Fittings and small bore tubing systems
Contents
1. 24 Fittings 2 5 Installation precautions Work must not be performed on pressurized systems even in the case ot a leak An approved bleed off point must be used for depressurization Do not bleed off the system by loosening a nut or the body of a compression fitting Do not mix materials or different brands of compression fittings tubing ferrules nuts and bodies Always use the customer s recommended thread sealant lubrication on tapered NPT threads Y O LL 25 spulniy 26 Fittings 2 6 Installation procedure Cut the tube with a perpendicular cut 90 degrees a tube cutter is recommended ensure that the tube cutter is in good condition before starting ensure that the cutting wheel is sharp 2 turns do not over tighten since this can result in an oval tube which 1 8 turn will not correctly fit into the fitting two turns with the cutter followed by an approx 1 8 turn ofthe handle Both the ID and OD of tubes shall be deburred after cutting blow through the tube as a final cleaning with compressed air shavings that are left behind can cause turbulence and possibly leaks in sensitive downstream eguipment Fittings 2 6 Installation procedure 3 Install all the components of the compression fitting on the tube Check that all components are present and properly aligned before assembly 0 O2. LL 4 Insert the tube into the compression fitting Make sure that the tube rests firmly on the shoulder of the fitting e use the fitting manufacturer s depth marking tool and a pen pencil to mark the tube at the top of the tool e for the brands Swagelok and Gyrolok this control line shall not be visible when the tube is inserted into the body and the nut is snug tight For the brand Parker A Lok the tool draws a line on the tubing and the line is visible during the entire installation process 21 spud 28 Fittings 2 6 Installation procedure SJ Tighten the nut until the tubing cannot be rotated Mark the nut and body with vertical lines directly above each other with a felt pen Hold the body still and tighten in accordance with the table in chapter 2 page 29 Use the brand manufacturer s inspection tool to verify correct tightening Note The tool only verifies that the fitting is tightened 7 enough It does not register over tightening which is a widespread problem Fittings 2 7 Assembling procedure The table shows the correct tightening procedures for Parker A Lok Gyrolok and Swagelok compression fittings The columns indicate the number of turns after snug tight the tube cannot be turned for different tube dimensions and when manual or hydrau i af lic pre assembly is used 2 E
3. j DA Ze 20 Gyrolok Imperial no shoulder on body indicates imperial long shoulder on nut no groove on front ring Fittings 2 3 Markings Parker A Lok Parker A Lok Metric e shoulder on the nut and on the Parker A Lok Imperial p O LL body e no shoulder e mm is die stamped on body or on elbows nut indicates crosses and tees imperial 21 TI gt O 0 22 Fittings 2 4 Materials The material guality of the fittings body and nut must always be checked for compatibility If the material types of the body and nut differ this must be reported to the technical responsible position for the plant Each brand may have a different way of indicating material guality Never mix components from different brands CD O GO di O 316 Fittings 2 4 Materials 0 O pm LL Swagelok fittings in super duplex stainless steel for example have a recessed edge at the top of the nut for identification The nut and body are marked with SAF 2507 23 Fittings 2 4 Materials Gyrolok uses colour coding on the body and nut as illustrated in the figure below Always check the physical markings on all components spud Do not rely on colour coding alone 6MO Hastelloy Duplex 316ss Titanium p n10CMBDX3ME p n10CM8316ME p n10CMBTIME p n10CM86MOME p n10CM8HCME
4. tape size tape is used for 4 1 8 1 4 and 3 8 tapered AM male parts e 1 2 tape size tape is used for larger tapered male parts comet wa esate E00 39 D Q Q 40 3 3 Tape thread sealant PTFE Procedure for Silver Seal and Swagelok tape 1 Ensure that the threads are clean and free of damage m y 2 Make sure not to apply the tape to the first thread 3 NOTE apply the tape sealant tightly for 2 2 5 turns in the direction of the thread thick type of tape Always check Threads 3 3 Tape thread sealant PTFE the manufacturer s recommendations and procedure Check that the first thread is free of tape because if it is not the tape can loosen and the system become contaminated Cut off surplus tape Press on the overlap so that the tape is pushed down into the threads It is important to ensure that the male connector does not loosen during assembly m Dynamic loads can cause the tape to shrink a bit and this can over time result in leaks N jo V 6 lt 41 gt D 0 Q p 42 3 4 Paste The most common types of thread sealant used in today s tubing systems are Loctite 577 and Loctite 542 Other types and brands can also be used Use only the customer s approved type The following points generally apply when using Loctite products All the parts must be clean and dry befor
5. Tightening 1st Ti Remak E ightening 1st Time emake Size Size 9 J Manual Hydraulic LL mm inches Parker Parker pre assembly pre assembly Alok Gyrolok Swagelok Aok Gyrolok Swagelok HSU 2 1 16 3 4 11 4 3 4 1 8 1 4 1 8 3 LA 3 4 11 4 3 4 1 8 1 4 1 8 3 17mm 4 3 16 3 4 11 4 3 4 1 8 1 4 1 8 6 lad 11 4 114 11 4 va wa 14 6 35mm 10 28 Taim lata lata va ve 1 9 52mm 12 V2 lara lata lata 14 wa 9 12 70mm 5 8 1 1 1 16 sm 14 144 11 4 14 14 1 4 20 aaa lata va 44 14 19 05mm 1 1 1 25 psaomm 1774 114 11 4 14 14 1 4 1 1 4 HSU HSU HSU e 5 8 41 4 412 4 4 14 li 1 1 9 HSU HSU HSU 2 38 10mm 9 8 1 4 1 2 u3 Li L 2 HSU HSU HSU 50 60 80mm 43 4414 412 4 V4 VA e canbeused ee mustbe used Use the correct tool for the compression fitting supplied the fitting brand manufacturer O 29 Fittings 2 8 Preswaging Pre swaging shall be done whenever possible The ferrules are firmly swaged on the tube in advance Pre swaging prevents the tubing slipping out of the body during assembly while tightening and ensures correct installation spud Always follow the brand manufacturer s user manual Oversized tubing max tolerance can occasionally get stuck in the tool after pre swaging If this happens carefully wiggle the tube
6. is used for designing tubing and piping for both process and instruments pipes and tubes 1 tubing 1 piping FO VA Ei tubing measures 1 piping exactly 1 25 4 mm measures 33 4 outside mm outside f E Tubing 4 1 Definition Tubing small bore tubing means tubes with an outside diameter that is less than or equal to 50 mm 2 wall thickness 0 jenba Jo ugy SS9 93 4 Tubing gt SN 4 2 Handling 6 ef ee Tubing 4 2 Handling The surface condition of the tubing is very important for achieving tight connections Longitudinal grooves welding seams scratches or flat sections etc will normally prevent a tight seal The quality of tubing can easily deteriorate if handled carelessly Careful handling from the moment the tubing is received until it is installed is a must in order to achieve a leak free installation Good handling practices will prevent scratches and nicks that could prevent adequate sealing especially on gas lines Tubing must never be dragged across hard surfaces Tubing made of softer materials like copper and aluminium requires extra care If the tubing has been damaged deformed such that it is no longer completely round difficult to insert through nuts rings or bodies it must be recut Never force oval tubing into a compression fitting Preservation Normally tubing shall not be painted However AIS
7. widely used thread types D Q Q 02 External and internal male and female threads must be of the same type If in doubt a pipe thread gauge o and thread gauge must be used 36 3 2 Tapered pipe threads National Pipe Taper NPT Tapered threads are designed to seal in the threaded part A sealing compound must be used on the threads in order for NPT threads to be pressure tight The sealing compound also has a lubricating function that prevents cold welding and galling of threads This can easily happen to stainless steel components Threads Use the sealing lubrication compound paste or tape decided by the customer for the relevant connection i M NN ha JA AAA ae W PRN 37 3 2 Tapered pipe threads National Pipe Taper NPT Components with threads which are pressurized must not be unscrewed Ensure that no one is standing in front of a component when it is being unscrewed even when the system has been depressurized spealyl Threads 3 3 PTFE Tape PTFE tape is the best known Teflon tape It provides lubrication sealing and protection to chemical attacks e g from solvents This is the only organic lubricant permitted for oxygen in gas form The tape supplier s application procedure must be followed N jo V O lt The tape size must be suitable for the size of the Male part of the compression fitting e 1 4
8. I 316 tubing can be susceptible to pitting corrosion in salty atmospheres If AISI 316 tubing has to be used in a salty atmosphere paint can be one way of avoiding pitting corrosion 99 4 Tubing gt Eu 4 2 Handling Tubing must be marked with its size material type guality specification of standard heat number and other information For example 10 00 x 1 50 MM HT 014211 SS LOT 57534 DIN 2931 Outside diameter 10 00 mm Wall thickness 1 50 mm Heat number HT 014211 Material SS Stainless Steel 316 316 L LOT number LOT 57534 Standard DIN 2931 Zu EEE Tubing 4 2 Handling Ensure the tubing chosen is suitable for the relevant process medium temperature and environment As these are ferrule connections they are subject to requirements concerning both tolerances and the hardness of the tubing Always follow the fitting brand manufacturer s requirements Always check the tubing and fittings to identify the material quality These shall have the same material quality unless otherwise has been approved by the technical responsible person The choice of material must be approved by the technical responsible person For example the ferrules in AISI 316 SS fittings cannot be installed in a SAF 2507 Super Duplex tube since Super Duplex is much harder than 316 SS Mixing materials may result in galvanic corrosion due to the galvanic differences between the materials Where the material
9. Norskolje8gass FITTINGS AND SMALL BORE TUBING SYSTEMS Handbook May 2013 Rev 04E Copyright O 2013 Norwegian Oil and Gas Association Design Mintra Trainingportal as Contents 1 Introduction 04 13 2 Fittings 14 33 Table of contents 1 1 1 Qualifications 6 1 2 Course provider 7 1 3 HSE precautions 8 1 4 Work package checklist 9 10 1 5 Execution 11 1 6 Language and use of names 12 13 1 Introduction 1 1 Qualifications It is the employer who is responsible for ensuring that the employees have the skills necessary to perform their work properly The Norwegian Oil and Gas Association has developed a handbook for work with fittings and small bore tubing systems in pressurized systems containing hydrocarbons This can be downloaded from www norskoljeoggass no Training shall be provided in the different makes of compression fittings that are actually going to be used The required qualifications can be listed in the company s own governing documents industry standards or be defined or referred to in the contract between the operator and the contractor between the contractor and subcontractor This enables operationalization of the required skills The handbook covers three makes of compression fittings Gyrolok Parker A Lok and Swagelok However other brands can be used The brand to be used must be decided by the customers for each job The Norwegian Oil and Gas Association provide no guidan
10. back and forth until it loosens The tubing must not be twisted Do not try to loosen it with tongs pliers or other tools since this can destroy the seal surface 30 Fittings 2 8 Preswaging Manual pre swaging tool p O pm LL Hydraulic pre swaging tool 31 Fittings 2 9 Verification of installation Use the brand manufacturer s gauge to verify correct execution Inspection and depth marking tool e ls used to confirm installation has been properly 7 performed z e ls used to ensure the tubing is in contact with the bottom Q of the body e Follow the brand manufacturer s user manual 32 Fittings 2 9 Verification of installation SGAGEM12 1 2 12MM REY NO A A LOK Always use tools supplied by the compression fitting D gt manufacturer p O p LL 33 Table of contents 3 3 1 Threads 36 3 2 Tapered pipe threads National Pipe Taper NPT 37 38 3 3 PTFE Tape 39 41 3 4 Paste 42 43 3 5 Assembly tolerances 44 47 3 6 Parallel pipe threads BSPP 48 49 3 1 Threads There are several types of thread specifications on the market but in general there are two main types parallel and taper Examples of marking on the body 1 NPT NPT or no marking 2 BSPT is marked with BSPT or RT 3 BSPP is marked with BSPP or RS RP or RG On the Norwegian continental shelf NPT and BSPP are the most
11. ce on this 6 H ndbok fittings og tubing Introduction 1 Notes 1 Introduction 1 3 HSE precautions 1 Always maintain a good overview of the work site and who is involved in the work 2 Do not use assemblies that can injure people or damage equipment or tools 3 Use the correct protective equipment such as protective footwear gloves goggles etc 4 Check that there is an approved and signed work permit for the job before starting the work 5 If working at height the work site must be secured to prevent falling objects tools parts etc Introduction 1 1 4 Work package checklist A work package shall normally contain the following 1 A marked up P amp ID or arrangement drawing that shows where the job shall be performed 2 A job specification with the necessary detailed work drawings If expansion loops are required the package shall include ISO drawings of these List of materials Valve and blind lists and or descriptions of the necessary isolation blinding 1 Introduction 1 4 Work package checklist The person responsible for planning the work shall ensure that 1 The correct parts tubing compression fittings etc are available and that they conform to a valid pipe class sheet PCS tube specifications if a PCS has been prepared for the relevant tubing system 2 The necessary tools are available 3 The need for scaffolding and barriers when wo
12. e use New parts should be liberally sprayed with cleaning fluid and this should then be allowed to evaporate for 30 60 seconds before the part is ready for the adhesive to be applied Apply the Loctite all the way around on the first or second thread If too much is applied the Loctite will flow upwards and possibly into the adjoining component tubing Activator must be used as recommended by the product manufacturer At low temperatures applying heat must be considered in addition to the activator to ensure curing Always follow the paste manufacturer s procedures for application and curing 3 4 Paste Never re tighten a nut with cured Loctite paste products The Loctite will break and the risk of cold welding will increase O 0 jo a O lt 43 3 5 Assembly tolerances Threaded pipe fittings plugs and other eguipment with tapered pipe threads must be correctly assembled to avoid leaks and other undesirable events NPT pipe threads must conform to ASME B1 20 1 or API Std 5B and the customer s requirements ASME and API have thread tolerance reguirements that can make it difficult or impossible to install the parts together with the reguired number of threads This can happen with unfortunate combinations of the standards permitted tolerances 1 Ensure that the dimensions and the threads are correct D DO Q Y 2 NOTE some thread types may have the same o
13. ead above the midpoint Threads 3 5 Assembly tolerances If the threads in the female part are chamfered at the entrance the threads are regarded as starting where the chamfering ends gt 0 jo a O lt 47 3 D Q Q 0 3 Threads AS 3 6 Parallel pipe threads BSPP British Standard Pipe Parallel Threads BSPP Parallel threads do not seal in the threaded part It is a metal rubber or plastic sealing ring that creates the seal e g Dowty Parallel threads especially BSPP are increasingly being used in hydraulic and nitrogen applications The DIN 3852 and ISO 228 1 standards stipulate requirements for both the threads and the meeting seal surface 48 Threads 3 6 Parallel pipe threads BSPP Components with threads which are pressurized must not be unscrewed Ensure that no one is standing in D front of a component when it is unscrewed even when the system has been depressurized p O 0 6 read 49 Table of contents 4 4 1 Definition 52 53 4 2 Handling 54 57 4 3 Dimensions and wall thicknesses 58 4 4 Installation 59 61 4 5 Cutting 62 63 4 6 Bending 64 67 4 7 Expansion loops 68 32 aj Tubing AA 4 1 Definition There are no structural differences between tubing and piping The structural calculations for both of them are the based upon ASME B 31 3 This standard
14. ending is in the right direction use a help line Bend the tubing in a controlled manner to the 90 degree mark Check the angle Experience shows that one has to compensate for tensions in the tube approx 1 3 degrees Place the tubing so that the mark lies directly below the 45 degree mark on the hand tube bender Lock the tubing in place in the bender Bend the tubing in a controlled manner to the 45 degree mark Check the angle Always handle tubing with care to avoid scratches and damage D 67 68 aj Tubing AA 4 7 Expansion loops The work package must contain a design drawing of the expansion loops Expansion loops must be designed in conformity with ASEM B31 3 or its equivalent Follow the customer s guidelines company specifications when designing expansion loops The technical responsible person must always be involved in order to clarify how much movement the expansion loops must absorb how big the loop must be and whether any hoses should be used Notes 69 Notes 70 Notes 71 ar AV Norskolje8gass If you have any guestions feedback or comments on the contents of the handbook please contact the Norwegian Oil and Gas Association s technical manager for HSE who can be reached via the switchboard by calling 47 51 84 65 00 www norskoljeoggass no
15. ing can easily be deformed become oval 62 A Ting 4 5 Cutting 3 After every second turn of the cutter tighten the handle by about 1 8 of a turn until the tubing has been cut 2 turns 1 8 turn 4 After cutting remove internal and external burrs with a tool Clean all the metal shavings out of the tubing after removing burrs Too much de burring of the outside diameter may prevent the connection from sealing properly 63 aj Tubing gt Eu 4 6 Bending Always use a bending tool suitable for the tubing s size It is recommended to use a bending machine when bending larger dimensions e g from 20 mm and thick wall tubing It is good practice to measure up mark and bend lengths one at a time Remember to measure from centre line to centre line 1st length and length 3rd length 64 Ting 4 6 Bending 65 aj Tubing AA 4 6 Bending 90 degree bend 1 Place the tubing so that the mark lies directly below the 90 degree mark on the hand tube bender Pr nr 2 Depending on the type of bender this is marked with 90 or U left 3 If your reference measuring point is from the right the R right mark must be used 4 Make sure the O marks on the hand tube bender are directly above each other and lock the tubing in place in the bender 66 Tubinga 4 6 Bending 45 degree bend 1 Make sure that b
16. necessary be protected against careless impacts e g footsteps and ladders e The need for expansion loops must be assessed by a ASME B 31 3 qualified designer Bend tubing before installation if bending is required 59 Tubing 4 4 Installation Imperial Metric T L T Length u mun enat Tune 2 en inches straight tubing inches milimetres milimetres 6 21 1 8 23 32 6 22 9 16 3 4 10 25 1 13 1o ie 29 9 16 Ig 14 31 3 8 19 16 15 22 Vo 13 16 16 32 7 11 4 18 32 20 JO 3 4 1 1 4 22 ae 18 15 16 20 40 1 Vy 28 40 11 2 4 30 52 1 1 9 2 13 30 30 51 2 3 1 4 38 60 60 ST 4 4 Installation L Straight tube length required from end of tube to beginning of bend R Radius of tubing bend as required or minimum allowed for specified wall thickness and tube size as recommended by bender manufacturer T Tube outside diameter 61 4 Tubing AA 4 5 Cutting Tubing must be cut with a perpendicular cut 90 There are two common methods of cutting tubes e Tube cutter e Hacksaw The use of a fine toothed hacksaw in guide block is recommended for dimensions greater than 3 4 20 mm When using a tube cutter 1 Ensure that the cutting wheel is sharp and suitable for the material the tool will be used on 2 Do not over tighten Tub
17. nut e brand on nut and body and body body e brand on both e shoulder on e brand on both ferrules front ring ferrules j a 17 spu Fittings 2 2 Dimensions A compression fitting s dimensions are stated on the basis of the outside diameter of the relevant tubing Compression fitting are available for both metric and imperial tubing dimensions Each brand may have a different way of indicating the imperial inches and metric millimetres dimensions of their fittings The table below shows the most commonly used dimensions in inches and millimetres Size metric Size imperial 3 1 8 3 17mm 6 1 4 6 35mm 10 3 8 9 52mm 12 1 2 12 70mm 16 5 8 15 87mm 20 3 4 19 05mm 25 1 25 40mm 32 1 1 4 31 75mm 38 1 1 2 38 10mm 50 2 50 80mm Never mix imperial and metric components 18 Fittings 2 3 Markings Swagelok Swagelok Metric e shoulder on the o nut and on the A Ww lok Imperial body Swagelo peria e mm is die e no shoulder stamped on on body or elbows crosses nut indicates and tees imperial MN AUN AO vi 4 4 et n Fittings 2 3 Markings Gyrolok r Gyrolok Metric e shoulder on the nut on the body and the groove on front ring e mm is die stamped on bodies nuts elbows crosses and tees TJ O 02 i
18. rking at height has been determined 4 The operating history of the system has been investigated and assessed to ensure that required measures have been planned for and will be implemented 10 10 H ndbok fittings og tubing Introduction 1 1 5 Execution The qualified person who shall perform the work and the equipment responsible person system operator process technician area responsible person shall together ensure that There is an approved work permit 2 A SJA safe job analysis and possibly a pre job briefing has been carried out if required The correct location and connections have been identified Isolation blinding has been correctly performed and the system is unpressurized and free of hydrocarbons 5 Valves that are going to be disassembled are in the half open position or as shown in the valve maintenance manual so that the valve is free of pockets of trapped pressure 6 Any insulation has been removed and heater cables disconnected if relevant for the job 7 The equipment has been secured against unintended displacement during disassembly 1 Introduction 1 6 Language and use of names This handbook covers what are defined as small bore tubing systems e g tubes with an outside diameter OD of less than or equal to 50 mm 2 Small bore tubing is referred to as tubing in the handbook Compression fittings is a collective term for all the parts components that are used
19. s are located in the galvanic series depends on the medium passing through the pipe Any mixing of materials must be approved in advance by the technical responsible person 97 58 4 3 Dimensions and wall thicknesses It is usually the tube s outside diameter wall thickness and material that limits the tubing system s operating pressure However this is not always the case when tube fittings with threads is used The threads are usually the weakest link in a tubing system Tables and piping class sheets pipe tube specifications for outside diameter and wall thickness state the tubing s maximum operating pressure E5 AA NW 4 It is important to plan the tubing arrangement before installation bin a 4 4 Installation Check points for installing tubing e Working drawings shall be available e The tube routing shall not come into conflict with existing equipment Contact the technical responsible person if in doubt e The tubing routing must not block access for maintenance e Tube support must be used on long spans of tube If in doubt check with a ASME B 31 3 qualified designer Imperial Metric Spacing 1 4 1 9 6 12 mm 0 6 m 0 9 18 14 22 mm 0 6 m 1 25mm he Separate tables must be used for imperial and metric tubing Examples of the recommended spacing between tube supports e Tubing must not be used to support equipment e The tubing must if
20. to connect tubing systems Introduction 1 1 6 Language and use of names English Norwegian Instrument og Tubing prosessror Nut Mutter Shoulder Skulder Rear Back ferrule Bakre klemring Front ferrule Fremre klemring Shoulder Skulder Body Kropp MEVA YA ht Table of contents 2 2 1 Twin ferrule compression fitting 16 17 2 2 Dimensions 18 2 3 Markings Swagelok 19 2 3 Markings Gyrolok 20 2 3 Markings Parker A Lok 21 2 4 Materials 22 24 2 9 Installation precautions 29 2 6 Installation procedure 26 28 2 7 Assembly procedure 29 2 5 Preswaging 30 31 2 9 Verification of installation 32 33 spud Fittings 2 1 Twin ferrule compression fittings The most commonly used fitting in tubing systems is a compression fitting with two ferrules Internationally there are more than 30 different brands of this type of fitting The most widely used brands in the Norwegian offshore industry are e Parker A Lok e Gyrolok e Swagelok These three brands are used as examples in this handbook However other brands can be used The brand to be used must be decided by the customer for each job gt Never mix components from different brands Fittings 2 1 Twin ferrule compression fittings Below are shown the identifications used by the three example brands PARKER A LOK SWAGELOK GYROLOK 0 O LL e brand on nutande brand on
21. utside dimensions and thread pitch Different types of threads shall not be mixed 3 Ensure that the threads are free of damage and have smooth surfaces 4 The threads can be refreshed by use of a thread tap or threading die Check that the thread tolerance requirements are fulfilled after they have been refreshed 44 3 5 Assembly tolerances 5 Requirements for fully assembled components with tapered NPT threads are Minimum 4 5 threads must be fully engaged Preferably 5 5 threads or more should be screwed in without permanently deforming the threads p O 0 6 read A 6 The qualified person performing the installation work is responsible for ensuring that the required number of threads have been engaged 7 Contact the immediate superior for further instructions if the engagement reguirements are not achieved The torgue used to sufficiently tighten the assembly must not damage the threads 45 D 0 el 46 3 5 Assembly tolerances The threads can be checked with an ASME API pipe thread gauge before assembly to check that the tolerance requirements conform to the customer s applicable specifications for the parts Tolerance requirements that normally ensure that sufficient threads can be assembled without damaging the parts small male parts and large female parts Male part 1 til 4 thread above the midpoint Female part til 1 thr
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