In March 2025, we received an RFQ from a UAE-based heat exchanger fabricator serving a district cooling project in Dubai industrial area.
The client is a mid-to-large fabrication company that regularly supplies:
Shell & tube heat exchangers
Condensers
Cooling system equipment
Their projects are typically delivered to contractors involved in district cooling and seawater circulation systems in the Gulf region.
How the Project Started
The inquiry came with:
A basic specification sheet
General dimensions of the tube plates
Material requirement: ASTM SB171 C46400
However, the detailed drilling drawings were not finalized yet.
Key Discussion Points
During email and technical discussions, the client focused on:
Whether the material is suitable for high salinity seawater
Internal quality (to avoid failure during tube drilling)
Flatness tolerance for CNC drilling machines
They mentioned a previous issue:
During drilling, some tube sheets showed minor porosity, causing rework and delays.
Final Confirmed Order Details
After 2 rounds of technical confirmation, the order was finalized as:
Material: Naval Brass C46400 (ASTM SB171)
Size:
Width: 1160 mm
Length: 3070 mm
Thickness: 40 mm
Quantity: 28 pieces
Production Weight
Gross production: ~11.0 MT
Net delivery weight: ~10.6 MT
Production Process
1. Raw Material & Melting
Controlled melting using induction furnace
Tin (Sn) adjusted to ~1.0% for marine performance
2. Rolling & Heat Treatment
Hot rolling for large-size plates
Intermediate annealing
Final stress-relief annealing
This step is critical because:
👉 Tube plates require stable internal structure for drilling thousands of holes
3. Surface Preparation
Before delivery:
Both sides were milled (not just raw plate)
Surface oxide layer removed
Edges trimmed
This reduces:
Tool wear during machining
Surface defects during drilling
Inspection & Quality Control
Inspection Timing
During production (in-process check)
Before dispatch (final inspection)
Actual Inspection Focus
Chemical composition (Sn content confirmation)
Ultrasonic testing for internal defects
Flatness measurement
Visual inspection
Observed Results
No internal defects detected by UT
Flatness within acceptable fabrication range
Surface condition suitable for machining
All results were included in:
EN 10204 3.1 certificate
Internal QC reports
Packing & Shipment
Packing Method
Wooden pallets (fumigated)
Each plate separated with soft protection
Moisture-proof film wrapping
Shipment
Loading Port: Shanghai
Destination: Jebel Ali Port, UAE
Containers: 2 × 20GP
Timeline
Production: ~3 weeks
Packing & booking: 1 week
Sea transit: ~3 weeks
✔ Total: ~6–7 weeks door-to-port
After Delivery
About 3 weeks after arrival, the client updated us during follow-up:
Tube drilling completed without abnormal tool wear
No leakage issues reported after assembly
Material consistency acceptable across all plates
They also mentioned:
"Compared with previous supply, machining stability is improved."
Why This Case Is Important
This case reflects a typical real scenario in Middle East projects:
Not a "perfect spec from day one" → drawings evolve
Real concern: drilling performance, not just chemistry
Key success factor: internal quality + flatness, not just standard compliance
Application Context
The tube plates were used in:
Seawater heat exchangers
District cooling systems
Industrial cooling loops
These systems require:
Long-term corrosion resistance
Stable mechanical performance
Reliable machining behavior
FAQ
1. Why do tube plates fail during drilling?
Usually due to internal porosity or uneven structure from poor rolling or casting.
2. Is C46400 suitable for seawater cooling systems?
Yes, it is widely used due to its tin content and corrosion resistance.
3. Do you supply machined tube plates or raw plates?
We can supply raw, milled, or fully machined based on drawings.
4. What is your typical delivery time to UAE?
Around 6–7 weeks including production and sea freight.
Contact Us
If you are sourcing Naval Brass Tube Plates (C46400 / SB171) for:
Heat exchangers
Cooling systems
Marine applications
We can support with stable quality and reliable delivery.
📩 Send your RFQ or drawings for a quick quote.
+8615769214734
office@dongmjd.com
