Stainless steel tubing is used for many applications that require resistance to high pressures, high temperatures, and corrosive environments.  These include, but are not limited to: petrochemical, gas, nuclear, food and beverage, and chemical plants.  Various wall thicknesses are available to suit a range of pressure requirements, and several different finishes are available to achieve the desired aesthetic.

MSI is a tubing distributor, offering tubing in carbon, stainless, along with several special alloys. With tubing diameters ranging from 1/8” to 2"", MSI can provide the tubing required for virturally any project.

STAINLESS STEEL TUBING TYPE

There are 2 different types of stainless steel tubing: straight length and continuous coiled stainless steel tubing. The straight length stainless steel tubing typically comes in 20-foot section, but special lengths such as 30 or 40 feet are available upon request.

TUBING DIAMETER & WALL THICKNESS

The primary distinguishing element between stainless pipe and stainless steel tubing is the dimensions to which they are formed.  While pipe follows Nominal Pipe Sizes (NPS) and pipe schedules, stainless steel tubing has exact dimensions.  For instance, a ½” pipe has an outside diameter of 0.840", regardless of the wall thickness (schedule).  A ½” tube, on the other hand, has an outside diameter of ½”, regardless of the wall thickness. 

The tubing burst chart will determine that right wall thickness based on your working pressure. For instance, if you need 1/4” stainless steel tubing suitable to hold a working pressure of 8000psi you will need to use .065 wall thickness. The tubing burst chart shows a bursting pressure of 39,000 psi then you divide this by the factory safety of 4 giving you a result of 9,750 psi which is the maximum allowable working pressure.  The diagram below shows the dimensions of a 1/4" X .065" tube, where the outside diameter is 1/4" and the wall thickness is .065".   Unlike pipe, which has nominal outside diameter sizes, stainless steel tubing outside diameters are exact.  Also, in contrast to pipe, which specifies wall thickness via pipe schedule, stainless steel tubing wall thickness is specified in inches.

STAINLESS STEEL TUBING SURFACE FINISH

There are 3 surface finishes that are well known in the industry: Bright Annealed, Polished and Annealed and Pickled. The Bright Annealed stainless steel tubing, commonly referred to as BA finish, is cold rolled using highly polished rolls in contact with the steel surface, making it both smooth and bright.  This stainless steel tubing is then polished to 400 grit and offers a more accurate thickness than other available finishes.  This finish is generally regarded as the highest quality finish available.

Tubing

The Polished stainless steel tubing, commonly referred as to PT finish, is mechanically polished and brushed using abrasive materials that cut the surface of the steel to a slight degree. This polishing is typically done to 240 grit.

The Annealed and Pickled finish, more commonly referred to as Mill Finish, is the basic supply condition for all stainless steel products. In order to maximize resistance to corrosion mill finishes are acid cleaned (pickled) to remove scale formed during the hot rolling and annealing process.  Mill finish is generally less expensive than polished stainless steel tubing, as it follows the same steps of production as PT, without the additional polishing process.

About Us

MSI Supply is a Houston, TX based full-line distributor of pipe, valves, fittings, flanges, stud bolts, gaskets, and fasteners, serving price-conscious customers who desire quick deliveries and consolidation of their material needs. With a large inventory of carbon and stainless pipe, cast and forged steel valves, tubing, and the thousands of fittings and fasteners required to put it all together, MSI can meet the needs of virtually any piping, fastener, or instrumentation project.

Also MSI is a full-line distributor of gate valves, globe valves, and check valves, with a large portfolio of: carbon steel, stainless steel, and exotic alloy. End connections for each gate valve, globe valve, and check valve include: flanged, threaded, and socket weld. With sizes ranging from 1/4” to 36", and pressure classes ranging from 150# - 2500#, MSI can supply the gate valves, globe valves, and check valves to meet the requirements of virtually any piping project.