High Purity (DI, Lab): Stainless Steel Pipe

High Purity piping systems exist in many applications from electronic manufacturing to food...

Stainless steel defines a class of ferrous metals with high alloy content to enhance certain...

Benefit of Material to Systems Application

Cleanliness and corrosion resistance is imperative in high purity systems, and stainless steel pipe can provide these qualities. Some of the other benefits stainless steel brings to high purity systems are erosion resistance, oxidation resistance and temperature resistance. Stainless steel pipe is a traditional piping material for high purity applications.

Although it is often more expensive than other piping materials, superior life cycle costs make stainless steel pipe an attractive material. Therefore, in many cases it is the most cost efficient solution. However, in electrically sensitive applications that use de-ionized (DI) water, non-metallic pipe such as polyvinylidene fluoride (PVDF) may be a better choice due to its non-conductive qualities.

System Application and Material Usage

Stainless steel piping systems are used to supply high purity water to processes including the production of semiconductors and specialty polymer resins, and also for sterile environments such as biotechnology and life science laboratories. Special techniques must be followed when installing and testing stainless steel piping systems for high purity applications. Specifications for cleanliness may require the welding operation to be performed in a Class 100 or Class 1000 clean room environment.

Cleaning methods after fabrication and prior to welding may include a DI water rinse as well as blowing swabs through the pipe for mechanical cleaning. In addition, a hot argon purge may be required for moisture removal. An argon purge may also be required during the welding process itself.

For testing, use argon to pressurize the system to 1.5 times the working pressure for 24 hours. Additional testing may be required depending on the high purity application.

Stainless steel is the generic name for a number of different steels used primarily because of their corrosion resistant properties.  All stainless steels contain a varying percentage of chromium, molybdenum and nickel.  The most common "family" of stainless steel is austenitic, which includes the stainless steel pipes made to the specifications of ASTM A312 in Types 304/304L and 316/316L. Types 304/304L are for general corrosion applications, and types 316/316L have a higher corrosion resistance and may be required based upon an externally corrosive environment. The “L” designation means that the stainless steel contains less than 0.03% carbon. This is beneficial if the pipe needs to be welded.
Type 316L is almost always the stainless steel option for high purity systems.

Stainless steel pipe is generally available in diameters up to 36 inches with dimensions ranging from Schedule 5S to 160S with Schedule 5S and 10S being the most common. Schedule designations indicate the pressure capacity of the pipe. When specifying the Schedule of stainless steel pipe, an “S” is added after the Schedule number to differentiate stainless steel from other steel pipe. The system working pressure and pipe joining method will determine the required pipe wall thickness for each application.

An additional source for general information on stainless steel is http://www.stainless-steel-world.net/.

Manufacturers and Suppliers Participating in OPUS

F.W. Webb Company

F.W. Webb Company is a multi-faceted distributor of plumbing and heating, HVAC and controls,......
(click for details)


Ferguson specializes in providing PVF, Plumbing, HVAC and Related Specialty Products and......
(click for details)

Galloup Company

J.O. Galloup Company is a premier distributor of commercial and industrial piping products,......
(click for details)

Hajoca Corporation

Founded in 1858, the Hajoca Corporation is the largest privately owned wholesale distributor of......
(click for details)

Jomar Valve

Founded in 1966 by former Navy Commander Joseph Martin, Jomar Valve set out to change the way......
(click for details)

Metraflex Company

For over 55years Metraflex has met the needs of the contractor. The MetraLoop, a flexible pipe......
(click for details)


MORSCO is a leading U.S. distributor of commercial and residential plumbing, HVAC, and PVF, with......
(click for details)

Team Industries, Inc.

Team Industries, Inc. offers a 3000# Generation III and 3000# Generation IV (hydraulically......
(click for details)

The Commonwealth Group

The Commonwealth Group is the industry’s newest, 100-percent member owned, $8.5......
(click for details)

Tri Tool Inc.

Tri Tool Inc. designs and manufactures cutting and prepping tools for pipe and tube from .12 to......
(click for details)


Founded in 1899, Viega manufactures and distributes the highest quality plumbing, heating and......
(click for details)

Weldbend Corporation

Weldbend Corporation is a manufacturer of carbon steel welding fittings and forged steel......
(click for details)


WinWholesale, Inc. is comprised of over 525 wholesale distribution locations. Along with Noland......
(click for details)

Applicable Joining Methods


Flanging maybe used for threaded or plane-end pipe. After a flange component is installed on the...
(click for details)


Grooved pipe joints consist of two grooved pipe ends (typically roll grooved) connected with a...
(click for details)


A connection in which an internal threaded fitting and an external threaded piece of pipe or...
(click for details)


Welding is generally defined as the act of joining together two or more components by heating...
(click for details)