Naval Brass Tube Plate Specification (For Condensers and Heat Exchangers)

Naval Brass Tube Plate Specification (For Condensers and Heat Exchangers)

1.0 NAVAL BRASS TUBE PLATE GENERAL

This specification defines the quality, manufacturing, testing, and acceptance criteria for Naval Brass (C46400) tube plates intended for use in condensers, heat exchangers, and pressure vessels under demanding operational conditions (e.g., high temperature, pressure, and corrosive environments).

2.0 NAVAL BRASS TUBE PLATE SCOPE OF APPLICATION

• Primary Use: Fabrication of tube sheets for shell-and-tube heat exchangers, condensers, and marine applications.
• Service Conditions: Suitable for operating temperatures up to 300°C and pressures not exceeding 20 MPa, in contact with seawater, steam, or mildly acidic/alkaline media.

3.0 NAVAL BRASS TUBE PLATE DELIVERY CONDITION

• Manufacturing Process:
  • Hot Rolling: Initial forming via controlled hot rolling to achieve near-net dimensions.
  • Cold Working: Final dimensional adjustments through cold rolling or drawing, followed by stress-relief annealing (650–750°C, air-cooled) to ensure mechanical properties.
• Surface Finish:
  • Free from scale, pits, burrs, and rolling marks.
  • Surface roughness: Ra ≤ 3.2 μm (measured per ASTM D7127).
• Edge Condition: Cut edges shall be smooth, deburred, and free of tears or jaggedness.

4.0 NAVAL BRASS TUBE PLATE MATERIAL STANDARD

• Alloy Designation: UNS C46400 (Naval Brass) conforming to ASME SB-171M (latest edition and addenda).
• Prohibited Substitutions: No alternative materials or standards permitted without written approval from the purchaser.

5.0 NAVAL BRASS TUBE PLATE DIMENSIONS AND TOLERANCES

5.1 Nominal Dimensions

• Thickness Range: 10–50 mm (standard), custom sizes negotiable.
• Width/Length: 1000–3000 mm (width), 2000–6000 mm (length).
• Hole Pattern: Tube hole diameters, pitch, and layout as per purchaser’s drawings.

5.2 Tolerances

• Thickness: ±5% of nominal (per ASME SB-171M), tighter tolerances (±3%) achievable upon request.
• Flatness: ≤1.5 mm/m; localized deviations exceeding limits require corrective straightening.
• Hole Diameter: ±0.1 mm (reamed holes), ±0.2 mm (drilled holes).

6.0 NAVAL BRASS TUBE PLATE SURFACE QUALITY AND DEFECT CONTROL

• Visual Inspection: 100% surface examination per ASTM A480.
  • Acceptance Criteria: No cracks, seams, laminations, porosity, or embedded foreign materials.
  • Edge Defects: Chamfer edges to 0.5–1.0 mm radius if microcracks are detected.
• Non-Visual Testing:
  • Liquid Penetrant Testing (PT): ASTM E165 for critical applications.
  • Magnetic Particle Testing (MT): ASTM E709 (if ferromagnetic inclusions suspected).

7.0 NAVAL BRASS TUBE PLATE NON-DESTRUCTIVE TESTING (NDT)

• Ultrasonic Testing (UT):
  • Standard: SA-578M (ASME Sec II Part A), Level B acceptance.
  • Procedure: Full-volume scanning with 2–5 MHz dual-element probes; calibration using φ3 mm FBH (flat-bottom hole).
  • Reporting: Map defect locations, amplitudes, and orientations; include operator certifications (ASNT Level II or equivalent).
• Radiographic Testing (RT): Optional for thickness >30 mm (ASTM E94).

8.0 NAVAL BRASS TUBE PLATE CHEMICAL COMPOSITION

• Composition Limits (wt%, per SB-171M):

• Sampling Frequency: One sample per melt lot + one per 4550 kg of finished product.

9.0 NAVAL BRASS TUBE PLATE TEST SAMPLES AND PREPARATION

9.1 Chemical Analysis

• Sampling Method:
  • Melt Analysis: Samples taken during pouring; one per heat.
  • Product Analysis: Drillings from mid-thickness of the plate.

9.2 Mechanical Testing

• Tensile Specimens:
  • Orientation: Longitudinal to rolling direction; extracted ≥50 mm from plate edges.
  • Quantity: One per plate; two for plates >20 mm thickness.
• Hardness Testing: Brinell (HBW 10/3000) per ASTM E10; three readings per plate.

10.0 NAVAL BRASS TUBE PLATE MECHANICAL PROPERTIES

• Requirements (at 20°C):

• Retest Policy: Double samples tested if initial results fail; entire lot rejected if retest fails.

11.0 NAVAL BRASS TUBE PLATE DOCUMENTATION REQUIREMENTS

1. Material Test Report (MTR): Includes heat number, dimensions, chemical analysis, mechanical properties, NDT results, and heat treatment records.
2. Process Flow Chart: Details melting, rolling, annealing, and inspection stages.
3. NDT Reports: UT/PT/MT/RT records with defect maps and operator qualifications.
4. Certification of Conformance: Signed declaration of compliance with ASME SB-171M.

12.0 NAVAL BRASS TUBE PLATE RETEST AND REJECTION

• Retest Protocol: Conducted in presence of purchaser’s representative; third-party arbitration (e.g., Lloyd’s Register) applies for disputes.
• Non-Conforming Material: Clearly marked “REJECTED” and segregated; disposal subject to purchaser’s approval.

13.0 NAVAL BRASS TUBE PLATE TEST CERTIFICATES

• Content: Supplier name, material grade, heat number, dimensions, test results, inspection dates, and ASME code references.
• Delivery: Three original copies + one electronic copy (PDF); hardcopy enclosed with shipment.

14.0 NAVAL BRASS TUBE PLATE MARKING, PACKING, AND SHIPPING

• Marking:
  • Stencil or etch heat number, thickness, and “NAVAL BRASS C46400” on each plate.
  • Label packages with gross/net weight, handling symbols ( “Keep Dry”, ↑ “This Side Up”).
• Packaging:
  • Separate plates with anti-corrosive paper (VCI type); protect edges with PVC caps.
  • Securely crate for sea/road freight; ISO-compliant for export.

Notes:

• Deviations from this specification require prior written approval.
• All testing shall comply with the latest editions of ASME, ASTM, and ISO standards referenced herein.

Naval Brass Tube Plate