Copper Coils

Copper coils are manufactured based on the requirements of specifications under JIS H3300 . For JIS H3300, it is a standard that specifies expanded copper and copper alloy seamless pipes and tubes, having a round section. Copper coils are lightweight , high corrosion resistant , suitable for heat exchanger , and minimize the need of joints .

The hardness and strength of coil are defined by its temper , which is drawn and annealed. Drawn temper are refers to hard temper while annealed refers to soft temper. Copper coil is a soft temper pancake coil, where it can be easily bent by hand pressure. However a suitable bending tools are recommended for bending purpose. The ease of bending makes copper coils are economical as it does not require a lot of joints.

Copper Coils

Under JIS H3300, the tensile strength for copper coil is 245 N/mm² - 324 N/mm². For Chuan Kok’s copper coils, it contains a minimum 99.90% of copper (CU) and range of phosphorus in 0.015% - 0.040%. This copper material chemical combination also known as phosphorus deoxidized copper. Deoxidized copper with phosphorus is to reduce the cuprous oxide and remove porosity by acting as oxygen removal during the manufacturing process.

Copper Coils

The temper of the copper coil determines its strength and hardness. In the pipe industry, temper may be classified into two categories: Annealed tempered , also known as soft tube, and drawn tempered , also known as hard tube.

In our product range, we offer annealed tempered which is soft-typed copper coils. During installation, soft tempered copper coils are commonly connected using flare type fittings and compression fittings. Capillary fittings are also commonly used by users to join copper coils by soldering, brazing, or welding.

Hard coils are a totally opposite for copper coils. They are commonly referred to as pipes and are well-known for their use in water lines. The hardening process that the stiff copper goes through makes it extremely difficult to bend, unless the heating procedure is repeated to soften it. By doing so, bending is possible.

Copper coils and tubes are terms that can be used interchangeably. However, when it comes to measurements and dimensions, the two phrases have distinct connotations for marine engineers. Some of the distinctions between copper coils and tubes are as follows:

The copper coil outer diameter (OD) is measured by Inches and MM. For Inches OD, it is available from 1/4"OD to 7/8"OD. While for MM OD, the outer diameter size is available from 6MM to 15MM. The Table below illustrates the OD tolerance under standard JIS H3300.

For copper coil thickness, it also available in two measurements: MM and Standard Gauges. For MM thickness , it is available in 0.9MM, 1.2MM, and 1.5MM. For Standard Gauges thickness , it is available in SWG or BWG. Below table illustrates the Standard Gauges thickness.

Capillary fittings have a socket-type end that can assist eliminate the tolerance gap between the copper coil and the connecting fittings. When both the copper coil and the capillary fittings have been cleaned and fluxed, they can produce a narrow even gap when assembled. Hence, the forces of adhesion and cohesion cause the melted solder to stick together when the solder is heated until it melts.

• Step 1: Measure and cut the copper coil to the required length, being careful not to cut it too short or too long in order to achieve a proper connection.
• Step 2: Sandpaper or steel wool will be used to clean the coil and capillary fittings. Once cleaned, an adequate flux will be applied, resulting in a thin layer on the mating surfaces. This is done to keep dust and debris out of the capillary gap. The joint is ready for heating after the copper coil and capillary fittings have been fluxed.
• Step 3: Heat the joint. The solder is brought to the area of the capillary gap to be heated. If the solder does not melt, keep heating until it does. All around the coil, the capillary gap should be filled with enough solder. Please be cautious and avoid melting excessive solder into the capillary gap when soldering.
• Step 4: Here comes the cooling process. The heated solder is allowed to entirely cool down before solidifying and completely closing the capillary gap.
• Step 5: Finally, wipe the tube's outer surface with a cloth to remove any excess flux.