Hard-drawn capillary tubes
First of all, hard-drawn tubing can be specified for restrictor applications requiring controlled dimensions and a defined straightness or form.
Review selection details →Product overview
Copper capillary tubes for controlled refrigerant flow
In addition, S K Metal supplies copper capillary tubes for buyers who need tightly controlled bore dimensions, clean internal surfaces and repeatable flow characteristics.
Capillary tubing can act as a fixed restriction in compatible refrigeration and air-conditioning circuits. However, flow depends on internal diameter, length, refrigerant, operating conditions and cleanliness. Therefore, buyers should provide the equipment design or approved capillary specification instead of selecting a tube from outside diameter alone.
See what to include in your capillary-tube enquiry
Tube formats and supply options
Choose copper capillary tubes for the application
First, confirm the functional bore and length. Then verify OD, wall thickness, temper, cleanliness and supply form.
Annealed capillary coils
In addition, annealed coil formats support installations or production processes that require flexible routing.
Request coil availability →Straight capillary lengths
However, straight cut lengths may be preferable where handling, assembly or repeat cut size is controlled.
Check length options →Refrigeration capillary tubing
Moreover, clean small-bore tubes can serve as fixed restrictions in approved refrigeration circuits.
Send your flow requirement →Precision instrument tubing
Furthermore, selected capillary dimensions may suit compatible instrumentation and small-volume transfer applications.
Discuss precision requirements →Cut and coiled supply
Finally, supply form can be reviewed against required length, coil diameter, end condition and packaging.
Send supply details →Specification guide
How to specify copper capillary tubing
Therefore, a complete dimensional and functional specification helps avoid incorrect bore size, flow performance or supply condition.
- Outside diameter
- First of all, provide the required OD and dimensional tolerance in millimetres or inches.
- Inside diameter
- Next, state the bore and tolerance because flow resistance is highly sensitive to internal diameter.
- Wall thickness
- Also confirm the nominal wall and permitted variation against the approved design.
- Material & temper
- Moreover, identify copper grade, hard-drawn or annealed temper and applicable product standard.
- Length & form
- In addition, specify straight length, coil length, coil diameter, cut tolerance and end condition.
- Application data
- Finally, provide refrigerant or medium, target flow information, operating pressure and temperature where applicable.
- Quantity & delivery
- Therefore, include total length or piece count, packaging, delivery city, required date and documentation needs.
Important: Capillary flow is affected by bore, length, inlet conditions, refrigerant and system design. Therefore, the equipment designer should approve the capillary specification before purchase.
Applications
Applications of copper capillary tubes
Because requirements differ, the correct tube depends on bore, length, cleanliness, pressure, temperature and system design.
Domestic refrigeration
For example, capillary tubes can meter refrigerant in compatible refrigerators and compact cooling circuits.
Air-conditioning equipment
Moreover, selected capillary restrictions may be used in small AC systems designed for fixed operating conditions.
Commercial cooling
In addition, approved tubing can support refrigerated displays, cabinets and purpose-built cooling equipment.
OEM assemblies
Furthermore, cut lengths or coils can feed repeat manufacturing where dimensions and cleanliness are controlled.
Instrumentation
However, instrument applications require confirmation of bore, medium, pressure, cleanliness and connection method.
Laboratory equipment
Therefore, only application-approved dimensions and materials should be used for precision laboratory flow paths.
Quality and documentation
Verify capillary dimensions and documents
Before ordering, ask for documentation applicable to the exact tube and source being quoted. In addition, engineers can review the ASTM copper standards catalogue, including the current standard applicable to hard-drawn copper capillary tube for restrictor applications.
Discuss your material requirement →- OD, ID and wall-thickness verification
- Bore continuity, internal cleanliness and end-condition checks
- Temper, coil form and cut-length confirmation
- Material documents when included in the quotation
- Protective packaging and product identification requirements
Ordering checklist
How to order copper capillary tubes
For an accurate quotation, send the approved tube schedule or equipment specification when several bores, lengths or forms are required.
State OD and ID
First of all, provide outside diameter, bore and tolerances in one consistent unit.
Add wall and length
Next, list wall thickness, straight or coil length, cut tolerance and end condition.
Define material condition
Then provide copper grade, temper, cleanliness and applicable product standard.
Describe the application
In addition, state refrigerant or medium, operating conditions and approved flow or equipment reference.
Confirm quantity and delivery
Finally, include total length or pieces, packaging, delivery location, schedule and documentation requirements.
Frequently asked questions
Copper capillary tubes FAQs
What information is needed for a capillary tube quotation?
For an accurate quotation, provide OD, ID, wall thickness, tolerances, material, temper, length or coil form, quantity and delivery location.
How does a copper capillary tube control refrigerant?
In general, its small bore and selected length create a pressure drop that meters flow. However, actual performance depends on refrigerant and system conditions.
Is outside diameter enough to select a capillary tube?
No. Instead, the design must define inside diameter, length, wall, tolerances and operating requirement because bore strongly affects flow.
Can capillary tubes be supplied in coils?
Yes, subject to size and availability. Nevertheless, specify temper, coil length, coil diameter, packaging and acceptable handling condition.
Why is internal cleanliness important?
Because the bore is small, contamination or deformation can alter or obstruct flow. Therefore, end protection and clean handling are important.
Are inspection documents available?
However, document availability depends on the product and order. Consequently, state dimensional, material or inspection requirements before quotation.
Request a quotation
Send your capillary tube size schedule
To begin, include OD, ID, wall thickness, material, temper, length or coil form, quantity and delivery location. Afterward, S K Metal will review availability and the applicable commercial and technical details.
Send your requirement