Tubing (material)
From Wikipedia, the free encyclopedia
- For structural tubing, see hollow structural section.
Image:Plastic tubing.jpg Tubing refers to a flexible hose or pipe used in plumbing, irrigation, and other industries. Tubing may be made of polyvinyl chloride (PVC), polyethylene (PE), copper, or other material. Tubing is usually supplied in rolls compared to rigid pipe which is sold in straight lengths called joints or sticks. Tubing is usually measured by its outside diameter, while pipe was historically measured by its inside diameter.
Metal tubing differs from metal pipe in the way it is dimensioned. Tubing is specified by OD and wall thickness, whereas pipe is specified by a non-dimensional nominal pipe size (NPS) and a schedule (SCH). Metal tubing generally has much thinner wall than pipe and can be bent, although both of these depend on the specific application.
[edit] Manufacture
Three methods exist for tubing manufacture: seamless, as-welded, and drawn-over-mandrel (DOM).
[edit] Standards
Many standards exist for tube manufacture. Some of the most common ones are as follows:
- ASTM A213 seamless stainless steel pressure tubing
- ASTM A269 welded stainless steel pressure tubing
- ASTM A270 seamless and welded stainless steel sanitary tubing
- ASTM A511 seamless stainless steel mechanical tubing
- ASTM A554 welded stainless steel mechanical tubing
ASTM material specifications generally cover a variety of grades or types that indicate a specific material composition. Some of the most commonly used are:
- TP 304
- TP 316
- MT 304
in Hydrogen installations copper and stainless steel tubing must be factory pre-cleaned (ASTM B 280) or certified as instrument grade. Tubing quality and source must be documented [1].
