What is a Capillary Tubing and how does it work?

Precision Capillary Tubing: 

Learn how small-diameter stainless steel and alloy tubes work for precise fluid control in applications from HVAC and medical devices to industrial oil & gas control lines.

Capillary tubing is a specialized, seamless stainless steel coiled product with a very small inner diameter and uniform wall thickness, typically ranging from 0.1mm to 2mm. It is commonly produced from stainless steel grades like 304, 316L, 2205, and 2507, or from nickel-based alloys. These materials offer excellent corrosion, high-pressure, and high-temperature resistance, ensuring stable, long-term performance in complex environments.

Capillary tubing works through two main mechanisms. Firstly, capillary action allows liquids to migrate automatically without external power. This is especially valuable in medical and instrumentation fields. Secondly, the small diameter creates significant flow resistance, enabling precise flow control and measurement within fluid systems.

In the HVAC&R industry, it controls refrigerant flow for efficient heat exchange. In scientific instruments, such as gas chromatographs, it handles sample delivery, which is fundamental to accurate analysis. In medical devices, it is used to create minimally invasive surgical tools and drug delivery systems.

For more demanding industries like oil & gas, geothermal, and shipbuilding, capillary tubing serves as a control line. It performs the critical task of transporting high-pressure fluids and chemical agents.

MTSCO, through its affiliated factory Siri Tubing, specializes in producing high-performance capillary tubing for these harsh environments. We ensure our products operate stably over the long term, even in deep-sea and underground conditions. Our capillary tubing products are available in single coils up to 50,000 feet in length. Each product undergoes 100% high-pressure testing, withstanding pressures up to 15,000 psi. This provides global clients with the highest standard of tubing support for their precision control systems.