Pipe Fittings (Piping Systems)

transcript

PIPE FITTINGS, AND FLANGESPREPARED BY

dr MOUFFAK TAHA ALI

(dr_mouffak2005@yahoo.com)

GENERAL COMPOSITION OF

THE PIPING

GENERAL COMPOSITION OF THE PIPING

Piping system consists of the following components:

1 .The actual pipes

2 .The fittings: tees, elbows, reducers, etc….

3 .The range of connections: flanges, threaded fittings, weld

fittings, etc….

4 .The range of seals: gaskets, etc….

Piping and connections

COPPER PIPING

Copper tubes are best adapted for

cold/hot water and gas pipes .

It is sometimes necessary to anneal a tube

to improve its malleability.

Use a torch to heat the tube to redness

on the part which is to be annealed .

This work can be done with a

blowtorch (oxy-acetylene)

Annealing

COPPER PIPING

OLIVE COMPRESSION FITTINGS: These olive compression fittings

simplify the installation, but they cannot withstand several

disassemblies .

GRIP FITTING: For a beginner this principle is the easiest and has the

advantage of being indefinitely detachable.

Olive compression fitting Grip fitting

COPPER PIPING

FLARE FITTING

It consists of a female nut and a male union fitting.

This fitting requires the installation of a fibre or rubber

gasket for the sealing.

COPPER PIPING

PROGRESSIVE RING FITTINGS (ERMETO):

The Ermeto fitting is very popular due to its easy assembly which only needs two open spaners.

SPHERICAL SEAT UNION:

The tightening of the nut locally crushes the metal thus

procuring a tight seal.

Ermeto Spherical seat

COPPER PIPING

Weld fittings

There are several kinds of copper weld fittings .

With copper piping, the term “welding” is not used; we speak of

soldering or brazing .

Soldering and brazing consist of a lapped joint assembly of two

pieces of metal by capillarity, using a welding rod.

Brazing

COPPER PIPING

The difference between soldering and brazing:

1 .Soldering (melting point less than 450°C)

2 .Brazing (melting temperature higher than 450°C)

9Soldering Brazing

. In brazing, the filler metal melts at a higher temperature, but the work piece metal does not melt. In the past, nearly all solders contained lead, but environmental concerns have increasingly dictated use of lead-free alloys for electronics and plumbing purposes

Soldering is a process in which two or more metal items are joined together by melting and flowing a filler metal (solder) into the joint, the filler metal having a lower melting point than the adjoining metal . Soldering differs from welding in that soldering does not involve melting the work pieces

COPPER PIPING

Two things should be noted when speaking of soldering or brazing:

This is a capillary phenomenon (where a liquid spreads between

the cracks of two parts in contact and which slowly progresses

whatever the position of the parts)

Wetting (when the bond between the soldering or brazing and the

work piece is free of apparent defects and the coating of the

soldering or brazing appears even)

11Welding sleeves:

STEEL PIPING

The steel pipes are much larger than those made of copper but

steel pipes can also be found in small sizes.

Steel is divided into three categories :

1 .Non-alloy steels

2 .Alloy steels

3 .Stainless steels

STEEL PIPING

The choice of steel for the piping depends on the nature,

temperature and pressure of the fluid transported.

To connect steel pipes the electrical welding( with welding

electrodes) process is used for big diameters .

BUTT WELD FITTINGS

1 .Reducing T-pieces

2 .Reducers Concentric

3 .Reducers Eccentric

4 .Elbows 90°

5 .Collars

6 .Stub-ends

7 .T-pieces

8 .Caps

PIPE FITTINGS

Pipe fitting such as elbow, tees, reducers, etc. are used to:

1 .Change flow directions

2 .Change size and geometry of the line

3 .Fittings are manufactured from the same pipe materials.

4 .Fittings must have the same pressure rating of piping system and

corrosion resistance to the conveyed flow.

PIPE FITTINGS

Elbows

Elbows may be 180, 90 and 45 degrees. The radius of curvature is

generally equal to 1 or 1.5 times the nominal diameter .

They are used to change the direction by 45, 90, or 180.

TEE: used to connect three pipes together and branching a pipe

line at 90

CROSS: used to connect four pipes together

FITTINGS

Weld bend welding fittings are permanently identified by die

marking to designate:

1 .Manufacturer

2 .Size

3 .Wall Thickness

4 .Material Grade

5 .Heat Identification

WELDING FITTINGS (SHORT AND LONG RADIUS ELBOWS AND RETURN BENDS)

WELDING FITTINGS

WELDING FITTINGS (SHORT AND LONG RADIUS ELBOWS AND RETURN BENDS)

90 degrees elbows

180 degrees elbow (Return bends)

PIPE FITTINGS ( REDUCERRS)

To connect two pipes with two different diameters

PIPE FITTINGS (BUTT – WELDING TEES)

TEE: used to connect three pipes together and branching a pipe line at 90

Butt- welding Tees

Straight butt-welding Tee Reducing butt - welding Tee

PIPE FITTINGS (COUPLINGS)

Full coupling

Reducer: Join two different diameters of pipe

PIPE FITTINGS (CROSS CONNECTION)

CROSS: used to connect four pipes together

WELDING FITTINGS (REDUCING FITTINGS)

WELDING FITTINGS

Butt- welding cap

To close the end of the pipe

Flat closure

PIPE FITTINGS (SCREWED UNION)

TYPES OF FITTINGS

900 male elbows 450 male elbows

TeeUnion cross

NIPPLES, COUPLING AND UNION

Nipples and Couplings are used to connect pipes permanently.

Nipples have a male thread but couplings have a female one.

CAPS AND PLUGS

1 .Caps and plugs are used to plug (close) pipe ends

2 .Plugs are having external thread

3 .Caps are having internal thread

FLANGES

Flanges

When the tube diameters are larger than the diameters of the

largest fittings, steel pipes are joined by flanges .

The steel pipes with a small diameter can also be fit with flanges

depending on the nature and pressure of the transported fluid.

TYPES OF FLANGES

Connection to the pipe

1 .Welding-neck

2 .Slip on

3 .Screwed

4 .Blind

5 .Lap joint

6 .Socket-welding

1 .WELDING – NECK FLANGE

2 .SLIP ON FLANGE

3 .SCREWED FLANGE

5 .LAP – JOINT FLANGE (WITH STUB – END)

Stub end Lap joint flange

6 .SOCKET-WELDING

FLANGES

Flanges are permanently identified by die marking to designate:

1. Manufacturer

2. Size

3. Class

4. Material Specification

5. Heat Identification

6. Production Code (Optional)

TYPES OF FLANGE FACES

1 .Flat face flange

2 .Raised face flange

3 .Male & female flange

4 .Ring joint flange (RTJ)

TYPES OF FLANGE FACES

Flat face flange

Raised face flange

Metal ring joint face flange (RTJ)

FLANGE FACES1. FLAT FACE FLANGE

1 .The flange face is completely flat .

2 .Both flanges to be coupled are identical.

3 .The gasket must be of the disc type, entirely contained within the

diameter of the bolt holes or, more commonly, of the full-face

type and the bolt holes punched out.

4 .These require a very wide gasket, and are not suitable for high

pressures.

1 .FLANGE FACES - FLAT FACE FLANGE

Flat face flange (FF)

Gasket for flat face flange

FLANGE FACES1. FLAT FACE FLANGE

Flat face flange

Flat face flange gasket

FLANGE FACES 2. RAISED FACE FLANGE

1 .The two flange faces are identical.

2 .The gasket rests against the raised face.

3 .The purpose of the raised face is to ensure uniform distribution

of pressure over the gasket.

4 .Coupled flanges can easily be separated since the external part

is placed so as to permit the application of tools and wedges.

2. RAISED FACE FLANGE FACES

Raised face flange (RF)

3 .FLANGE FACES – MALE AND FEMALE FLANGE FACE

Large male and female flange

3 .FLANGE FACES – MALE AND FEMALE FLANGE

Large tongue and groove flange

4 .FLANGE FACES – RING JOINT FLANGE

Ring-joint flanges (RTJ)

SPECIAL FLANGES

1 .Blind flanges

2 .Spectacle blind flanges

3 .Orifice flanges

SPECIAL FLANGES 1. BLIND FLANGE OR END BLIND

These flanges are used only for closing lines and valves

SPECIAL FLANGES1. BLIND FLANGE

These flanges are used only for closing lines

It is inserted between two flanges

SPECIAL FLANGES2. SPECTACLE BLIND

1 .These flanges are used to keep the line open or close

2 .It gives indication if the line is open or closed

3 .It is inserted between two flanges

1. Spectacle blind

2. Flanges

3. Gaskets

4. Stud bolts

SPECIAL FLANGES2. SPECTACLE BLIND

SPECIAL FLANGES3. ORIFICE FLANGE

SPECIAL FLANGESTHE WORKING PRINCIPALE OF ORIFICE

For this kind of flanges:

1.The orifice disc must be installed in the correct direction

2.The holes in the flanges must be cleaned every time

3.The gaskets must be replaced

Orifice plate

SPECIAL FLANGES1. ORIFICE FLANGE

For this kind of flanges:

1.The orifice disc must be installed in the correct direction

2.The holes in the flanges must be cleaned every time

3.The gaskets must be replaced

1. Orifice disc2. The orifice disc hole3. Holes to connect the instrument system

FLANGE RATING

The ratings defined by the following:

150 pounds: corresponds to a maximum allowable pressure of 150

psig (pound per square inch gauge) at 500°F (260°C) for all

materials

300 pounds: max allowable pressure 300 psig at 850°F (454°C) for

carbon steel

600 pounds: max pressure (P=600psig) at the same temperature as

the 300 lbs rating

FLANGE RATING

The ratings defined by the following:

900 pounds: max pressure (P=900psig) at the same temperature as

the 300 lbs rating

1500 pounds: max pressure (P=1500psig) at the same temperature

as the 300 lbs rating

2500 pounds: max pressure (P=2500psig) at the same temperature

as the 300 lbs rating

FLANGE RATING CLASS 150

ORIFICE FLANGE UNIONS

GASKET SELECTION

The factors influencing the

choice of gasket are as follows:

1 .Nature of the fluid

2 .Pressure and temperature

3 .Forces acting on the junction

location

Gasket Softness

TYPES OF GASKET

Type of gasket Type of face System pressureC.A.F (Compressed Asbestos Fiber)

Flat face (full face)Raised face (Disc type)

Spiral wound Raised face Moderate

Metal ring R.T.J (Ring tore joint) High

Spiral wound with and without Inner ring

Metal ring gasket (Reinforced) graphite gasket

Non-metallic gasket

TIGHTENING SEQUENCE

PIPE EXPANSION &

EXPANSION JOINTS

What is the function of expansion joints?

It is used to provide some flexibility

1 .The flexibility could be in axial direction to accept the thermal

expansion

2 .Flexible rubber joint is used also to eliminate transmission of

vibration

PIPE EXPANSION

EXPANSION LOOPS

The expansion loop can be fabricated from lengths of straight pipes and elbows welded at the joints

SLIDING JOINT

These are used because they take up little room, but it is essential

that the pipeline is rigidly anchored and guided in strict

accordance with the manufacturer’s instructions; otherwise

steam pressure acting on the cross sectional area of the sleeve

part of the joint tends to blow the joint apart in opposition to the

forces produced by the expanding pipe work (see the following

figures).

Misalignment will cause the sliding sleeve to bend, while regular

maintenance of the gland packing may also be needed.

SLIDING JOINT

EXPANSION JOINTSSLIDING JOINT

The draw back for this sliding joint

1.Misalignment will cause the sliding sleeve to bend,

2.Regular maintenance of the gland packing also needed.

OTHER DESIGNS TO OVERCOME PIPE EXPANSION

U - shape in horizontal plane

Z - shape + expansion joints

EXPANSION JOINTS

COLOUR CODING OF RIGID PIPES

Colour coding is used to indicate potential hazards associated with

the contents of a rigid pipe .

The goal of such marking is to make the task easier for the

technicians, to facilitate intervention by safety crews in event of

damage and to thus prevent any confusion.

80Example of colour codes

COLOR CODES

Some fluids have a specific colour called the secondary identification

colour .

This colour is placed in several places, along the whole length of the

main identification colour .

This colour specifies some of the fluid’s properties :

–Pressure, Temperature, Purity

Indicating the direction of the flow can prove very useful to

quickly locate the block valves in case of an emergency .

A white or black arrow (so as to ensure a better contrast with the

background colour) is placed in the direction of the flow .

For two-way flows, a double arrow is used .

84Direction of the flow

It is often recommended to explicitly attract the personnel’s

attention to the hazardous nature of certain fluids.

Therefore labels, plates, writings or icons are attached to the piping

close to the main background colour.

Examples of pictograms

General warning Explosive materialsSubstances under pressure

Pipe Fittings (Piping Systems)

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