thread- jamal

20
arious Thread T ypes of Pl umbing A Guide to Understanding the Many Styles of Fittings © Isaac M. McPhee Mar 3, 2008 There are very few elements of plumbing that confuse the average DIYer more than understanding the many types of threads and fittings and how they all fit together. A common exchange within the average hardware store: Customer: I need a new supply line for my kitchen faucet. Employee: Very good. Do you know what type of threads were on your old one? Customer: I think they were just the "normal" threads. Such are the common mistakes made by a great many DIYers who have not had any real  plumbing experience. The problem here is that there are no "normal" threads in  plumbing. There are very few cu t-and-dried instances where only one type may be u sed. There are some which are more common than others, to be sure, but rarely are there certainties. While common projects, such as replacing a supply line, are fairly simple and can generally be done by the average homeowner or renter, issues like this are commonplace. Inexperienced plumbers often forget to bring the old part in with them (which would solve this problem veyr quickly) or they forget to really look at the old part in order to see what kind of fittings were on either side. What makes this even more difficult is that in addition to plumbing threads comming in different sizes, they also come in completely different styles, all of which serve very specific and distinct purposes. Common supply lines, for instance, g enerally have a 1/2- inch pipe thread on the end which attaches to the faucet, and one of three sizes on the end

Transcript of thread- jamal

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 1/20

arious Thread Types of Plumbing

A Guide to Understanding the Many Styles of Fittings

© Isaac M. McPhee

Mar 3, 2008

There are very few elements of plumbing that confuse theaverage DIYer more than understanding the manytypes of threads and fittings and how they all fittogether.

A common exchange within the average hardware store:

Customer: I need a new supply line for my kitchen faucet.

Employee: Very good. Do you know what type of threads were on your old one?

Customer: I think they were just the "normal" threads.

Such are the common mistakes made by a great many DIYers who have not had any real plumbing experience. The problem here is that there are no "normal" threads in plumbing. There are very few cut-and-dried instances where only one type may be used.There are some which are more common than others, to be sure, but rarely are therecertainties.

While common projects, such as replacing a supply line, are fairly simple and cangenerally be done by the average homeowner or renter, issues like this are commonplace.Inexperienced plumbers often forget to bring the old part in with them (which wouldsolve this problem veyr quickly) or they forget to really look at the old part in order to seewhat kind of fittings were on either side.

What makes this even more difficult is that in addition to plumbing threads comming indifferent sizes, they also come in completely different styles, all of which serve veryspecific and distinct purposes. Common supply lines, for instance, generally have a 1/2-inch pipe thread on the end which attaches to the faucet, and one of three sizes on the end

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 2/20

which attaches to the valve - 3/8-inch compression, 1/2-inch compression, or 1/2-inchFIP.

What does all this mean?

Pipe Threads

The most common plumbing thread are standard, tapered pipe threads. On the packagingfor products utilizing this thread it will say either MIP (male pipe thread), FIP (female

pipe thread) or NPT (national pipe thread). These are the standard threads on galvanized, black iron, pvc, copper and other pipe fittings. These threads are tapered in order to createa water-tight seal, but they must be used in conjunction with teflon thread tape or jointcompound in order to function properly (white teflon if used with water, yellow if usedon gas-carrying iron pipe).

Compression Threads

Compression threads are much smaller than pipe threads, as they are measured using thesize of the corresponding pipe (usually copper tubing), rather than the threads themselves.As a result, they can be very confusing for the average consumer, who can't understandhow a 1/2-inch compression thread can be so much smaller than a 1/2-inch pipe thread(shouldn't they be the exact same size?).

Compression threads are not tapered, which means they should not be used with teflontape (teflon tape or other joint compounds can actually prevent them from sealing). Thesethreads are most commonly used to create a water-tight seal over copper or plastic tubing,in conjunction with a metal (or plastic) ferrul (the compression nut tightens down on the

ferrul, which "compresses" onto the pipe, hence the name). These threads can be found,however, in other situations.

The aforementioned situation with the faucet supply line, for instance, often usescompression threads. Angle Valves often use compression fittings to attach to copper

pipes coming out of the wall, then have another compression fitting for the supply line(the reasoning here is that one could potentially use copper tubing in order to make asupply line, rather than buying a "prefabricated" one, though this is becoming more rare).

Compression fittings can show up in other odd places, however, so it is best to watch outfor this.

Flare Fittings

Flare fittings often show up in automotive and gas-line applications, but they can exist instandard home plumbing as well. These fittings, like compression fittings, are nottapered, so teflon tape should not be used with them. They are used in copper tubingapplications, where a special "flaring tool" is used to put a flare on the end of a copper

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 3/20

tubing, which seats down inside a flare fitting, which then threads onto another fitting,causing the copper to seat neatly down onto the fitting's "seat."

Flare fittings are often very confusing to the average DIYer because they are very closein size to standard pipe-threads, but are not at all interchangeable. In addition, where pipe

threads only exist in certain, very specific sizes (1/8", 1/4", 3/8", 1/2", 3/4", etc.), flarethreads exist in different sizes, such as 5/8" and 15/16".

Finding the Right Thread While it can be difficult for all but the most experience plumber to be able to tell by sight which style of thread is which, many hardware storeshave sizing guages or charts which can help to determine which fittings or adaptors areneeded for each application. So, once again, the best course of action is to bring parts intothe store. If nothing else, the store employees can simply try the different availablefittings until they find the ones that work.

It is for this reason that plumbing can be a very difficult, time consuming process until

one gets the hang of it. Simply understanding a bit about the different types of threads,though, can hopefully help to ease a bit of that frustration.

A Compression Tee

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 4/20

he British Standard Pipe thread (BSP thread) is a family of standard screw thread types

that has been adopted internationally for interconnecting and sealing pipe ends by matingan external (male) with an internal (female) thread.

Contents

[hide ]

• 1 Types• 2 Threadform• 3 Pipe thread sizes• 4 Pipe thread designations• 5 References• 6 See also

• 7 External links

[edit ] Types

Two types of threads are distinguished:

• Parallel threads, which have a constant diameter.(G)•

Taper threads, whose diameter increases or decreases along the length of thethread.(R)

They can be combined into two types of joints:

• Jointing threads: These are pipe threads for joints made pressure-tight by themating of the threads. They always use a taper external thread, but can have either

parallel or taper internal threads. (In Continental Europe, taper internal pipethreads are not commonly used.)

• Longscrew threads: These are parallel pipe threads used where a pressure-tight joint is achieved by the compression of a soft material ( gasket ) on to the surface

of the external thread by tightening a backnut against a socket.

[edit ] Threadform

For both the taper and the parallel pipe threads, the Whitworth thread form is used, whichhas the following characteristics:

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 5/20

• symmetrical V-thread in which the angle between the flanks is 55° (measured inan axial plane)

• one-sixth of this sharp V is truncated at the top and the bottom• the threads are rounded equally at crests and roots by circular arclend tangentially

with the flanks•

the theoretical depth of the thread is therefore 0.64times the nominal pitch therelation between

[edit ] Pipe thread sizes

A list of 15 thread sizes are defined by the standards, ranging from 1/16 to 6. The sizenumber was originally based on the inner diameter measured in inches (25.4 mm) of asteel tube for which the thread was intended, but is in the modern metric version of thestandard simply a size number.

Threadsize

Threadsper inch

Pitch[mm]

Major diameterof the thread Gauge

length[mm]

Corresponding pipe

[mm] [in] DN OD[mm]

OD[in]

Thick-ness

[mm]1/16 28 0.907 7.723 0.304 41/8 28 0.907 9.728 0.383 4 6 10.2 0.40 21/4 19 1.337 13.157 0.518 6 8 13.5 0.53 2.33/8 19 1.337 16.662 0.656 6.4 10 17.2 0.68 2.31/2 14 1.814 20.995 0.825 8.2 15 21.3 0.84 2.63/4 14 1.814 26.441 1.041 9.5 20 26.9 1.06 2.6

1 11 2.309 33.249 1.309 10.4 25 33.7 1.33 3.21¼ 11 2.309 41.910 1.650 12.7 32 42.4 1.67 3.21½ 11 2.309 47.803 1.882 12.7 40 48.3 1.90 3.22 11 2.309 59.614 2.347 15.9 50 60.3 2.37 3.62½ 11 2.309 75.184 2.960 17.5 65 76.1 3.00 3.63 11 2.309 87.884 3.460 20.6 80 88.9 3.50 44 11 2.309 113.030 4.450 25.5 100 114.3 4.50 4.55 11 2.309 138.430 5.450 28.6 125 139.7 5.50 56 11 2.309 163.830 6.450 28.6 150 165.1 6.50 5

The major diameter listed is the outer diameter of the external thread. For a taper thread,it is the diameter at the "gauge length" from the small end of the thread. The taper is "1 to16", meaning that for each 16 mm increase in the distance from the end, the diameter increases by 1 mm.

[edit ] Pipe thread designations

These standard pipe threads are formally referred to by the following sequence of blocks:

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 6/20

• the words "Pipe thread",• the document number of the standard (e.g., "ISO 7" or "EN 10226")• the symbol for the pipe thread type:

o G = external+internal parallel (ISO 228)o R = external taper (ISO 7)o Rp = internal parallel (ISO 7)o Rc = internal taper (ISO 7)

• the thread size

Threads are normally right-hand. For left-hand threads, the letters "LH" are appended.

Example: Pipe thread EN 10226 Rp 2 1/2

[edit ] References• International standard ISO 7-1: Pipe threads where pressure-tight joints are made

on the threads — Part 1: Dimensions, tolerances and designation. InternationalOrganization for Standardization , Geneva.

• BS EN 10226: Pipe threads where pressure tight joints are made on the threads.(The European version of ISO 7)

o Part 1: Taper external threads and parallel internal threads — Dimensions,tolerances and designation.

o Part 2: Taper external threads and taper internal threads — Dimensions,tolerances and designation.

• BS 21: Pipe threads for tubes and fittings where pressure-tight joints are made onthe threads (metric dimensions). British Standards Institute , 1985. (Superseded byBS EN 10226:2004).

• International standard ISO 228-1: Pipe threads where pressure-tight joints are notmade on the threads — Part 1: Dimensions, tolerances and designation.

• BS 2779: Specification for pipe threads for tubes and fittings where pressure-tight joints are not made on the threads (metric dimensions), 1986.

BS EN 10226-1:2004

[edit ] See also• Threaded pipe•

National pipe thread

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 7/20

Threaded pipeFrom Wikipedia, the free encyclopedia

Jump to: navigation , search

A threaded pipe plug; note that the threaded portion is tapered and so touches the calipersat only two points.

A threaded pipe is a pipe with screw-threaded ends for assembly. Threads are generallyslightly conical (aka tapered) rather than cylindrical (like a bolt or power screw ). As aresult a threaded pipe joint is much like a conical plug plugging a conical hole. Inaddition, the threads act as a labyrinth seal . While no gasket is needed, a coating isusually applied to the threads such as Teflon tape .

Especially precise threads are known as "dry fit" or "dry seal" meaning that no sealant isrequired for a gas-tight seal. Such threads are needed where the sealant wouldcontaminate or react with the media inside the piping, e.g., oxygen service.

Due to the taper (cone) of the thread, when such threads are cut by a tap or a die,increasingly more material is being cut at a time as the length of the thread is increased.Beyond a pipe sizes of a fraction of an inch, it is therefore common to use powered toolswhen cutting such threads.

Threaded fittings are sometimes used on plastic piping. Due to the wedging effect of thetapered thread, extreme care must be used to avoid overstressing the female componentof the joint. It is not uncommon for such fittings to split days, weeks, or even years after initial installation, and therefore many municipal plumbing codes restrict the use of threaded plastic pipe fittings.

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 8/20

Nominal Pipe SizeFrom Wikipedia, the free encyclopedia

Jump to: navigation , search

Nominal Pipe Size (NPS) is a set of standard pipe sizes used for pressure piping in NorthAmerica. The same pipe dimensions are used with different names in Europe. It is oftenincorrectly called National Pipe Size, due to confusion with National pipe thread . For other pipe size standards, see pipe (material) .

Pipe size is specified with two non-dimensional numbers: a Nominal Pipe Size (NPS) anda schedule (SCH). The relationship of these numbers to the actual pipe dimensions is a bitstrange. The NPS is very loosely related to the inside diameter in inches, but only for

NPS 1/8 to NPS 12. For NPS 14 and larger, the NPS is equal to the outside diameter

(OD) in inches. For a given NPS, the OD stays constant and the wall thickness increaseswith larger SCH. For a given SCH, the OD increases with increasing NPS while the wallthickness increases or stays constant. Pipe sizes are documented by a number of standards, including API 5L, ANSI /ASME B36.10M in the US, BS 1600 and BS EN10255 in the United Kingdom and Europe, and ISO 65 internationally. The ISO andEuropean standard uses the same pipe ID's and wall thicknesses, but labels them with aDiametre Nominal (DN) instead of NPS. For NPS of 5 and larger, the DN is equal to the

NPS multiplied by 25 (not 25.4).

The most commonly used schedules today are 40, 80, and 160. There is a commonly held belief that the schedule number is an indicator of the service pressure that the pipe can

take. For example, the McGraw Hill Piping Handbook says the schedule number can beconverted to pressure by dividing the schedule by 1000 and multiplying by the allowablestress of the material (Ref. #2). However, this is not true. Using equations and rules inASME B31.3 Process Piping, it is easily shown that pressure rating actually goes downwith increasing NPS and constant schedule.

The various standards for pipe schedule are not identical. Frequently some sizes—or evenentire schedules—are present in some standards but not others. When different standardsdo overlap, they usually have the same dimensions. For this reason, the source of theschedules is not distinguished in the table below. Beyond NPS 8, however, there are twodifferent versions of schedules 5, 10, 40, and 80. In newer standards and in the table

below, the distinction is denoted by the presence or absence of an 'S' suffix after theschedule number. The 'S' was originally meant to indicate Stainless Steel Schedule (Ref.#3, pp B-16 and B-17), but in practice, pipe of any material may be available in either schedule depending on the manufacturer.

Some specifications use pipe schedules called Standard Wall (STD), Extra Strong (XS),and Double Extra Strong (XXS), although these actually belong to an older system callediron pipe size (IPS). The IPS number is the same as the NPS number. STD is identical to

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 9/20

SCH 40S, and 40S is identical to 40 for NPS 1/8 to NPS 10, inclusive. XS is identical toSCH 80S, and 80S is identical to 80 for NPS 1/8 to NPS 8, inclusive. Differentdefinitions exist for XXS, but it is generally thicker than schedule 160.

Copper plumbing tube for residential plumbing follows an entirely different size system;

see domestic water system . Both polyvinyl chloride pipe (PVC) and chlorinated polyvinyl chloride pipe (CPVC) are made in NPS sizes. CPVC has a roughly 50°C higher temperature limit which makes it suitable for use in domestic hot water service.

Contents

[hide ]

• 1 NPS 1/8 to NPS 3-1/2• 2 NPS 4 to NPS 8• 3 NPS 10 to NPS 24• 4 See also

• 5 References

[edit ] NPS 1/8 to NPS 3-1/2

NPS DN OD (inches)Wall Thickness (inches)

SCH 5 SCH 10 SCH 30 SCH 40 SCH 80 SCH 120 SCH 160

1/8 6 0.405 0.035 0.049 0.057 0.068 0.095 ? ?

3/16 7 ? ? ? ? ? ? ? ?1/4 8 0.540 0.049 0.065 .073 .088 .119 ? ?

3/8 10 0.675 .049 .065 .073 .091 .126 ? ?

1/2 15 0.840 .065 .083 .095 .109 .147 .170 .188

5/8 18 ? ? ? ? ? ? ? ?

3/4 20 1.050 .065 .083 .095 .113 .154 .170 .219

1 25 1.315 .065 .109 .114 .133 .179 .200 .250

1-1/4 32 1.660 .065 .109 .117 .140 .191 .215 .250

1-1/2 40 1.900 .065 .109 .125 .145 .200 .225 .281

2 50 2.375 .065 .109 ? .154 .218 .250 .344

2-1/2 65 2.875 .083 .120 ? .203 .276 .300 .375

3 80 3.500 .083 .120 ? .216 .300 .350 .438

3-1/2 90 4.000 .083 .120 ? .226 .318 ? ?

[edit ] NPS 4 to NPS 8

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 10/20

NPS DN OD(inches)

Wall Thickness (inches)

SCH5

SCH10

SCH20

SCH30

SCH40

SCH60

SCH80

SCH100

SCH120

SCH140

SCH160

4 100 4.500 .083 .120 ? ? .237 .281 .337 ? .437 ? .531

4-1/2 115 5.000 ? ? ? ? .247 ? .355 ? ? ? ?5 125 5.563 .109 .134 ? ? .258 ? .375 ? .500 ? .625

6 150 6.625 .109 .134 ? ? .280 ? .432 ? .562 ? .719

8 200 8.625 .109 .148 .250 .277 .322 .406 .500 .593 .718 .812 .906

[edit ] NPS 10 to NPS 24

NP

S

D

N

OD(inche

s)

Wall Thickness (inches)

SC

H5s

SCH 5

SC

H10s

SC

H10

SC

H20

SC

H30

SC

H40s

SC

H40

SC

H60

SC

H80s

SC

H80

SC

H100

SC

H120

SC

H140

SCH160

10 250

10.75 .134 .134 .165 .165 .250 .307 .365 .365 .500 .500 .593 .718 .843 1.000 1.125

12 300

12.75 .156 .165 .180 .180 .250 .330 .375 .406 .500 .500 .687 .843 1.000

1.125 1.312

14 350

14.00 .156 .188 .250 .312 .375 .375 .437 .593 .500 .750 .937 1.093

1.250 1.406

16 400

16.00 .165 .188 .250 .312 .375 .375 .500 .656 .500 .843 1.031

1.218

1.437 1.593

18 450

18.00 .165 .188 .250 .312 .437 .375 .562 .750 .500 .937 1.156

1.375

1.562 1.781

20 500

20.00 .188 .218 .250 .375 .500 .375 .593 .812 .500 1.031

1.280

1.500

1.750 1.968

24 600

24.00 .218 .250 .250 .375 .562 .375 .687 .968 .500 1.218

1.531

1.812

2.062 2.343

[edit ] See also

National pipe thread

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 11/20

From Wikipedia, the free encyclopedia

Jump to: navigation , search

Threaded pipe and elbow

National Pipe Thread is a U.S. standard for tapered (NPT) or straight (NPS) threadsused to join pipes and fittings. ANSI /ASME standard B1.20.1 covers threads of 60-degree form with flat crests and roots in sizes from ¹⁄ inch to 24 inch₁₆ Nominal Pipe

Size . The taper rate for all NPT threads is ¹⁄ (³⁄ inch per foot) measured by the change₁₆ ₄ of diameter (of the pipe thread) over distance. The taper divided by a center line yields anangle 1° 47' 24" or 1.7899° as measured from the center axis. Commonly-used sizes are¹⁄ , ¹⁄ , ³⁄ , ¹⁄ , ³⁄ , 1, 1 ¹⁄ , 1 ¹⁄ , and 2₈ ₄ ₈ ₂ ₄ ₄ ₂ inch , appearing on pipe and fittings by most U.S.suppliers. Smaller sizes than those listed are occasionally used for compressed air. Larger sizes are used less frequently because other methods of joining are more practical at 3inches and above in most applications.

Nominal Pipe Size is loosely related to the inside diameter of schedule 40 pipe. Becauseof the pipe wall thickness, the actual diameter of the threads is larger than the NPS,considerably so for small NPS. Other schedules of pipe have different wall thickness but

the OD (outer diameter) and thread profile remain the same, so the inside diameter of the pipe is therefore different from the nominal diameter.

Threaded pipes can provide an effective seal for pipes transporting liquids , gases , steam ,and hydraulic fluid. These threads are now used in materials other than steel and brass,including PVC , nylon , bronze and cast iron .

The taper on NPT threads allows them to form a seal when torqued as the flanks of thethreads compress against each other, as opposed to straight thread fittings or compressionfittings in which the threads merely hold the pieces together and do not provide the seal.However a clearance remains between the crests and roots of the threads, resulting in a

leakage around this spiral. This means that NPT fittings must be made leak free with theaid of thread seal tape or a thread sealant compound. (The use of tape or sealant will alsohelp to limit corrosion on the threads, which can make future disassembly nearlyimpossible.)

There is also a semi-compatible variant called NPTF or Dryseal, designed to provide amore leak-free seal without the use of teflon tape or other sealant compound. NPTF

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 12/20

threads are the same basic shape but with crest and root heights adjusted for aninterference fit, eliminating the spiral leakage path.

Sometimes NPT threads are referred to as MPT (Male Pipe Thread), MNPT, or NPT(M)for male (external) threads and FPT (Female Pipe Thread), FNPT, or NPT(F) for female

(internal) threads. An equivalent designation is MIP (Male iron pipe) and FIP (Femaleiron pipe).

Contents

[hide ]

• 1 Pipe thread sizes• 2 References• 3 See also

• 4 External links

[edit ] Pipe thread sizes

NominalNPT Size

OuterDiameter

Threadsper inch

Pitchof Thread

1/16" 0.3125" 27 0.037041/8 " 0.405" 27 0.037041/4 " 0.540" 18 0.055563/8 " 0.675" 18 0.055561/2 " 0.840" 14 0.071433/4 " 1.050" 14 0.071431 " 1.315" 11½ 0.086961¼ " 1.660" 11½ 0.086961½ " 1.900" 11½ 0.086962 " 2.375" 11½ 0.086962½ " 2.875" 8 0.125003 " 3.500" 8 0.125004 " 4.500" 8 0.125005 " 5.563" 8 0.125006 " 6.625" 8 0.1250010 " 10.750" 8 0.1250012 " 12.750" 8 0.1250014 " OD 14 " 8 0.1250016 " OD 16 " 8 0.1250018 " OD 18 " 8 0.1250020 " OD 20 " 8 0.12500

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 13/20

24 " OD 24 " 8 0.12500

Compression fittingFrom Wikipedia, the free encyclopedia

Jump to: navigation , search

A compression fitting 15 mm isolating valve

Compression fittings are used in plumbing and electrical conduit systems to join twotubes or thin-walled pipes together. In instances where two pipes made of dissimilar materials are to be joined (most commonly PVC and copper ), the fittings will also bemade of one or more compatible materials appropriate for the connection. Compressionfittings for attaching tubing (piping) commonly have ferrules in them.

Compression fittings are also used extensively for hot and cold water faucets and toiletstop valves. These valves generally control water to one fixture, such as a toilet, to allowit to be serviced without turning off the water to the entire house. Compression fittingsare well suited to this application, as these valves are usually located in confined spaceswhere copper pipe would be difficult to solder without creating a fire hazard.

Contents

[hide ]

• 1 How they work • 2 Types of fittings• 3 Advantages• 4 Disadvantages• 5 Additional information

• 6 See also

[edit ] How they work

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 14/20

As the name implies, compression fittings form a tight seal by applying a compressiveforce to the pipes and pipe fitting. The fitting is compressed against the pipe with a forcesufficient to eliminate all space remaining in the joint, thus preventing fluid from leaking.

The compression fitting is composed of an outer "compression nut" and an inner ring

called a "ferrule" or "olive" in the UK. This is usually made of brass or copper. When thenut is tightened, it clamps-down on the ferrule, causing it to conform to the circumferenceof the pipe. Ferrules vary in shape and material according to the pipe material. To work

properly, the ferrule must be oriented correctly. Typically the ferrule is fitted such thatthe longest sloping face of the ferrule faces away from the nut.

It is important to remember to not apply joint compound or teflon tape to a compressionfitting's threads. The compression is the means of sealing the joint, not the sealing of thethreads themselves. Pipe compound or teflon tape will frequently lead to a leak in thefitting by causing the fitting to loosen as a reaction to the compression. Joint compound isusually applied to the ferrule or Olive to seal imperfections in the fitting. In a standard

threaded connection, pipe compound and teflon tape act to seal the threads from the water pressure.

In addition, it is critically important to the integrity of the fitting that excessive force isavoided in tightening the nut. If the fitting is overtightened, the ferrule will deform andcause leaks. Overtightening is the most common cause of leaks in compression fittings.As a general rule, a compression fitting should be "finger tight" and then tightened 1 turnwith a wrench. The fitting should then be tested, and if slight weeping is observed, thefitting should be slowly tightened a bit more until the weeping stops.

[edit ] Types of fittings

There are two common types of compression fitting, standard (British: Type-A/non-manipulative) and "flare" fittings (British: Type-B/manipulative). Standard fittingsrequire no modifications to the tubing. Flare fittings require modification of the tubingwith a special tool. Standard fittings are generally used for water and compressed air connections, while flare fittings are used for gas and high pressure lines.

A standard fitting can be installed using an ordinary wrench to tighten the surroundingnut. To remove it, a specialized pulling tool is often used to slide the nut and ferrule off the tube.

[edit ] Advantages

Compression fittings are popular because they do not require soldering, so they arecomparatively quick and easy to use. Compression fittings are especially useful ininstallations that may require occasional disassembly or partial removal for maintenanceetc, since these joints can be broken and remade without affecting the integrity of the

joint. They are also used in situations where a heat source, in particular a soldering torch,

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 15/20

is prohibited; however, they are more expensive than other types of fittings and mayrequire more space.

[edit ] Disadvantages

Compression fittings are not as robust as soldered fittings. They should be used inapplications where the fitting will not be disturbed and not subjected to flexing or

bending. A soldered joint is highly tolerant of flexing and bending (such as when pipesknock or shake from sudden pressure changes). Compression fittings are much moresensitive to these type of dynamic stresses.

[edit ] Additional information

This worksheetassumes you are notusing self tappingconnections.Therefore make sureyou cut the supplyto the pipe you areworking on. Seeworksheet 'Drainingthe water pipes ' for more details.

Procedures for joining copper pipesfall into threecategories accordingto the types of jointused; end-feed(1),

pre-soldered(2) andcompression(3).Making soldered

joints is simple after some practice andwe suggest tryingout these procedures

before attemptingany real projects.

First determine thelengths of pipeneeded, notforgetting to allowfor the pipe that sitsinside the joint

piece. Cut the pipesto length ensuringthat the ends are

perfectly square,ideally using a

plumbers pipe cutter to acheive perfectresults.

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 16/20

To use a pipe cutter,mark the pipe whereyou wish to cut,then align the wheelon the cutter andtighten against the

pipe. Rotate the toolaround the pipe,tightening the cutter after each full turnuntil you are all theway through. Usethe pointed end of the cutter to cleanthe burrs frominside the pipe.

If you are unable toget hold of a pipecutter then use ahacksaw to cut the

pipe. Tightly wrapsome paper with astraight edge aroundthe pipe, aligningthe edge to use as aguide for thehacksaw. Thenremove the sharp

burrs of metal insideand out with a file.

Copper must becompletely clean

before soldering cantake place. Toachieve this, rub theend with wire woolthen paint flux ontothe section of pipeto be pushed intothe connector. Fluxis used to removeany dirt and greasethat conventionalcleaning wouldleave behind.

Push the pipe intothe connector until itstops, then wipe off any excess fluxfrom around the

joint. Place theceramic tile behindwhere you will beusing the gas torchthen fix the pipes in

place with pipe-clips. Heat the jointuntil you can see

Remove the flameand touch the solder around the entranceto the joint. Thenheat the joint again

until the solder creates a completering around the

pipe. Capiliaryaction should drawthe solder down intothe joint to create awater-tight seal.

Clean and flux the joints as for end-feed joints. Becausethe solder neededfor the joint is

already in place,make sure you fullyassemble anymultiple joints

before heating,otherwise you willmelt all the solder intended for the

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 17/20

vapours from theflux inside the joint.

Leave the joint for about 20 mins tocool.

other parts of theconnection.

Fix the pipes in place with pipeclips, then place theceramic tile behindwhere you will beusing the gas torch.Heat the joint untilyou see a ring of solder appear around theconnection. Heat all

parts of a multiple joint in the sameoperation. Leave the

joint for about 20mins to cool.

This a strong, butsimple way of

joining pipes,however it is vitalthat the tightness of the nut is correct;too loose and it willleak, too tight andthe joint may break under the strain.These joints are not

practical for confined spaces asspanners are neededto tighten the nuts.

A compression jointworks by tighteninga nut against a ringof copper - called anolive - against the

pipe to create awater tight joint.When you dismantlethe joint, take careto note which wayround the olive isfitted. If you forget,the longest slopingface of the olivenormally faces awayfrom the nut.

Take your cut andsmoothed pipe, andslip the nut andolive over the endand push the pipeinto the joint as far as it will go. Youmay wish to smear

To make sure thenut is correctlytightened, make amark on the pipeand nut, then usingthe two adjustablespanners, turn thenut one full rotation

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 18/20

some jointingcompound aroundthe olive to ensurewater tightness. Fitthe nut to hand tight

only at this point.

until the marks meetup again. Test your installation to check for leaks, make onequarter turn on any

joint that appears to be weeping.

Note:Please read and understand the section DIY Safety

before undertaking any of the projects outlined onthese pages.

Some jobs require planning permission from your Local Authority. Seek their advice before starting any

work that you are unsure of.

Should any difficulties arise or if you are in any doubt,we strongly reccommend that you contact a

professional tradesperson.

Please read o ur disclaimer

Flare fittingFrom Wikipedia, the free encyclopedia

Jump to: navigation , searchThis article does not cite any references or sources . (February 2008)Please help improve this article by adding citations to reliable sources . Unverifiable material may

be challenged and removed.

Flare Fittings are a type of compression fitting used with metal tubing, usually ductile(soft) copper, though other materials are also used.

The male half of the fitting has a straight thread and an angled front face (usually 45° or 37°). A matching nut is placed on the tubing, and a flare tool is used to flare the end of the tubing outward at the same angle. The nut is then tightened, compressing the flared

portion of the tubing between the male fitting and the nut. Flare fittings offer a highdegree of long term reliability and for this reason are often used in mission-critical andinaccessible locations.

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 19/20

There are several styles of flare fitting available, including the 45° SAE style (available atmany hardware stores, and very commonly used), the 37° AN style, and JIC . Note that45° and 37° flare fittings and tools are incompatible and should not be mixed.

Ads by GooglePipe Support Products Custom designed and fabricated pipe supports, pipe hangers, and clamps www.pipingtech.comPipe Fitting Reliable Suppliers - Contact Now! Search, Browse or PostBuying Leads www.Alibaba.comPipe Beveling Machines Th. Wortelboer BV manufacturer of PBM

pipe beveling machines www.wortelboer.wsAPI 5L X52 - X70 Pipe X52 - X70 Pipe, Fittings & Flanges HighYield Piping From Stock! www.offshorepipelinesolutions.com

XClose this window

Pipe thread is a spiral ridge on the end of a pipe that enables pipes to be joined together.For male fittings, pipe thread appears on the outer diameter of the pipe; if female, the

pipe thread appears on the inner diameter. By rotating a male pipe end into a female pipethread, the two fittings become joined.

Since male and female pipe thread must align successfully to form a connection,manufacturers follow pipe thread industry standards. The two main pipe thread standardsare the National Pipe Thread (NPT) , and the National Standard Free-Fitting StraightMechanical Pipe Thread (NPSM). NPT is a tapered pipe thread that can make a close-fitting wet seal. NPSM is a straight pipe thread that only forms a mechanical seal and isnot used for liquid applications. In the United States, garden hoses have their own pipethread standard (GHT), as do fire hose couplings, which use the National StandardThread (NST).

When joining NPT tapered pipe thread to make a leak-proof seal, professionalsrecommend using a sealer such as polytetrafluoroethylene (PTFE) pipe thread tape .PTFE, more commonly known as Teflon , is also the name of the best known brand of sealing tape. Tape should be wound tight around the male pipe threads, running in thesame direction as the lead thread so that the turning motion of joining the pipes followsthe tape's winding direction. Sealing tape makes it easy to drive the male pipe deeper byallowing the threads to slip past one another, while filling minute gaps to preventseepage. Pipe thread tape also makes it easier to disassemble the joint later, if need be, byreducing thread galling, or the tendency of some types of pipe threads to stick together over time.

8/7/2019 thread- jamal

http://slidepdf.com/reader/full/thread-jamal 20/20

Modern pipe sizes are stipulated by a measurement of the outer diameter (OD), which ismeasured over the pipe thread in the case of a male pipe. To be sure that the pipe threadwill match, you can also count the threads per inch (TPI). The inner diameter (ID) issometimes used when buying polyvinyl chloride , or PVC, pipes.

Building codes require that piping meet certain standards depending on the application.Pressurized gas or liquid, natural gas , potable water and underground drainage pipes will be made of different materials. Note that local laws might require that only licensedcontractors work on gas lines. Before undertaking any home piping project, check local

building codes and take proper safety precautions.