eni spa

exploration & production division

COMPANY SPECIFICATION

TRANSPORTATION AND GATHERING PIPELINES.

MONOLITHIC INSULATING JOINTS

00300.PLI.COR.SDS
Rev. 5 - December 2011

ENGINEERING COMPANY STANDARD

This document is property of Eni S.p.A. Exploration & Production Division.

It shall neither be shown to Third Parties not used for purposes other than those for which it has been sent.
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 3 of 21

FOREWORD

This Revision, N. 5, involves the whole Document.

In particular:
− Norms reference (National, International and Company Standards) were updated;

− Design requirements for insulating joints have been improved, in particular with reference to the conveyed
fluids;
− Design requirements for insulating spools have been introduced, in particular for the calculation of the spool
length,
− The design and manufacturing of monolithic insulating joints have been extended to all materials for pipeline
construction, including also the case of mixed joints;
− For the requirements for insulating joints to be used in sour environment, reference has been made to the
applicable international norms and Company standards;
− All the Informative Annexes have been eliminated and the relevant contents moved within the Document;
− The Data Sheets annexed to this Document have been revised.
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 4 of 21

INDEX

TRANSPORTATION AND GATHERING PIPELINES MONOLITHIC INSULATING JOINTS ......... 1

1. GENERAL......................................................................................................................... 5
1.1 SCOPE.............................................................................................................................. 5
1.2 REFERENCES.................................................................................................................. 5
1.2.1 Codes and Standards ....................................................................................................... 5
1.2.2 ENI Company Standards .................................................................................................. 6
1.3 ATTACHMENTS ............................................................................................................... 6
1.4 DEFINITIONS ................................................................................................................... 6

2. INTRODUCTION............................................................................................................... 7
2.1 PIPELINE ELECTRICAL ISOLATION .............................................................................. 7
2.2 THE MONOLITHIC INSULATING JOINTS....................................................................... 7
2.2.1 Types ................................................................................................................................ 7
2.2.2 Design parameters............................................................................................................ 8
2.3 MONOLITHIC INSULATING JOINTS WITH SPOOL ....................................................... 8
2.3.1 Insulating spool ................................................................................................................. 8
2.3.1.1 Spool length ...................................................................................................................... 9

3. DESIGN FABRICATION MATERIALS .......................................................................... 11

3.1 DESIGN .......................................................................................................................... 11
3.2 FABRICATION ................................................................................................................ 12
3.3 MATERIALS.................................................................................................................... 12
3.3.1 Metallic materials ............................................................................................................ 12
3.3.2 Non-metallic materials .................................................................................................... 13
3.4 COATING........................................................................................................................ 14
3.5 MARKING ....................................................................................................................... 15
3.6 SPECIAL REQUIREMENTS FOR PACKING, SHIPMENT AND STORAGE................. 15

4. TEST AND INSPECTION ............................................................................................... 16

4.1 GENERAL ....................................................................................................................... 16
4.2 VISUAL INSPECTION DURING MANUFACTURING .................................................... 16
4.3 PRELIMINARY TESTS ................................................................................................... 16
4.3.1 Electrical resistance test ................................................................................................. 17
4.3.2 Measurement of coating dry film thickness..................................................................... 17
4.3.3 Coating holiday test ........................................................................................................ 17
4.3.4 Coating adhesion test ..................................................................................................... 17
4.4 ACCEPTANCE TESTS................................................................................................... 17
4.4.1 Electrical resistance test ................................................................................................. 18
4.4.2 Hydrostatic pressure test ................................................................................................ 18
4.4.3 Hydraulic fatigue test ...................................................................................................... 18
4.4.4 Test for electric resistance verification............................................................................ 18
4.4.5 Applied voltage test......................................................................................................... 18
4.4.6 Electric insulation test after immersion in electrolyte ...................................................... 19
4.4.7 Weld inspection............................................................................................................... 19
4.4.8 Inspection of bevelled edges .......................................................................................... 19
4.4.9 Checks of forged materials ............................................................................................. 20
4.4.10 Dimensional checks ........................................................................................................ 20
4.4.11 Final visual inspection..................................................................................................... 20

5. DOCUMENTATION ........................................................................................................ 21
5.1 BID DOCUMENTATION ................................................................................................. 21
5.2 PROJECT DOCUMENTATION ...................................................................................... 21
5.3 TEST DOCUMENTATION .............................................................................................. 21
5.4 FINAL DOCUMENTATION ............................................................................................. 21
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 5 of 21

1. GENERAL

1.1 SCOPE

The scope of this Company Standard is to provide the requirements for the supply of monolithic
insulating joints to be installed on pipelines, including flowlines and trunklines, for their electrical
isolation.

Insulating joints are considered with nominal diameter up to 48 inches and ANSI/ASME pressure
rating from 150 up to 1500.

In particular, the following issues are covered:

− insulating joint types and pipeline isolation;
− insulating spools;
− design and fabrication construction requirements;
− inspection and testing;
− documentation.

The present Document deals with monolithic isolating joints only. Other devices for electrical
isolation, in particular isolating flanges consisting of non-metallic sleeves and washers, are outside
the scope of this Document.

1.2 REFERENCES

1.2.1 Codes and Standards

Ref. /1/ UNI 11105 Giunti isolanti monoblocco PN100 per il trasporto di fluidi combustibili.
Condizioni tecniche di fornitura (in Italian only).
Ref. /2/ EN ISO 8501-1 Preparation of steel substrates before application of paints and
related products -- Visual assessment of surface cleanliness. Part 1:
Rust grades and preparation grades of uncoated steel substrates and
of steel substrates after overall removal of previous coatings.
Ref. /3/ EN ISO 2808 Paints and varnishes. Determination of film thickness.
Ref. /4/ ASTM D 4541 Standard Test Method for Pull-Off Strength of Coatings Using
Portable Adhesion Testers1.
Ref. /5/ EN-10204 Inspection documents for the delivery of metallic products.
Ref. /6/ API 5L Specification for Line Pipe.
Ref. /7/ API 5LC Specification for CRA Line Pipe.
Ref. /8/ ANSI/ASME B 16.5 Pipe flanges and flanged fittings.
Ref. /9/ ASME Sect. V Nondestructive examinations.
Ref. /10/ ASME Sect. VIII Div. I Boiler and pressure vessel code. Pressure vessels.
Ref. /11/ ASME Sect. IX Welding and brazing qualifications.
Ref. /12/ ASME B 16.25 Butt welding ends for fittings, flanges and valves
Ref. /13/ ASTM A 105 Standard specification for carbon steel forgings for piping
applications.
Ref. /14/ ASTM A 370 Standards methods and definitions for mechanical testing of steel
products.
Ref. /15/ ASTM D 709 Specification for laminated thermosetting materials.
Ref. /16/ ASTM D 1000 Testing pressure-sensitive adhesive coated tapes used for electrical
insulation.
Ref. /17/ ASTM D 2000 Standards classification system for elastomeric materials.
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 6 of 21

Ref. /18/ ASTM E 213 Standards practice for ultrasonic examination of metal pipe and
tubing.
Ref. /19/ ASTM E 562 Volume fraction by systematic normal counting.
Ref. /20/ ASTM G 48 Standards test method for pitting and crevice corrosion resistant of
stainless steel and related alloy for the use of ferritic chloride solution.
Ref. /21/ DNV-OS-F101 Submarine Pipeline Systems.
Ref. /22/ MSS SP 44 Steel pipe line flanges.
Ref. /23/ ISO 15156/NACE MR0175 Petroleum and Natural gas industries – Materials for use in H2S
containing environments in oil and gas production.
Part 1 General principles for selection of cracking resistant materials
Part 2 Cracking resistant carbon and low alloy steels
Part 3 Cracking resistant CRAs
Ref. /24/ NACE TM0187 Evaluating elastomeric materials in sour gas environments.

1.2.2 ENI Company Standards

Ref. /25/ 02555.VAR.COR.PRG Internal corrosion. Corrosion parameters and classification of the
fluid.
Ref. /26/ 20603.MAT.COR.PRG Guidelines for material selection in oil and gas processing facilities.
Ref. /27/ 05489.MAT.COR.SDS Additional requirements for pressure vessels for applications in H2S
containing environments.
Ref. /28/ 20000.VAR.PAI.FUN Protective coating, galvanizing and metallizing for internal and
external surfaces of offshore and onshore structures and related
components.
Ref. /29/ 20601.MAT.GEN.PRG Elastomer selection guidelines.

1.3 ATTACHMENTS

Ref. /30/ MOD.COR.CPS.010 Monolithic insulating joints. Technical Data sheet (TDS).
Ref. /31/ MOD.COR.CPS 110 Monolithic insulating joints. Inspection Data Sheet (IDS)
Ref. /32/ MOD.COR.CPS.210 Monolithic insulating joints. Documentation Data Sheet (DDS).

1.4 DEFINITIONS

COMPANY The Company responsible for the issue of the Purchase Order.

SUPPLIER The organization to be awarded a Purchase Order for supply of the

materials and services covered in this Document.

MANUFACTURER The organization responsible for the manufacture of the materials

covered in this Document (not necessary the SUPPLIER).
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 7 of 21

2. INTRODUCTION

2.1 PIPELINE ELECTRICAL ISOLATION

The monolithic insulating joint is a factory prefabricated component, ready to be fitted on a pipeline,
designed to interrupt the electrical continuity but maintaining its mechanical characteristics. It is built
with a metallic central body, containing the isolating and seal materials, and two pipe pups.

Electrical isolation allows the cathodic protection of the pipeline and ensures an effective distribution
of the protection current.

Insulating joints are typically installed:

− in the gathering and distribution flowline networks; the joints are installed in correspondence of the
wells and at manifolds;
− in on-land pipelines, at their extremities and along the pipeline route, for instance at compression
or pumping stations;
− in subsea pipelines, at sea shore and at top of the riser – above water level.

Monolithic insulating joints are preferably installed above ground; alternatively, they can be installed
underground in accessible chambers.

2.2 THE MONOLITHIC INSULATING JOINTS

2.2.1 Types

The central body of the monolithic insulating joint is formed by the metallic flanges and by the shell
assembled by welding; different assembly configuration exist as illustrated in Ref. /1/ (Par. 4).

In this Document, two weld assemblies for monolithic insulating joint are considered:
− Type A (Figure 2.1), with non radiographable weld: to be applicable for design pressure up to
10200 kPa (600 lbs rating);

− Type B (Figure 2.2), with radiographable weld: to be applicable for all design pressures.

B A

37° 30’
C

Figure 2.1 – Type A monolithic insulating joint.

eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 8 of 21

B A

37° 30’
C

Figure 2.2 – Type B monolithic insulating joint.

2.2.2 Design parameters

The design and fabrication of monolithic insulating joints shall be performed considering the project
and environmental factors as detailed in the Data Sheet MOD.COR.CPS.010 (Ref. /30/).

In particular, the following factors and parameters shall be considered:

− design pressure;
− design minimum and maximum temperature;
− pipeline conveyed fluids;
− mechanical stresses and vibrations due to normal operation;
− risk of fire and explosion.

As far as the conveyed fluid is concerned, the following data shall be considered (see also the ENI
Company Standard 02555.VAR.COR.PRG, Ref. /25/, for internal corrosion and fluid corrosivity):
− type of fluids:
− dry gas;
− wet gas;
− liquid hydrocarbon;
− water: sea water; fresh water; formation water;
− glycol;
− other.
− presence of contaminants: H2S; CO2; other;
− sour service conditions as per ISO 15156/NACE MR0175 (Ref. /23/);
− electrical conductivity (for electrolytes).

2.3 MONOLITHIC INSULATING JOINTS WITH SPOOL

Insulating joints to be installed on pipelines conveying liquids with electric conductivity shall be
delivered completed with a pipe segment, or insulating spool, of adequate length.

2.3.1 Insulating spool

The insulating spool shall be installed on pipelines handling:

− any type of water;
− multiphase systems containing a free liquid water phase.

The aim of the insulating spool is to create an ohmic voltage drop between the two extremities of the
joint sufficient to prevent the circulation of interference current through the conveyed fluid. This is the
case of insulating joints installed on pipelines and separating one side with impressed current
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 9 of 21

cathodic protection and the other side not protected (as it occurs for instance with insulating joints
installed on flowlines in the wellhead area).
The insulating spool shall be installed on the pipeline protected side, i.e. the side receiving the
interference current circulating inside the joint.

The length of the insulating spool shall be calculated based on the diameter of the insulating joint and
the resistivity of the conveyed fluid.

The insulating spool shall be manufactured form pipes of same material, grade, diameter and
thickness as the pipeline the joints will be connected. The insulating spool shall be internally coated.

2.3.1.1 Spool length

The insulating spool length is the main parameter to limit the maximum current value that by-pass the
joint and consequently the internal corrosion rate.
1
By means of cell balance calculations, the following equation is obtained for the minimum length of
the insulating spool (LSPOOL):

D
L SPOOL = 5
ρ

where:
D [m] pipeline diameter
ρ [ohm·m] electrolyte resistivity

Calculated minimum length of the insulating spool as a function of internal diameter and electrolyte
resistivity are reported in Table 2.1.

1
Considering the effect of the coating efficiency of the internal insulation of the spool, a more conservative formula can be
obtained, as illustrated in Luciano Lazzari, Pietro Pedeferri, “Cathodic Protection”, Polipress Ed. 2006 (Paragraph 5.10).
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 10 of 21

ρ = 0.2 Ω·m ρ = 2 Ω·m ρ = 20 Ω·m

Diameter D (in.)
LSPOOL LSPOOL LSPOOL
2” 2.5 0.8 0.3
2”1/2 2.8 0.9 0.3
3” 3.1 1.0 0.3
4” 3.6 1.1 0.4
5” 4.0 1.3 0.4
6” 4.4 1.4 0.4
8” 5.0 1.6 0.5
10” 5.6 1.8 0.6
12” 6.2 2.0 0.6
14” 6.7 2.1 0.7
16” 7.1 2.3 0.7
18” 7.6 2.4 0.8
20” 8.0 2.5 0.8
22” 8.4 2.6 0.8
24” 8.7 2.8 0.9
26” 9.1 2.9 0.9
28” 9.4 3.0 0.9
30” 9.8 3.1 1.0

Table 2.1 – Insulating spool minimum length as a function of diameter and electrolyte resistivity.
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 11 of 21

3. DESIGN FABRICATION MATERIALS

3.1 DESIGN

The design of monolithic insulating joints shall be in accordance with ASME Section VIII Div.1
Appendix 2 (Ref. /10/), conveniently adapted.

Monolithic insulating joints shall be designed for the pressure defined by ANSI/ASME B16.5 (Ref. /8/)
for the pressure rating of the pipeline where the joints shall be installed. Pressure rating and design
temperature are indicated in the Data Sheet MOD.COR.CPS.010 (Ref. /30/).

In this Document, Insulating joints are considered with nominal diameter up to 48 inches and
ANSI/ASME pressure rating from 150 up to 1500. Correspondence between pressure rating ANSI
Class and Nominal Pressure (PN) are the following:

ANSI Class Rating Nominal Pressure

150 20
300 50
400 64
600 100
900 150
1500 250

The electrical resistance of the monolithic insulating joints shall be maintained and guaranteed for the
design life of the pipeline.

Infiltrations of the conveyed fluid into the internal parts of the insulating joints shall be avoided.

The sealing gaskets shall have adequate sizes and shall be fabricated in one piece.

The sizes of the spacer rings, insulating gaskets and filling material shall guarantee the electrical
resistance as specified at Par. 4.3.1.

The length of the pipe pups shall be such that the non-metallic components (spacer ring, sealing
gasket and filling material) would not reach a temperature exceeding 60 °C during the field welding
operations. For high thickness pipelines, tentatively above 25 mm, the Manufacturer shall verify and
confirm that the length of the joint is adequate for the post weld heat treatment of the field welds, with
no detrimental effects on non-metallic components of the joint.

Lengths of insulating joint are given in Table 3.1 for different range of pipe diameters and pressure
rating.

Design of the joint shall be compatible with pipeline pigging operations.

Pipe ASME CLASS RATING

diam.(in.)
150 300 400 600 900 1500
up to 14 700 700 1,000 1,000 1,000 1,000
16 to 24 1,000 1,000 1,200 1,500 1,500 1,500
26 to 36 1,500 1,500 1,800 2,000 2,000 2,000
38 to 48 2,000 2,200 2,200 2,500 2,800 2,800

Table 3.1 – Length, in mm, for monolithic insulating joints.

eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 12 of 21

3.2 FABRICATION

The assembly of insulating joints shall be done in a controlled, clean environment.

Monolithic insulating joints shall be assembled so that the internal (non-metallic) components are
tightly fixed in the required positions.

The number of welds shall be limited as much as possible.

All welds shall be in accordance with ASME Sect. IX (Ref. /11/).

Weld test procedure shall be in accordance with ASME Sect. V (Ref. /9/).

All joints shall be butt welded and have full penetration except for final closure weld. Final closure
weld shall comply with ASME Section VIII (Ref. /10/) Div.1 ULW 17.6.

Welding, weld repair and test procedures shall be approved by the COMPANY Representative prior
to fabrication.

The joint sleeve interstices shall be sealed with suitable elastomeric material in order to prevent
entering of humidity from outside.

Insulating joints without sealing gasket are not acceptable. Moreover, in finished joints the gasket
shall permanently maintain the residual elasticity so that a perfect tightness is guaranteed. Gaskets
shall be enclosed completely into the sleeve.

After completion of the requested acceptance tests, insulating joints will be prepared with bevelled
ends in accordance with ASME B16.25 (Ref. /12/).

3.3 MATERIALS

3.3.1 Metallic materials

The pipe pup used for the insulating joint and the insulating spool shall meet the same design
parameters and fabricated with the same material as the pipe to which the insulating joint will be
connected (see Ref. /6/ and Ref. /7/). The metallic parts of the joint body shall be forged that comply
with requirements and characteristics of the connected pipeline and relevant fittings.

Construction materials for insulating joints include:

− carbon and low alloy steel;
− austenitic stainless steel (type UNS 31603 or 31653);
− martensitic stainless steel (type UNS 41008);
− duplex stainless steel (type UNS 31803 and 31260);
− Ni base alloys (type UNS 08825).

In addition insulating joints can be designed and manufactured also with different pipe pup materials
(mixed joints), e.g. one pipe pup of carbon and low alloy steel and the other of corrosion resistant
alloys.

Insulating joints to be assembled on clad pipeline, shall be preferably designed and manufactured
using solid corrosion resistant alloys, same or compatible with clad material.

For sour service applications, metallic materials and welding shall comply with requirements of ISO
15156/NACE MR0175 (Ref. /23/).
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 13 of 21

Carbon and low alloy steel insulating joints to be used in sour environments, in addition to ISO
15156/NACE MR0175, shall comply with the ENI Company Standard 05489.MAT.COR.SDS (Ref.
/27/); in particular, requirements shall be respected for:
− chemical composition, Carbon Equivalent and Pcm parameter;
− SSC and HIC testing.

Special requirements may be added in the Project Documents.

3.3.2 Non-metallic materials

Insulating spacer ring, sealing gasket, filling material shall have the following characteristics:
− mechanical properties appropriate to service temperature and pressure;
− fluid swelling resistance;
− chemical resistance to any of the fluid in contact with service (also air if present);
− thermal stability at all service temperatures.

The compatibility of all plastic materials which are in contact each other should be verified on
samples before the joint fabrication. The mechanical properties of plastic materials shall be checked
on test samples before fabrication of the joint.

For sour service conditions elastomeric materials shall comply with NACE TM 0187 (Ref. /24/).

Insulating ring

The insulating spacer ring shall be made with rolled epoxy resin reinforced with glass, ageing
resistant, in accordance with ASTM D709 (Ref. /15/), type IV group G10, having high dielectric
characteristics.

Resistance to compression stress shall be greater than 400 N/mm2.

Sealing gasket

The sealing gasket shall be made with suitable elastomer (i.e. butadiene/acrylonitrile copolymer and
fluorine composed rubber) in accordance with ASTM code D 2000 (Ref. /17/).

In Table 3.2 the performance properties and the application limits of main elastomers used for
sealing gaskets are reported (Ref. /29/).

SERVICE
TEMPERATURE MAIN
ELASTOMER H2S RESISTANCE REMARKS
APPLICATIONS
TMIN (°C) TMAX (°C)
Oil Poor Most common oilfield
NBR −30 +120 Natural gas
(Max. H2S=0.01%) elastomer
Water
Oil Fair
Natural gas Often replaces NBR for
FKM −10 +200 (Max H2S=15% and Tmax=150 °C)
Wet gas (sour) heavier services
Water (Max H2S=5% and Tmax=200 °C)
Oil Excellent thermo-
Natural gas Good chemical resistance;
FFKM −15 +230
Wet gas (sour) (Immunity to degradation by sour gas) poor mechanical
Water properties below 0°C.

Table 3.2 – Performance properties and the application limits of elastomeric materials.
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 14 of 21

NBRs are generally not recommended for service in solvents with high aromatic content (>5%),
halogenated hydrocarbons, acetic acid, peroxides, organic and phosphate esters or strong acids.
Amine corrosion inhibitors and zinc bromide brines may also have very serious hardening effects.

FKMs are susceptible to amine based corrosion inhibitors as amines are curing agents of these
elastomers and may cause hardening and embrittlement. Primary and secondary amines are
particularly aggressive. The damage normally occurs very rapidly when temperatures are higher than
90°C and/or the inhibitor concentration is higher than 0.5%.

FFKMs are claimed to be immune to degradation by sour gas; however the FFKM polymers are
susceptible to physic-chemical attack by pressurized sour gas. Mechanical damage is the greatest
threat to FFKM seals in sour service especially in dynamic applications.

Filling material

The filling material shall be an adhesive sealing elastomeric material or thermoplastic resin, lattice
cold forming, low viscosity, having resistance to compression stress greater than 150 N/mm2.

3.4 COATING

After all required tests and inspections have performed, finished insulating joints and spools shall be
internally and externally coated.

Coating systems shall be as much as possible in accordance with ENI 20000.VAR.PAI.FUN (Ref.
/28/).

For carbon and low alloy steel insulating joints to be installed on pipelines with operating temperature
up to 80 °C, internal coating shall be solvent-less epoxy, selected as per Paint System N. 019, 020,
021 and 023 for internal coating, external coating shall be solvent-less epoxy N.024, as per ENI
20000.VAR.PAI.FUN (Ref. /28/):
st
N. 019 * 1 coat: epoxy primer 50 µm
2nd coat free solvent epoxy 300 µm
Total NDFT 350 µm

N. 020 1st coat: epoxy phenolic 100 µm

2nd coat epoxy phenolic 100 µm
3rd coat epoxy phenolic 100 µm
Total NDFT 300 µm

N. 021 1st coat: pure epoxy 150 µm

2nd coat pure epoxy 150 µm
Total NDFT 300 µm

N. 023 1st coat: solvent free epoxy Phenolic 400 µm

Total NDFT 400 µm

N. 024 1st coat: HB epoxy 1500 µm

Total NDFT 1500 µm

*: for fresh water only

For temperature above 80 °C and for materials different from carbon and low alloy steels, the Paint
System shall be selected among those covered by ENI 20000.VAR.PAI.FUN.

Use of zinc rich primer is not allowed.

Coating shall be applied up to 50 mm about from bevelled ends.

eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 15 of 21

Coating application shall be performed after welding completion.

Above coating requirements are also applicable for the insulating spool.

3.5 MARKING

The following information shall be reported on a little plate fitted with glue on the external surface of
each insulating joint which has been accepted (stamps and punching on pipe surfaces are
forbidden):
− project normative;
− VENDOR name or trade mark;
− type of material and grade of steel;
− max. design pressure, in kPa;
− max. design temperature, in °C;
− internal diameter of the pipe segments;
− nominal thickness of bevelled ends;
− number of Purchase Order.

3.6 SPECIAL REQUIREMENTS FOR PACKING, SHIPMENT AND STORAGE

All joints shall be accurately packed in order to prevent damages during transportation, in
accordance with the packing specification issued for the specific project.

Moreover the following cares must be observed:

− the ends of the pipe segments should be plugged with wood or plastics disks and the welding
bevels accurately protected;
− the joints should be transported and stored in vertical position with the jaw sealed by mastic and
turned downwards;
− joints transportation facilities shall provide a closed or tended protection;
− the content shall be indicated clearly on the packing.
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 16 of 21

4. TEST AND INSPECTION

4.1 GENERAL

The VENDOR is requested to submit its own Inspection Test Plan, complete with the list of test
equipment, for COMPANY approval.

VENDOR shall have its own system for inspection, checks and testing, suitable to assure the
conformity of the joints to this specification and to all applicable documentation.

The COMPANY reserves the right to send his own Representative at the Manufacturer workshops at
any time during the fabrication.

If during inspections and testing nonconformities would be verified, production shall be stopped
immediately and will not restart until these nonconformities will be removed.

Tests not witnessed by the COMPANY shall be adequately documented by VENDOR in order to
allow all necessary and possible inspections and verifications.

The tests shall be carried out at MANUFACTURER’s workshop or at an external laboratory

appointed by the VENDOR/MANUFACTURER. COMPANY’s Representative can request at his
discretion samples of the used material in order to arrange the execution of all laboratory tests he
should consider necessary.

If not otherwise indicated in the Project Specifications, tests shall be performed at ambient
temperature between 10 and 35 °C.

Tests and testing, requested to be witnessed, shall be indicated in the Inspection Data Sheet (IDS)
MOD.COR.CPS.110 (Ref. /31/).

All material and test certificates for the above testing and inspection shall meet EN 10204 (Ref. /5/)
and be submitted to the COMPANY prior to shipment.

All joints shall be subjected to the following test and inspections:

− visual inspection during manufacturing (see 4.2);
− preliminary tests on finished joints (see 4.3.);
− acceptance test (see 4.4).

4.2 VISUAL INSPECTION DURING MANUFACTURING

During the manufacturing and assembly of the insulating joints, the COMPANY’s Representative
shall verify that:
− all used materials and components comply with the requirements of this specification;
− assembly and welding operations and surface preparation are carried out fully in accordance with
this Document and with the approved construction drawings.

4.3 PRELIMINARY TESTS

On the insulating joints ready for testing, the VENDOR shall perform the following preliminary tests,
also in absence of COMPANY’s Representative:
− electrical resistance test;
− measurement of coating dry film thickness;
− coating holiday test;
− coating adhesion test.
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 17 of 21

4.3.1 Electrical resistance test

The measurement of the electrical resistance, or insulation resistance, is performed on each

insulating joint, using a mega-ohmmeter, at voltage of 1000 V of applied continuous current.

The measured resistance shall be at least 5 Megaohms. Ambient test temperature and relative
humidity shall be reported on test certificate.

If the joint shows electrical resistance below the required value it shall be dried again and re-tested.
One re-test only is allowed.

4.3.2 Measurement of coating dry film thickness

The coating dry film thickness (DFT) shall be measured in accordance with EN ISO 2808 (Ref. /3/),
Test Method 2 or 3, in at least 5 points conveniently spaced.

The measured DFT thickness shall be of 350 µm minimum and the coating shall resist to the voltage
applied for the continuity test.

4.3.3 Coating holiday test

Test of continuity shall be carried out with a detector (Holiday detector) equipped with a flat wiper and
adjusted for a voltage of 2.5 kV at least (test voltage shall be preliminary verified with the coating
supplier).

No holidays are allowed. All detected discontinuities shall be repaired according.to the project
specification and coating repair procedures.

4.3.4 Coating adhesion test

Adhesion test shall be carried out in accordance with ASTM D 4541 (Ref. /4/) using adhesion gauges
as defined by the std. with the following requirements:
type II, minimum adhesion 5 MPa
type III or type V, minimum adhesion 10 MPa.

Coatings which show insufficient adhesion must be removed by gritblasting. Afterwards a new
coating material shall be applied.

4.4 ACCEPTANCE TESTS

The following acceptance test shall be performed on each insulating joint:

− electric resistance test;
− hydraulic fatigue test;
− hydraulic pressure test;
− test for electric resistance verification;
− applied voltage test;
− electric insulation test after immersion in electrolyte;
− weld inspection;
− dye penetrant test of bevelled edges;
− dimensional check;
− final visual inspection.

All test instruments, gauges and equipment shall be calibrated and the calibration certificates verified
by the COMPANY’s Representative.

Before and during the tests, no leaks are allowed from the welds or connections of the test circuit. In
case a leak is detected, it shall be repaired and the test repeated.
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 18 of 21

The joints shall be tested in series, connected by welding and a slope for draining shall be provided.

The joint ends (or the ends of series of joints) shall be closed with test disks; butt welded and
designed according with ASME VIII Div. I (Ref. /10/) to resist to the test stresses.

No rubber hose and fitting are allowed in the test circuit.

4.4.1 Electrical resistance test

Before the execution of the hydraulic fatigue tests the joint shall be subjected to electric resistance
test (see 4.3.1).

4.4.2 Hydrostatic pressure test

The hydrostatic test shall be carried out on each joint at the hydrostatic test pressure specified in the
Data Sheet MOD.COR.CPS.010 (Ref. /30/).
Where the test acceptance is to be based on 100% visual inspection the holding time at test pressure
shall be until 100% visual inspection is complete or 2 hours, whichever is longer.
Where the test acceptance is to be based on pressure observation the holding time at test pressure
shall be not less than 2 hours.
The pressure test shall be acceptable if:
— During a 100% visual inspection there are no observed leaks and the pressure has at no
time during the hold period fallen below 99% of the test pressure. 100% visual inspection shall
only be acceptable where there is no risk that a leak may go undetected due to prevailing
environmental conditions, or
— The test pressure profile over the test hold period is consistent with the predicted pressure
profile taking into account variations in temperatures and other environmental changes.

4.4.3 Hydraulic fatigue test

Hydraulic fatigue of each insulating joint shall be performed. The test shall consist of 40 consecutive
cycles with the pressure changed from 10 bars to 85 percent of the hydrostatic test pressure
specified in the Data Sheet MOD.COR.CPS.010 (Ref. /30/).
At the completion of the test cycles the pressure shall be increased to the hydrostatic test pressure
and maintained for 30 minutes. There shall be no leakage or pressure loss during the test.

4.4.4 Test for electric resistance verification

After execution of the hydrostatic tests, the joints shall be subjected to electric resistance test (see
4.3.1).

Electric resistance tests, carried out after hydrostatic tests, shall be performed after releasing the
joints from the test disks (and separating the joints if connected in series), and a complete drying of
same joints both externally and internally with hot air.

4.4.5 Applied voltage test

After the electrical resistance test, each insulating joints shall be submitted to the applied voltage
test.

A voltage up to a final value of 2.5 kV, at frequency of 50-60 Hz, shall be applied to the joint placed in
vertical position.

This maximum voltage value must be reached from a value not exceeding 1.2 kV in a time interval
longer than 30 s and maintained for 60 s.
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 19 of 21

The value of the applied voltage and the entity of the leakage current shall be measured continuously
during the test.

Test equipment will include a transformer and a manual device for current regulation; the transformer
should be suitable to supply a secondary current no lower than 0.1 A at maximum voltage. The
voltmeter, to measure the applied voltage, shall be connected on the secondary circuit of the
transformer.

Superficial or disruptive discharges shall not occur during all test duration.

4.4.6 Electric insulation test after immersion in electrolyte

This test shall be performed on one joint only for each lot of joints with same diameter; the joint to be
tested is randomly selected from the lot.

The joint shall be immersed in a 3% sodium chloride (NaCl) solution for 48 hours and then washed
with fresh water and dried accurately.

The electrical resistance is measured as per Par. 4.3.1 immediately after drying and after 5 hours;
measured electrical resistance values shall be:
− 1 Moegahm or greater after drying;
− 5 Megaohm or greater after 5 hours.

4.4.7 Weld inspection

All non-destructive tests of welds shall be carried out consistently with written procedures complying
with ASME Sect. V (Ref. /9/).

All longitudinal and circumferential welds shall be radiographed for their entire length.

For dielectric joint of type A, all radiographable welds shall be radiographed. Welds not
radiographable shall be inspected by ultrasonic or magnetic particles.

For dielectric joints of type B, all welds shall be radiographed.

Sensitivity and acceptance / rejection criteria shall be in accordance with ASME Sect. V (Ref. /9/)
Article 2, if not otherwise stated in the Inspection Data Sheet (IDS) MOD.COR.CPS.110 (Ref. /31/).

Insulation joints shall not be accepted if one of the following types of defect will be found:
− cracks;
− insufficient penetration or incomplete melting;
− undercuts greater than 0.35 mm of depth and 25 mm of length;
− single gaseous spheroidal inclusions with diameter greater than 1.6 mm and/or porosity
concentration with diameter of 1 mm, in number of 6 per 4 cm2;
− contiguous groups of two or more inclusions with diameter greater than 1 mm shall be separated
at least by 100 mm of non-defective material;
− extended porosity exceeding 3 mm of width or 1.6 mm of depth or 6 mm of length.

4.4.8 Inspection of bevelled edges

The bevelled edges of pipe pups, prepared for field welding, shall be examined by ultrasonically
inspected in accordance with ASTM E 213 (Ref. /18/) to detect any rolling defect or other metal
discontinuities within a pipe length of 50 mm from the pipe edge.
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 20 of 21

The following are not acceptable:

− rolling defects in the base material greater than 100 mm in whichever direction;
− discontinuities producing echoes with an amplitude greater than 75% of the screen usable height
and a length greater than 2.5 mm;
− discontinuities producing echoes with an amplitude range from 20% to 75% of screen usable
height and a length greater than 40 mm.

4.4.9 Checks of forged materials

All forged material shall be submitted to dye penetrant or magnetic particles tests in accordance with
ASTM A 105 (Ref. /13/).

4.4.10 Dimensional checks

Bevels and tapering, as also the final length of the joints which have passed positively the specified
tests, shall be checked accurately in order to verify if everything is in accordance with the relevant
construction drawings.

The following tolerances shall be checked:

− internal diameter: measured at both joint ends it shall not vary more than ± 1.6 mm of the nominal
diameter;
− ovalization: for a distance of 100 mm from both ends, the difference between the requested
internal diameter and the measured minimum internal diameter shall not exceed 0.6 % and the
difference between the requested internal diameter and the measured maximum internal diameter
shall not exceed 0.6 %;
− wall thickness: the negative tolerance shall not exceed 0.35 mm for pipe thickness lower than 10
mm and 0.5 mm for thickness of 10 mm or greater;
− longitudinal deviation: the deviation from a right line shall not exceed 0.15 % of the joint length
measured on two directions at 90 degrees each other.

4.4.11 Final visual inspection

All surfaces shall be free of incisions, dents, burning and any other defect.
eni spa 00300.PLI.COR.SDS
Rev. 5 - December 2011
exploration & production division
Sh. 21 of 21

5. DOCUMENTATION

The SUPPLIER shall send to the COMPANY all documentation listed in the Required Documentation
Data Sheet (RDDS) MOD.COR.CPS.210 (Ref. /32/).

5.1 BID DOCUMENTATION

The SUPPLIER shall present along with its offer all documentation relevant to the combined test of
internal pressure and flexion of the joint as well as that one relevant to destructive test or dielectric
resistance carried out on the prototype joint, during the homologation process.

5.2 PROJECT DOCUMENTATION

The SUPPLIER shall send to the COMPANY all documentation necessary for the project
implementation and for all components installation.

The documents, which shall be sent for approval, should include at least the following information:
− construction drawing of insulating joints and spools;
− specification for welding qualification (WPS and PQR);
− calculations/verifications of stresses;
− material specification for forged materials, insulating spacer ring, sealing gasket, filling material,
coating and lining;
− assembling procedure.

5.3 TEST DOCUMENTATION

Test documentation shall include at least the following information:

− list of tests, checks and inspections to be performed;
− procedures for the execution of the tests and inspections to be carried out on materials and
components as requested in the Inspection Data Sheet (IDS) MOD.COR.CPS.110 (Ref. /31/).

5.4 FINAL DOCUMENTATION

Final documentation shall include at least the following information:

− project documentation, issued for approval and approved by the COMPANY;
− installation instructions;
− maintenance hand-book (preventive maintenance instructions, periodical inspection program);
− certificates of tests and checks performed on materials of each component.