piping

For other uses, see Piping (sewing), Bagpiping or Pipe.

Large-scale piping system in an HVAC mechanical room

Within industry, piping is a system of pipes used to convey fluids (liquids and gases) from one location to another. The engineering discipline of piping design studies the efficient transport of fluid.^[1][2]

Industrial process piping (and accompanying in-line components) can be manufactured from wood, fiberglass, glass, steel, aluminum, plastic, copper, and concrete. The in-line components, known as fittings, valves, and other devices, typically sense and control the pressure, flow rate and temperature of the transmitted fluid, and usually are included in the field of Piping Design (or Piping Engineering). Piping systems are documented in piping and instrumentation diagrams (P&IDs). If necessary, pipes can be cleaned by the tube cleaning process.

"Piping" sometimes refers to Piping Design or the performance of the actual layout of the physical piping within a process plant or commercial building. In earlier days, this was sometimes called Drafting, Technical drawing, Engineering Drawing, and Design but is commonly performed by Designers who have learned to used automated computer aided drawing/computer aided design (CAD) software.

Plumbing is a piping system that most people are familiar with, as it constitutes the form of fluid transportation that is used to provide potable water and fuels to their homes and business. Plumbing pipes also remove waste in the form of sewage, and allow venting of sewage gases to the outdoors. Fire sprinkler systems also use piping, and may transport potable or nonpotable water, or other fire-suppression fluids.

Piping also has many other industrial applications, which are crucial for moving raw and semi-processed fluids for refining into more useful products. Some of the more exotic materials of construction are Inconel, Titanium, chrome-moly and various other steel alloys.

Pipe stress analysis

Process piping and power piping are typically checked by pipe stress engineers to verify that the routing, nozzle loads, hangers, and supports are properly placed and selected such that allowable pipe stress is not exceeded under different situation such as sustain, operating, hydro test etc as per the ASME or any other legislative code and local government standards, Here it is necessary to check the occasional cases such as earthquake, high wind or special vibration, water hammer.^[3][4] This checking is usually done with the assistance of a (finite element) pipe stress analysis program such as Caesar II, ROHR2, CAEPIPE and AUTOPIPE.

Wooden piping history

Early wooden pipes were constructed out of logs that had a large hole bored lengthwise through the center. Later wooden pipes were constructed with staves and hoops similar to wooden barrel construction. Stave pipes have the advantage that they are easily transport as a compact pile of parts on a wagon and then assembled as a hollow structure at the job site. Wooden pipes were especially popular in mountain regions where transport of heavy iron or concrete pipes would have been difficult.

Wooden pipes were easier to maintain than metal, because the wood did not expand or contract as much as metal and so consequently expansion joints and bends were not required. The thickness of wood afforded some insulating properties to the pipes which helped prevent freezing as compared to metal pipes. Wood used for water pipes also does not rot very easily.

In the Western United States where redwood was used for pipe construction, it was found that redwood had "peculiar properties" that protected it from weathering, acids, insects, and fungus growths. Redwood pipes stayed smooth and clean indefinitely while iron pipe by comparison would rapidly begin to scale and corrode and could eventually plug itself up with the corrosion. ^[5]

See also

• Firestop
• Hydraulic machinery
• Hydrogen piping
• Hydrostatic test
• Pipe network analysis
• Piping and plumbing fittings
  • Coupling (piping)
  • Elbow (piping)
  • Nipple (plumbing)
  • Pipe cap
  • Street elbow
  • Union (plumbing)
  • Valve
  • Victaulic
• Plastic Pressure Pipe Systems
• Riser clamp
• Thermal insulation
• Gasket

References

Further reading

• ASME B31.3 Process Piping Guide, Revision 1 from Los Alamos National Laboratory Engineering Standards Manual OST220-03-01-ESM
• Seismic Design and Retrofit of Piping Systems, July 2002 from American Lifelines Alliance website
• Engineering and Design, Liquid Process Piping U.S. Army Corps of Engineers, EM 1110-l-4008, May 1999

External links

Wikimedia Commons has media related to: Piping

• Building services piping links at the Open Directory Project