Stainless Steel Needle Tube T.I.G Welded and Seamless TP304 TP316L Capillary

Stainless Steel Needle Tube T.I.G Welded and Seamless TP304 TP316L Capillary

Medical Tubing is manufactured using 304, 304L and 316L Stainless Steel. 304 Stainless Steel has a relatively low carbon content (0.08 percent maximum), and it resists corrosion better than 302 Stainless Steel. Its counterpart, 304L Stainless Steel, has an even lower carbon content (0.04 percent maximum), and offers similar corrosion resistance. However, 304L also offers high resistance to intergranular corrosion after welding. 316L is sometimes used in Medical instrumentation and has a lower carbon content than 316 Stainless. 316L is used in areas where superior corrosion resistance is required.

A capillary tube is a very thin tube, typically with an internal diameter ranging from 0.3 mm to 2 mm. It’s used widely in mechanical, chemical, and medical applications due to its ability to precisely control and regulate fluid flow.

What is a Capillary Tube?

A capillary tube works on the principle of capillary action, where liquid can flow through narrow spaces without the assistance of external forces (like gravity). This is primarily due to surface tension, adhesive and cohesive forces.

Common Usage of Capillary Tubes:

Refrigeration and Air Conditioning:

Acts as an expansion device that reduces refrigerant pressure from the condenser to the evaporator.

Simple, cost-effective alternative to expansion valves in small systems.

Medical Applications:

Used to collect blood samples (especially in pediatric and point-of-care settings).

Found in devices like hematocrit tubes or micro-pipettes.

Chemical and Laboratory Use:

Used in chromatography, sample transfer, or flow control.

In precision dosing and microfluidic systems.

Fuel Systems and Lubrication:

Controls small, consistent flow of fuel or oil.

Production Methods of Capillary Tubes:

Capillary tubes are typically made from metals (like copper, stainless steel) .

For Metal (e.g., Copper Capillary Tubes):

1. Extrusion:

   A metal billet is forced through a die to create a long, narrow tube.

2. Drawing:

   The extruded tube is then pulled through progressively smaller dies to reduce the diameter.Annealing may be used between draws to soften the metal.

3. Coiling:

   Tubes are coiled into spirals or straight lengths depending on usage.

Key Characteristics

• Inner Diameter (ID): Critical to control fluid flow.

• Length: Affects pressure drop.

• Material: Depends on corrosion resistance, flexibility, and thermal conductivity.