A pipe is a tubular part or hollow cylinder, usually but not necessarily a circular cross section, used primarily to carry flowable substances - liquids and gases (liquids), pulp, powder and small solid masses. It can also be used for structural applications; Hollow pipe is much harder per unit weight than solid members.
In general use the words pipe and tubes are usually interchangeable, but in industry and engineering, the terms are uniquely defined. Depending on the standards applicable to it manufactured, the pipe is generally determined by a nominal diameter with a constant outer diameter (OD) and a timetable that determines the thickness. The tube is most often determined by OD and wall thickness, but can be determined by two OD, inner diameter (ID), and wall thickness. Pipes are generally made for one of several international and national industry standards. While the same standards exist for tubing certain industrial applications, tubes are often made for special sizes and wider diameter and tolerance ranges. Many industry and government standards exist for the production of pipes and tubes. The term "tube" is also commonly used for non-cylindrical parts, ie, square or rectangular pipes. In general, "pipes" are standard in size for various liquids, while "tubes" tend to insert long hollow objects.
Both "pipe" and "tube" imply a degree of rigidity and timelessness, while the hose (hosepipe) is usually portable and flexible. Pipe assemblies are almost always built using fittings such as elbows, tees, and so on, while tubes can be molded or bent into custom configurations. For materials that are not flexible, can not be formed, or where the construction is governed by code or standard, the tube assembly is also constructed using tube fittings.
Video Pipe (fluid conveyance)
Usage
- Pipe
- Tap water
- Pipeline transporting gas or liquids remotely
- Compressed air system
- Pipe bomb
- Casing for concrete pile used in construction project
- High temperature or high pressure manufacturing process
- Petroleum industry:
- Oil well cover
- Oil refinery equipment
- Delivery of liquids, either in gaseous or liquid form, at the processing plant from one point to another in the process
- Bulk solid delivery, in the food factory or process from one point to another in the process
- Construction of high pressure storage vessels (note that large pressure vessels are built from plates, not pipes because of the thickness and size of the walls).
In addition, pipes are used for many purposes that do not involve fluid delivery. Handrails, scaffolds and supporting structures are often constructed from structural pipes, especially in industrial environments.
Maps Pipe (fluid conveyance)
Producing
There are three processes of making metal pipes. Centrifugal casting of hot alloys is one of the most prominent processes. Ductile iron pipes are generally made in such a way. Seamless (SMLS) pipes are formed by drawing a solid billet above the piercing stem to create a hollow shell. Because the manufacturing process does not include welding, smooth pipes are considered stronger and more reliable. Historically, seamless pipes are regarded as better restraining pressures than other types, and are often more available than welded pipes.
Progress since the 1970s in materials, process control, and non-destructive testing, enables precisely welded pipes to replace seamlessly in many applications. The welded pipe is formed by rolling plates and welding seams (usually by electric resistance welding ("ERW"), or Electric Fusion Welding ("EFW")). Flash welding can be removed from the inner and outer surfaces using a scarfing blade. The weld zone can also be heat treated to make the stitches less visible. Welded pipes often have tighter dimensional tolerances than smooth ones, and can be less expensive to produce.
There are a number of processes that can be used to generate ERW pipes. Each of these processes leads to the smelting or incorporation of steel components into the pipe. Electric current is passed through surfaces to be welded together; as the component is welded together to withstand the electric current, heat is generated which forms the weld. A liquid metal pool is formed in which two surfaces are connected as a strong electric current is passed through the metal; pools of molten metal form a weld that binds two components together.
ERW pipes are made of longitudinal steel welding. The welding process for ERW pipes is continuous, compared to welding different parts at intervals. The ERW process uses steel rolls as raw materials.
High Frequency Induction Technology (HFI) welding process is used to manufacture ERW pipes. In this process, the current for welding the pipe is applied by means of induction coils around the tube. HFI is generally considered to be technically superior to "regular" ERWs when creating pipelines for critical applications, such as for energy sector use, in addition to other uses in pipeline applications, as well as for casing and tubing.
Large diameter pipes (25 cm (10 in) or larger) may be ERW, EFW or Submerged Arc Welded ("SAW") pipes. There are two technologies that can be used to produce steel pipes of greater size than steel pipes that can be produced with a smooth and ERW process. The two types of pipes generated through this technology are longitudinal arc-lased welding (LSAW) and spiral-soaked welding pipes (SSAW). LSAW is made by warping and welding of wide steel plates and most commonly used in oil and gas industry applications. Due to the high cost, the LSAW pipes are rarely used in low value non-energy applications such as pipelines. SSAW pipes are manufactured by spiral (helicoidal) steel welding coils and have a cost advantage over the LSAW pipeline, because the process uses coils rather than steel plates. Thus, in applications where spiral welds are acceptable, SSAW pipes can be preferred over LSAW pipes. Both the LSAW pipes and SSAW pipes compete with ERW pipes and seamless pipes in the 16 "-24" diameter range.
Tubing for flow, either metal or plastic, is generally extruded.
Materials
Pipes are made of various types of materials including ceramics, glass, fiberglass, many metals, concrete and plastics. In the past, wood and tin (Latin black tin , from which came the word 'pipe') is commonly used.
Usually metallic pipes are made of steel or iron, such as unfinished steel, black (lacquer), carbon steel, stainless steels, galvanized steel, brass, and ductile iron. Iron-based piping is subject to corrosion when used in high oxygenated water streams. An aluminum tube or tube may be used if the iron does not match the service fluid or if the weight is of concern; aluminum is also used for heat transfer tubing as in the refrigerant system. Popular copper pipes for domestic (potable) water pipe systems; copper can be used where desired heat transfer (ie radiator or heat exchanger). Inconel, moly chrome, and titanium alloy steel are used in high temperature and piping pressure in process and power facilities. When determining the alloy for a new process, known issues about creep and sensitization effects must be taken into account.
Lead piping is still found in domestic and other water distribution systems, but is no longer allowed for the installation of new water pipes due to its toxicity. Many building codes now require that the main pipe in a residential or institutional installation be replaced by a non-toxic pipe or that the interior of the tube is treated with phosphoric acid. According to a senior researcher and principal expert from the Canadian Environmental Law Association, "... there is no safe level of lead [for human exposure]". In 1991, the US EPA issued the Main Rule and Copper, it was a federal regulation that limited the concentration of lead and copper allowed in public drinking water, as well as the allowable amount of pipe corrosion that occurs due to the water itself. In the US it is estimated that 6.5 million pipe pipes installed before 1930 are still in use.
Plastic tubes are widely used because of their light weight, chemical resistance, non-corrosive properties, and ease of making connections. Plastic materials include polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), fiber-reinforced plastic (FRP), reinforced polymer mortar (RPMP), polypropylene (PP), polyethylene (PE), high density polyethylene (PEX) , polybutylene (PB), and acrylonitrile butadiene styrene (ABS), for example. In many countries, PVC pipes cover most of the pipe materials used in municipal applications for the distribution of drinking water and sewerage. Market researchers estimate total global revenues in excess of US $ 80 billion by 2019. In Europe, the market value will amount to approximately. EUR12.7 billion by 2020
Pipes can be made of concrete or ceramics, usually for low pressure applications such as gravity flow or drainage. Pipes for waste are still mostly made of clay or clay with vitrification. Reinforced concrete can be used for large diameter concrete pipes. This pipe material can be used in many types of construction, and is often used in the gravity flow transport of rainwater. Usually such pipes will have rechargeable bells or fittings trampled, with various sealing methods applied during installation.
Traceability and positive material identification (PMI)
When alloys for piping are forged, metallurgical tests are performed to determine the material composition with% of each chemical element in the piping, and the results are recorded in the Material Test Report (MTR). These tests can be used to prove that the alloy is compatible with various specifications (eg 316 SS). The test is stamped by the factory QA/QC department and can be used to track material back to the factory by users in the future, such as piping and fitting manufacturers. Maintaining traceability between alloy materials and associated MTRs is an important quality assurance issue. QA often requires hot numbers to be written on pipes. Precautions should also be taken to prevent the introduction of counterfeit materials. As reserves for etching/labeling of material identification in pipes, positive material identification (PMI) is performed using a handheld device; the device scans the pipe material using the x-ray fluorescence (XRF) wave and receives the analyzed response spectrographically.
Size
The size of the pipe can be confusing because the terminology may be related to the historical dimension. For example, half-inch iron pipes do not have dimensions that are half an inch. Initially, half-inch pipe does have an inner diameter of 0.5 inches (13 mm) - but it also has a thick wall. As technology increases, thin walls become possible, but the outer diameter remains the same so that it can mate with existing old pipes, increasing the inner diameter by more than half an inch. The history of copper pipe is similar. In the 1930s, the pipe was determined by its internal diameter and wall thickness 1 / 16 -inch (1.6 mm). As a result, 1 inch (25 mm) copper pipe has 1 1 / 8 -inch (28.58 mm ) outer diameter. The outer diameter is an important dimension for mating with completeness. Wall thickness in modern copper is usually thinner than 1 / 16 -inch (1.6 mm), so the internal diameter is only "nominal" not the control dimension. Newer pipe technology sometimes adopts the sizing system as its own. PVC Pipe using Nominal Pipe Size.
The pipe size is determined by a number of national and international standards, including API 5L, ANSI/ASME B36.10M and B36.19M in the US, BS 1600 and BS EN 10255 in the UK and Europe.
There are two common methods for setting the outer diameter of the pipe (OD). The North American method is called NPS ("Nominal Pipe Size") and is based on inches (also commonly referred to as NB ("Nominal Bore")). The European version is called DN ("Diametre Nominal"/"Nominal Diameter") and is based on millimeters. Determining the outside diameter allows the pipe of the same size to fit together no matter what wall thickness.
- For pipe sizes less than 14-inch NPS (DN 350), both methods provide a nominal value for a rounded OD and not the same as the actual OD. For example, 2 inches NPS and DN 50 are the same pipe, but the actual OD is 2.375 inches or 60.33 millimeters. The only way to get the real OD is to look at the reference table.
For the size of the 14-inch NPS pipe (DN 350) and larger the size of NPS is the actual diameter in inches and the DN size is equal to the time of NPS 25 (instead of 25.4) rounded off to a multiple of 50. For example, NPS 14 has an OD of 14 inches or 355.60 millimeters, and is equivalent to DN 350.
Because the outer diameter is set for the given pipe size, the inner diameter will vary depending on the thickness of the pipe wall. For example, 2 "Schedule 80 pipes have thicker walls and therefore the inside diameter is smaller than 2" Schedule 40 pipes.
Steel pipes have been produced for about 150 years. The size of the pipes used currently in PVC and galvanized originally designed many years ago for steel pipes. Number systems, such as Sch 40, 80, 160, are set long ago and look a bit strange. For example, the Sch 20 pipeline is even thinner than Sch 40, but the OD is the same. And while these pipes are based on the size of old steel pipes, there are other pipes, such as cpvc for hot water, using pipe sizes, inside and out, based on the standard size of old non-steel copper pipes.
Many different standards exist for pipe sizes, and their prevalence varies depending on the industry and geographic area. The pipe size determination generally includes two numbers; one showing the outside (OD) or nominal diameter, and the other showing the wall thickness. At the beginning of the 20th century, the American pipes were in deep diameter. This practice is abandoned to improve compatibility with pipe fittings that should normally conform to OD pipes, but it has a lasting impact on modern standards worldwide.
In North America and the UK, piping pressure is usually determined by Nominal Pipe Size (NPS) and schedule (SCH). The pipe size is documented by a number of standards, including API 5L, ANSI/ASME B36.10M (Table 1) in the US, and BS 1600 and BS 1387 in the UK. Usually the wall thickness of the pipe is a controlled variable, and the Inner Diameter (I.D.) is allowed to vary. The thickness of the pipe wall has a variant of about 12.5 percent.
Across Europe, pressure piping uses the same pipe ID and wall thickness as the Nominal Pipe Size, but marks it with the Nominal Diameter (DN) metric, not the imperial NPS. For NPS greater than 14, DN equals NPS multiplied by 25. (Not 25.4) This is documented by EN 10255 (formerly DIN 2448 and BS 1387) and ISO 65, and is often called DIN or ISO pipe.
Japan has its own set of standard pipe sizes, often called JIS pipes.
The size of Iron pipe (IPS) is an older system that is still used by some manufacturers and inheritance drawings and equipment. The IPS number is the same as the NPS number, but the schedule is limited to Standard Wall (STD), Strong Extras (XS), and Double Extra Strong (XXS). STD is identical to SCH 40 for NPS 1/8 to NPS 10, inclusive, and shows 0.375 wall thicknesses for NPS 12 and larger. XS is identical to SCH 80 for NPS 1/8 to NPS 8, inclusive, and shows. Wall thickness 500 "for NPS 8 and larger Different definitions exist for XXS, but never the same as SCH 160. XXS is actually thicker than SCH 160 for NPS 1/8" to 6 "inclusive, while SCH 160 is thicker than XXS for NPS 8 "and larger.
Another old system is Ductile Iron Pipe Size (DIPS), which generally has OD larger than IPS.
Copper plumbing for housing pipes follows a completely different size system in America, often called Copper Tube Size (CTS); see the domestic water system. Its nominal size is not inside or outside diameter. Plastic tubes, such as PVC and CPVC, for piping applications also have different size standards.
Agricultural applications use PIP sizes, which stands for Plastic Irrigation Pipes. PIP has a pressure rating of 22 psi (150 kPa), 50 psi (340 kPa), 80 psi (550 kPa), 100 psi (690 kPa), and 125 psi (860 kPa) and is generally available in 6 ", 8" 10 ", 12", 15 ", 18", 21 ", and 24".
Standard
The manufacture and installation of the pressure pipe is strictly regulated by the ASME "B31" code series such as B31.1 or B31.3 that have their base in ASME Boilers and Pressure Vessel Code (BPVC). This code has legal force in Canada and the US. Europe and the rest of the world have an equivalent code system. Pipe pressure is generally a pipe that should carry a pressure of more than 10 to 25 atmospheres, although the definition varies. To ensure safe operation of the system, manufacture, storage, welding, testing, etc. From pressure piping must meet stringent quality standards.
Manufacturing standards for pipes generally require chemical composition tests and a series of mechanical strength tests for each pipeline heat. The hot pipes are all forged from the same cast bars, and therefore have the same chemical composition. Mechanical tests may be associated with many pipes, all of which come from the same heat and have gone through the same heat treatment process. The manufacturer performs this test and reports the composition in the tracking report mill and mechanical testing in the material test report , both called by the MTR acronym. Materials with related test reports are called trackable . For critical applications, third party verification of these tests may be required; in which case an independent laboratory will produce a certified test certificate (CMTR), and the material will be called certified .
Some of the widely used pipe standards or piping classes are:
- API ranges - now ISO 3183. E.g.: API 5L Grade B - now ISO L245 with numbers indicating yield strength in MPa
- ASME SA106 Grade B (Seamless carbon steel pipe for high temperature service)
- ASTM A312 (austenitic stainless steel pipe welded and welded)
- ASTM C76 (Concrete Pipe)
- ASTM D3033/3034 (PVC Pipe)
- ASTM D2239 (Polyethylene Pipes)
- ISO 14692 (Manufacture of oil and natural gas Plastic reinforced pipe (GRP) Qualification and manufacturing)
- ASTM A36 (Carbon steel pipe for the use of structural or low pressure)
- ASTM A795 (Special steel pipe for fire sprinkler system)
API 5L was changed in the second half of 2008 to issue 44 of edition 43 to make it identical to ISO 3183. It is important to note that such changes have created a requirement that acidic services, ERW pipes, pass hydrogen-induced crack (HIC) test per NACE TM0284 agar can be used for acid services.
- ACPA [American Concrete Pipe Association]
- AWWA [American Water Works Association]
- AWWA M45
Installation
Pipe installation is often more expensive than the material and various specialized tools, techniques, and parts that have been developed to help this. Pipes are usually shipped to customers or workplaces either as "sticks" or pipe lengths (usually 20 feet, called single random lengths) or they are prefabricated with elbows, tee and valves into prefabricated tubing pipes. [A pipe roll is a pipe and fitting section pre-assemblies, usually put up in stores so that installation at construction sites can be more efficient.]. Typically, pipes smaller than 2.0 inches are not made before. Pipe rolls are usually marked with bar codes and ends are covered (plastic) for protection. Pipes and pipe rolls are sent to the warehouse on large commercial/industrial works and they can be held indoors or on the grid kite page. The pipe or spool of the pipe is taken, staged, rigged, and then lifted into place. In large work processes, lifts are made using cranes and hoist and other material lifts. They are typically temporarily supported in steel structures using beam clamps, ropes, and small hoists until plumbing support is installed or secured.
Examples of tools used for the installation of small pipe pipes (threaded ends) are pipe locks. The small pipe is usually not heavy and can be lifted into place by the craft worker installation. However, during a plant outage or shutdown, a small pipe (small hole) can also be made earlier to speed up installation during outages. Once the pipe is installed, it will be tested for leakage. Before testing it may need to be cleaned by blowing air or steam or flushing with liquid.
Pipe supports
Pipes are usually supported from the bottom or hung from the top (but may also be supported from the side), using a device called pipe support. Support may be as simple as a "shoe" pipe that is similar to half of I-beam welded to the bottom of the pipe; they may be "hung" using clevis, or by the trapeze type of a device called a pipe hanger. Any type of support pipe may incorporate a spring, snubber, silencer, or combination of these devices to compensate for thermal expansion, or to provide vibration isolation, shock control, or reduce excitation vibration from the pipe due to seismic movement. Some silencers are just dashpots, but other dampers may be active hydraulic devices that have sophisticated systems that act to quench peak movements due to external forced vibrations or mechanical shocks. Unwanted movements may be derived processes (such as in a fluidized bed reactor) or from natural phenomena such as earthquakes (basic design events or DBE).
Pipe hanger is usually installed with a pipe clamp. Possible exposures to high temperatures and heavy loads should be included when determining the necessary clamps.
Join
Pipes are usually connected with welding, using threaded pipes and fittings; sealing connection with pipe thread compound, Polytetrafluoroethylene (PTFE) Ribbon sealing tape, oakum, or PTFE string, or by using mechanical couplings. The piping process is usually connected by welding using a TIG or MIG process. The most common pipe connection process is the butt weld. The ends of the pipe to be welded must have a specific welding preparation called End Weld Prep (EWP) which is usually at an angle of 37.5 degrees to accommodate filler weld metal. The most common pipe threads in North America are the National Pipe Thread (NPT) or the Dryseal (NPTF) version. Other pipe threads include English standard pipe yarn (BSPT), garden hose yarn (GHT), and fire hose coupling (NST).
Copper pipes are usually connected with solder, brazing, compression fitting, flaring, or crimping. Plastic pipe can be connected with solvent welding, hot fusion, or elastomer sealing.
If frequent disconnections will be required, pipe flange gaskets or union fittings provide better reliability than threads. Some thin-walled pipes of brittle materials, such as copper pipes or smaller flexible plastics found in homes for ice makers and moisturizers, for example, can be combined with compression equipment.
The underground pipeline usually uses a "push-on" gasket pipe style that presses the gasket into the space formed between two adjacent pieces. A push-on connection is available in most types of pipes. Pipe connection lubricants should be used in pipe fitting. Under buried conditions, a joint-gasket pipe allows for lateral movement due to ground shifts as well as expansion/contraction due to temperature differences. MDPE plastics and HDPE gas and water pipes also often join Electrofusion fittings.
Large pipes above the ground usually use a flanged joint, which is generally available in ductile iron pipes and some others. This is a gasket force in which the flanges of adjacent pipes are put together, compressing the gaskets into the space between the pipes.
Mechanically grooved clutches or Victaulic joints are also often used for frequent disassembly and assembly. Developed in the 1920s, this mechanical threaded coupling can operate up to 120 pounds per square inch (830 kpa) working pressure and is available in materials to match pipeline levels. Another type of mechanical coupling is the Swagelok brand fitting; This type of compression fittings is usually used on small pipe below 0.75 inch (19 mm) in diameter.
When pipes join in spaces where other components are required for network management (such as valves or gauges), joint disassembly is commonly used, to make installation/fall easier.
Supplies and valves
Fittings are also used to divide or join a number of joint pipes, and for other purposes. A wide range of standard pipe fittings are available; they are generally broken down into tees, elbows, branches, dampers, or wye. The valve controls the fluid flow and regulates the pressure. Plumbing and pipe fittings and valve articles discuss it further.
Clean
The inside of the pipe can be cleaned by the cleaning process of the tube, if they are contaminated with debris or fouling. It depends on the process that the pipeline will be used for and the cleanliness required for the process. In some cases, pipes are cleaned by means of a displacement device officially known as Pipe Line Examiners or "pigs"; alternately tubes or tubes may be chemically flushed using a special solution that is pumped through. In some cases, where care has been taken in the manufacture, storage, and installation of pipes and tubing, the lines are blown clean with compressed air or nitrogen.
Other uses
Pipes are widely used in the manufacture of handrails, guardrails, and fences.
See also
References
Bibliography
External links
- Handling critical liquids with tubes
- Synthetic images of unlimited pipe fabrication animation:
- https://www.youtube.com/watch?v=ztcEyel47Kg
- https://www.youtube.com/watch?v=7ITgMXtuMv0
Source of the article : Wikipedia
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