.9.1.1 Cracks
5.9.1.2 Pits, gouges, scratches and tool marks
5.9.1.3 Wrinkles
5.9.1.4 Buckles, bulges, humps, steps and dents
5.9.1.5 Flatness
5.9.2 Dimensional
5.9.2.1 Out-of-roundness
5.9.2.2 Wall thickness measurement
6 NOTES
6.1 Intended use
6.2 Acquisition requirements
6.3 Obsolete specifications referenced by this standard
6.4 Maintenance of records
6.5 Subject term (key word) listing
6.6 Changes from previous issue
FIGURES
1 Types of bending machines
2 Location of weld for welded pipe
3 Calculations for buckles, bulges, humps, steps and
      dents in pipe bends
4 Flatness limits
TABLES
I Grouping of base material
II Cold and hot bending temperatures
III Post bending heat treatment
IV Post bending heat treatment temperatures and mode of
      cooling

Specifies pipe bending, heat treatment, inspection and acceptance criteria for piping in US Navy ships.