IUSA Copper Tube System Installation and Troubleshooting Guide

IUSA Copper Tube System Installation and Troubleshooting Guide

IUSA Cambridge Lee is a leading global copper tube manufacturer, with products covering refrigeration air conditioning (ACR) pipes, water pipes (Type L/K/M), and medical gas pipes. Copper pipes are widely used in HVAC, water supply and drainage, fire protection, medical gas supply and other fields due to their excellent thermal conductivity, corrosion resistance and processability. However, improper selection, installation, or maintenance can lead to leakage, blockage, corrosion, and even system failure. This article is based on the IUSA copper tube product technical manual and combines practical application experience to compile a set of fault diagnosis and prevention guidelines suitable for on-site engineers.

Overview of Product Series and Key Selection Points

2.1 ACR Standard Pipe (ASTM B280)

Features: Degreasing, dehydration, nitrogen filling and covering to prevent internal oxidation. Suitable for air conditioning refrigeration and freezing equipment.

Common faults: Residual oil or oxide in the pipe can cause blockage of the throttle valve and damage to the compressor.

Selection tip: Be sure to confirm that the pipe end cap is intact and undamaged, and avoid opening the original packaging before installation.

2.2 ACR Perform Pipe (ASTM B743)

Features: Higher hardness options (H58, O50, O60), suitable for occasions that require higher mechanical strength.

Common malfunction: Cracks occur during bending, especially in the hard state (H58) and when the radius is too small.

Selection tip: Choose the appropriate annealing state based on the bending radius (soft O60 is suitable for large curvature bending).

2.3 ACR Eco Tube

Features: Economical soft copper tube, nitrogen protection, suitable for ordinary refrigeration and air conditioning pipelines.

Common faults: Thin wall thickness (such as 1/4 "wall thickness of only 0.51mm), susceptible to external force flattening or corrosion perforation.

Selection tip: In vibration or corrosive environments, thicker walled ACR Standard or Perform series should be selected.

2.4 Water Pipe Series (Type L, K, M, ASTM B88)

Type K: thickest wall, high pressure resistance, suitable for underground pipelines, fire protection, and high-voltage systems.

Type L: Medium wall thickness, most commonly used (blue label), suitable for general water supply and hot water.

Type M: thinnest wall (marked in red), suitable for low-pressure indoor water supply.

Common faults: Insufficient wall thickness selection leads to long-term pressure rupture or corrosion perforation.

Selection tip: Type K is preferred for buried or humid environments; Use an L-shaped hot water circulation system and pay attention to expansion compensation.

2.5 Medical Gas Tube (ASTM B819, Type L/K Clean Degreasing)

Features: Strict cleanliness requirements, compliant with CGA G4.1 and NFPA99. There is no grease or particles inside the tube.

Common malfunction: Introducing pollutants during installation, resulting in a decrease in medical gas purity or valve jamming.

Selection tip: Special cutting tools must be used and the end caps must be kept closed before installation.

Common fault phenomena and cause analysis

3.1 Leakage of brazed joints

Phenomenon: When the system maintains pressure, the pressure drops and there are visible moisture or bubbles at the welding site.

Possible reasons:

Unclean pipe ends or fittings, with oxides or grease obstructing the flow of solder.

Uneven heating and incomplete penetration of solder.

Using unqualified brazing or soldering materials (containing corrosive components).

The clearance between the pipe diameters is too large or too small.

Troubleshooting steps:

Use soap water or an electronic leak detector to confirm the leak point.

Cut open the leakage joint for observation: If the solder only forms rounded corners on the surface and the interior is not filled, it indicates insufficient heating or low solder volume.

Check whether the cutting of the pipe end is smooth and whether the deburring is thorough.

3.2 Internal blockage (refrigeration system)

Phenomenon: High exhaust temperature of compressor, ice blockage or dirty blockage of expansion valve.

Possible reasons:

During brazing, nitrogen protection was not used, resulting in the detachment of oxide scale (black copper) on the inner wall of the tube.

Residual moisture, oil stains, or metal shavings inside the pipeline.

During storage or installation, the pipe end is not sealed and dust or moisture enters.

Troubleshooting steps:

Open the pipeline and check the color of the inner wall - black or green oxide layer indicates high-temperature oxidation.

Wipe the inner wall of the tube with a white cloth. If there is black powder or oil stain, it needs to be thoroughly cleaned or replaced.

Confirm whether nitrogen gas (flow rate 0.5-1.0 m ³/h) is continuously introduced during installation and maintained at a slight positive pressure.

3.3 Cracking or flattening of bent parts

Phenomenon: Leakage of refrigerant and decrease in flow rate.

Possible reasons:

Use hard (H58) copper tube for small radius bending.

Failure to use a pipe bender during bending resulted in wrinkles or cracks due to manual bending.