Table of Contents

  1. Purpose
  2. General
  3. Availability of Forms and Procedures
  4. Basic Inspection Duties
  5. Other Inspection Duties
  6. Inspection Procedure - General
  7. Welding
  8. Non Destructive Testing
  9. Hydrotest
  10. Coating
  11. Final Inspection
  12. Static Process Equipment
  13. Rotating Process Equipment.
  14. Piping Fabrication and Valves
  15. Structural Steel.
  16. Electrical Equipment
  17. Instruments
  18. References


The purpose of this guide is to inform the Inspector regarding the extent of his reporting in relation to the assigned inspection level for purchase orders and requisitions in general, and assist in the performed inspections and tests by giving guidelines and specific information per type of equipment and materials.

2. General

Company requisitions for materials and equipment are prepared by the engineering departments.

2.1 Based on the requisition, the purchase order and the available Vendor information, the Manager Inspection assigns the inspection level, and prepares the inspection schedule for the project. (See Reference 18.1)

2.2 This inspection schedule reflects all purchase orders for the project and its assigned inspection levels.

The inspection level shall be one of the following:

R - Resident Inspector

IPC - Close prgressive inspection

IP - Progressive inspection

F - Final inspection

N - No inspection

2.3 When necessary, the inspection level can be modified. This change can be initiated by the Inspector, the Manager Inspection or the Project Manager.

2.4 For all inspections the procedure for inspection activities shall be followed. See Reference 18.1.

2.5 The inspection level gives details regarding the scope of inspection. The following Table (2.6) is a guideline for the scope of inspection and the different reports in relation to the assigned inspection level. Regarding the levels and the timing of inspection the following should be considered:

R - Resident Inspection. All intermediate inspection steps shall be monitored closely for the duration of residence. Residence Inspection is implemented for the whole or only part of the manufacturing period, when required contractually or when in the opinion of the Manager Inspection:

  • - the workload in one location warrants it;
  • or when it is necessary to ensure specified quality requirements are met.

IPC - Close progressive inspection. Selected intermediate inspection steps shall be followed according to the inspection and test plan.

IP - Progressive inspection. Limited intermediate inspections shall be witnessed according to the inspection and test plan. Other inspection points will be monitored.

F - Final inspection. Only final inspection shall be carried out.

N - No inspections carried out.

2.6 Inspection Level and Required Reports


Required reports

Form No.






Inspection/Expediting Assignment







Pre-inspection meeting






Progressive inspection






Final inspection







Non Conformance Report







Quality Control Memorandum







Inspection Release Note







  1. Inspection/Expediting Assignment is only used when an outside agency is employed.
  2. A common form 25009 is used to report the various types of inspection visits to the Vendor, the section headings in the text being adjusted accordingly.
  3. Each type of form used shall be numbered 001, 002 etc. per purchase order, the number being followed by the inspectors initials.

3. Availability of Forms and Procedures

All existing reports/forms and applicable procedures can be found in Reference 18.1.

Additional copies can be made available.

4. Basic Inspection Duties

Normal Q.C. (inspection) duties for projects are outlined in par.6, but will also include the following:

4.1 Check the Vendor's understanding of the Purchase Order requirements concerning materials, fabrication testing and inspection by the means of a pre-inspection meeting (See Reference 18.1)

4.2 Check if Vendor furnished documents according to requisition and procedures have been approved by Company Home Office.

4.3 Check, witness or monitor fabrication and testing according the inspection and test plan, in particular respecting holdpoints.

4.4 Check all relevant documentation such as certificates, test reports etc.

4.5 Check manufacturing data books.

4.6 In case of deviations contact the procurement and or engineering department(s) for formal decisions.

5. Other Inspection Duties

Inspectors will carry out surveys on Vendors' shops when required in order to determine Vendors' capabilities, experience and acceptability for work on Company projects, or re-surveys of Vendors shops if a considerable time has elapsed since the last experience with a particular shop.

This is one aspect of the overall assessment of Vendor capabilities and performance conducted by several Company departments. See Reference 18.2.

Inspectors will also continuously advise Company's Home Office on shop-loading developments in Vendors plants, trends in quality of workmanship, performance, etc. to assist buyers in selection of Vendors for new work.

6. Inspection Procedure - General

This section covers basic activities for inspection of all equipment, parts of equipment or parts of package units covered by Company purchase orders. Additional information regarding specific inspections can be found in the following sections, where possible requirements inspections and test are split up per type of equipment and materials.

It must be remembered that it is the Vendor himself who is in the first place responsible for the quality of his work using his own quality system. The inspector works through the Vendor system and would only assume a more pro-active role in case of necessity, and in agreement with the Manager Inspection.

Inspector’s visits to sub-Vendors shall only normally be carried out accompanied by a representative of the Vendor. The Inspector shall not give direct instructions to the sub-Vendor.

Each inspector has a personal rubber stamp with his name and boxes marked “witnessed” and “checked”. He shall use this on each quality record, ticking in one or other box, signing and dating it.

6.1 Acceptance Criteria/Governing Documents for Inspection

6.1.1 The basis of acceptance or rejection is defined by the purchase order requirements including the purchase order itself, the requisition, in combination with referenced codes, standards, specifications and drawings.

6.1.2 In case of contradiction in or incompleteness of the requirements, the inspector shall contact the Manager Inspection.

6.1.3 Vendors' shop drawings are only valid for details and dimensions not included in Company documents.

6.1.4 In the event of contradiction between Company and Vendor documents, Company documents govern unless specified by Company in writing.

6.1.5 Authority requirements shall prevail over Company general and project specifications, unless Company or project specifications are more stringent than the authority requirements.

6.2 Pre-Inspection Meeting (PIM) with Vendor

6.2.1 When applicable a complete review shall be made of the Purchase Order and its attachments, in order to confirm Vendor's proper understanding of all design, fabrication, inspection, and document requirements.

Every effort shall be made to eliminate questions in the earliest possible stage in the execution of the purchase order.

A PIM shall be held in accordance with reference 18.1, and reported on form 25009.

6.3 Material Delivered to Vendor's Shop

6.3.1 For major suborders the Inspector shall check in the first place that they have been placed with previously Company approved sub vendors. He shall then check that relevant requirements expressed in the Purchase Order have been mentioned on the sub-order. These could include:

  • Company Purchase Order number and item number
  • material specification and any special test requirements
  • certification requirements
  • critical minimum dimension
  • excess materials for tests
  • inclusion of clause concerning the Contractor's and Client's inspection rights
  • marking requirements

The Inspector will receive the relevant unpriced copies of suborders together with the Manager Inspection's recommendation for inspection coverage at source.

6.3.2 The type of materials shall be checked if required by PMI, marking of materials shall be identified against certificates as early as possible after arrival of materials at the Vendor's works.

6.3.2 The type of materials shall be checked if required by PMI, marking of materials shall be identified against certificates as early as possible after arrival of materials at the Vendor's works.

6.3.3 The dimensions and appearance shall be checked, paying particular attention to:

  • critical minimum dimensions
  • radii of bending, forging and pressing on manufactured parts
  • fabrication and handling damage to surfaces and edges

6.3.4 The material certificates shall be legible and suitable for xerox copying and shall specify the test results in accordance with the specified material standard. Normal expected statements are the following:

  • name of manufacturer and factory symbol. (as on material)
  • purchase Order number and date of revision
  • manufacturer's order number
  • certificate registration number and date of issue
  • material specification
  • dimensions
  • quantity and/or weight in kg
  • surface examination statement
  • charge number, batch number or heat-lot number
  • chemical composition from test results
  • mechanical properties from test results
  • when applicable, NDT methods and results
  • when applicable, heat treatment procedure, furnace charge number and heat treatment records
  • signatories and function
  • supplementary or additional requirements as specified in the material specification, project specification purchase order as applicable.

Certificates checked and accepted by the Inspector shall be marked with his personal stamp and noted "checked" together with his signature and the date. Unless otherwise instructed the inspector shall only mark his stamp on the first page of the certificate.

6.4 Fabrication Procedures and Qualifications

6.4.1 The Inspector shall verify that all necessary approvals from Company's Home Office and Authorities have been obtained on Vendor furnished procedures and other documents. This can include the following:

  • vendor drawings/data sheets
  • welding procedures and qualifications
  • stress relief and other heat treatment procedures;
  • all forming operations, either hot or cold, on materials other than plain carbon steel
  • tube rolling procedures and rolling sequences
  • non-destructive testing procedures.

6.4.2 The Inspector shall ensure that welders are qualified to the used welding procedures and qualifications.

6.5 Intermediate Inspections

Basically all intermediate inspections either from Vendor, Company or Independent Authority are laid down in the inspection plan. The inspector shall incorporate the assigned inspection level when marking up the hold points in the inspection plan. The advised legend for marking up the inspection plan is as follows:

R - Review
W - Witnesses
H - Holdpoint

This legend can also be used when completing the inspection report.

Examples of hold points in the manufacturing stage are the following:

  1. receipt material inspection;
  2. location and dimensions of cut-outs before cutting;
  3. fit-up of nozzles or other connections;
  4. full dimensional and visual inspection before heat-treatment and/or pressure testing, including acceptance of NDE;
  5. witness insert of bundle for heat-exchangers;
  6. pressure testing; leak testing; PMI on final fabricated equipment and any other special NDE method;
  7. shotblasting/coating/lining;
  8. final inspection; manufacturing data book including shipping provisions or any other transport requirements;
  9. witness transport and/or reloading of equipment.

Regarding possible holdpoints the next chapters (6.6 thru 6.16) give keywords as a reference for use during the inspections. For welding see Chapter 7.

6.6 Receipt Inspection

  • suborder
  • special tests
  • certification
  • minimum wall thickness
  • marking
  • storage

6.7 Location and Dimensions on Cut-outs

  • approved drawings
  • reference lines
  • shell course marking
  • hand or machine cutting
  • restamping material on cut-out for tests
  • weld configuration
  • template available
  • start points of cutting.

6.8 Fit-up of Nozzles/Shell Courses

  • applied welding procedure
  • proper grinding and cleaning
  • NDE for surface defects
  • NDE for weld edge (U.S.)
  • high-low
  • distortion prevented
  • orientation, elevation and stand-out
  • material for fit-up
  • cladding.

6.9 Dimensional and Visual Inspection

  • approved drawings
  • tolerances
  • level indicators; fixed tolerances
  • base plate template on jobsite required in advance
  • proper measuring equipment
  • PWHT to be carried out
  • field connections
  • flange facings and protection
  • internals to be installed
  • sharp edges on nozzles and clips
  • clip dimensions
  • trial fit up of vessels shipped in two or more parts for site welding
  • trial fit up of attachments (ladders; platforms etc.).

6.10 Insert of Bundle

  • dimensions of shell (straightness and ovality)
  • dimensions of bundle
  • proper tackwelding
  • number of baffle plates
  • dummy available
  • grease allowed
  • internal grinding
  • internal cleaning

6.11 Heat Treatment

  • procedure available
  • type of oven, fuel type, avoid direct flames
  • No. of thermocouple and temperature registration
  • calibration of used equipment
  • distortion prevented
  • method of support, expansion is approximately
    CS 1,1 mm/m/100°C
    SS 1,55 mm/m/100°C
  • sign of chart at start of cycle
  • heating up/cooling down rates
  • open oven at which temperature

6.12 Pressure Testing

  • Procedure available:
  • test medium, pressure and duration
  • flange facings check
  • used gaskets type
  • bolt tensioning equipment required
  • proper blinding off
  • correct bolts/nuts in relation to flanges
  • original bolts/nuts available
  • number of pressure gauges and correct ranges and calibration
  • correct venting
  • block valve
  • environment temperature
  • temperature of test medium
  • use of pressure recorder
  • method of support; position for testing
  • air test reinforcements
  • correct emptying (avoid vacuum!)
  • NDE after pressure testing.

6.13 Leak Testing

  • procedure available
  • equipment and calibration
  • work method
  • false indications
  • medium
  • acceptance criteria.

6.14 Positive Material Identification (PMI)

  • procedure available
  • Company standard specification
  • equipment available
  • detection ranges and identified elements
  • incoming materials and final product
  • welds to be checked/electrodes
  • cladding restoring.

6.15 Shotblasting/Coating/Lining

  • testing methods for profile
  • coating manufacturer data sheets
  • environmental conditions (temperature, dewpoint
  • coating thickness (wet, dry)
  • recoating time (curing of zinc silicates)
  • corners etc. not reached with shotblasting
  • sparktesting of lining (general rule = 9 Volts/micron).

6.16 Final Inspection

  • manufacturing Data Book, early list of contents
  • check Vendor furnished documents list and/or job specification for total contents
  • packing/marking/shipping instructions
  • internal cleanliness
  • anti-corrosion measures (silica gel, nitrogen purge etc.)
  • flange protection
  • marking of "North" line or arrow
  • marking of "Centre of Gravity" (COG)
  • method of lifting (slings or chains etc.)
  • method of transport
  • inform Company traffic department and/or jobsite.

7. Welding

When welding is involved on materials or equipment the following topics have to be taken into account:

  • code or non-code items
  • specifications with additional requirements to code
  • availability of WPS and PQR or requalify?
  • welder and welding operator qualifications
  • materials
  • weldability
  • thickness
  • post weld heat treatment and/or soaking
  • welding processes
  • cladding
  • joining unequal materials
  • vendor experience with welding process
  • in or outdoor welding
  • welding consumable handling
  • environmental conditions (temperature; humidity)
  • cutting process
  • pre-heating
  • proposed non-destructive examinations
  • weld configurations
  • fit-up materials
  • distortion prevention
  • dimensional control.

7.1 Basically the requisition and/or job specifications are the documents where the requirements for welding are laid down. For code items Company will normally require that the Vendor transmits the Welding Procedure Specification (WPS) and the applicable Procedure Qualification Record (PQR).


WPS - Weld configuration + position + consumable + equipment etc. as proposed for welding.

PQR - Record of tests done to prove WPS meets code requirements.

The WPS/PQR will be reviewed by Company Home Office using the same system as for drawings.

7.2 Review Codes

F - Final approved

1 - Approved without comments
2 - Approved with comments (production may start when comments are incorporated)
3 - Not approved (resubmit before start production).

7.3 It should be noted that sometimes Vendors do not have the required PQR to cover the proposed WPS and propose to qualify the WPS on a weld coupon which is attached to the longitudinal seam.

7.4 It is always the duty of Inspector to check whether welders are qualified in accordance with approved procedures (validity qualification records).>

7.5 Except when otherwise stated in the job specifications Company Inspectors do not normally witness welding tests. It is the sole responsibility of the Vendors and the applicable authorities.

7.6 It is the duty of the Inspector to ensure that all welding procedures and their qualifications are strictly adhered to by the Vendor. Note changes in geometry, position and welding process or consumable. For example: a Vendor had his WPS/PQR. approved for the welding of circumferential seams using SAW in 1 G position (on rollers), but is in fact welding with SMAW (hand electrode) in the 2 G position (side). The applicable WPS/PQR should be transmitted to the Company home office, and if necessary be requalified in accor­dance with the required code.

In the following chapters some keywords are given per subject related to welding in general.

7.7 Fit-up for Welding

  • reference lines for dimensional control
  • joint alignment; high/low
  • root gaps
  • shrinkage (= +/- rootgap)
  • fit up material
  • tackwelds in bevel or external (bridge plates)
  • removal of backwelds
  • NDE of tackwelds
  • pre-heating for tackwelds thick materials.

7.8 Distortion Prevention

  • proper stiffening/supporting by spiders, strongbacks etc.
  • number of passes
  • symmetrical welding
  • backwelding
  • pre-setting to reach desired dimension after shrinkage
  • large + heavy nozzle on edge of plate
  • large + heavy nozzle in relatively thin shell plate.

7.9 Pre-heating

  • flame cutting on air hardening materials
  • used method - electric or gas
  • area of pre-heating
  • heating up time
  • minimum and maximum pre-heat temperature
  • minimum interpass temperature
  • cooling method (environment)
  • method of checking temperature.

7.10 Visual Weld Examination

  • porosity
  • starts/stops
  • old tackwelds
  • unequal a-height
  • incomplete filling
  • overfilling
  • run out length
  • weld spatter
  • cracks
  • weld cap finish
  • weaving (max. 2,5 x d electr.)
  • arc - strikes
  • marks from lifting clamps.

7.11 Joints in Clad Material

  • approved welding procedure and qualification
  • bonding of clad material
  • sufficient cut away of cladding
  • transition electrode type
  • clad restoring
  • surface finish
  • PMI on electrodes
  • possible NDE (transition of U/S waves causing misinterpre­tations).

7.12 Post Weld Heat-Treatment

  • type of heat-treatment
  • min/max temperature for material according to specification
  • Method of support
    CS: elongation = 1,1 mm/100°C
    SS: elongation = 1,6 mm/100°C
  • visual and dimensional already 100% accepted
  • type of oven
  • max. temperature variation through whole oven
  • type of fuel and availability
  • position of burners
  • calibrated thermocouples and recorder
  • method of attaching thermocouples
  • minimum:
    1 x on thickest piece
    1 x on thinnest piece
    1 x on test plate
    1 x extra
  • hand or remote controlled oven
  • oxidation of materials
  • any stiffening required
  • heating up time/holding temperature/cooling down time
  • complete recording chart available ( mind the scales )
  • re-check critical dimensions after PWHT.

7.13 Welding Consumables

  • acceptable list applicable (controlas etc.)
  • storage
  • handling procedure
  • quivers required
  • holding ovens
  • special electrodes for project.

8. Non Destructive Testing

  • separate procedure required
  • acceptance criteria
  • type of ndt possible
  • qualification of operators
  • subcontracted NDT
  • NDT after visual acceptance of welds
  • minimum "setting time" after last welding before NDT
  • PWHT involved or not
  • any NDT specified after pressure testing
  • are all welds accessible after fabrication
  • up to date NDT lists
  • own qualified film interpreters or rely on Vendor’s.

9. Hydrotest

Regarding the hydrotest, the following topics have to be considered:

  • hydrotest procedure available/required
  • all NDE completed
  • visual and dimensional acceptable
  • method of support
  • testing liquid temperature
  • testing liquid contamination (chlorides stainless steel)
  • correct gaskets installed (hydrotest gaskets or specified type)
  • bolt tensioning equipment required/applied
  • correct bolting in relation to flanges (DIN flanges with DIN bolting as they are less stiff than ANSI flanges)
  • airpockets prevented
  • correct calibrated pressure gauges and ranges
  • minimum 2 pressure gauges
  • pressure recorder required (calibration)
  • block valve between pump and vessel
  • first pressurise to operating pressure then after setting rise to hydrotest pressure
  • test pressure and minimum holding time
  • pressure difference in two or more compartments
  • during testing note any deformation
  • proper venting after test (vacuum!)
  • drying and cleaning
  • any NDE specified after hydrotest.

10. Coating

Regarding coating and lining following topics should be considered.

10.1 General

  • coating system according to requisition/specification
  • in-house or subcontracted
  • approved manufacturers of paint
  • coating procedure necessary
  • applicable data sheets available
  • maximum operating temperature of equipment in relation to maximum temperature allowable for paint
  • approved coating system on drawings
  • all NDE/PWHT etc. carried out
  • visual and dimensional accepted
  • corners rounded off.

10.2 Shot-Blasting

  • type of grit in relation to material or equipment
  • type of grit in relation to required blasting profile
  • method of checking blasting profile
  • cleanliness of blasting (SA 2; 2-1/2; etc.) standard on site.
  • temperature of surface minimum 5 degrees above dewpoint
  • grit recycled or not (mean particle size)
  • flange facings suitably protected
  • method of support.

10.3 Coating Application

  • correct equipment/nozzle type
  • all dust from shotblasting removed
  • coating consistency
  • coating contamination
  • maximum wet film thickness applied (drips, sags)
  • pre strike difficult areas
  • overspraying time
  • temperature of surface.

10.4 Coating Inspection

  • calibrated coating thickness equipment
  • uniform application
  • proper illumination
  • check minimum 5 points per square metre
  • drips/sags/holidays
  • intermediate thickness
  • total thickness.

10.5 Lining and Lining Inspection

  • applicable specification
  • applicable procedure
  • corner rounded off (min: r = 3 mm)
  • manufacturer’s data sheets available
  • minimum surface temperature
  • method of application
  • check thickness with calibrated equipment
  • spark testing minimum voltage = 9V per micron when no spec. etc. available
  • repair procedure

11. Final Inspection

  • nameplate
  • as built drawing available
  • all possible deficiencies cleared
  • flange facings re-check
  • packing/marking/shipping and invoicing instructions for project issued and complied with
  • all drawings final approved
  • all calculations final approved
  • all procedures final approved
  • transport drawings approved
  • transport/lifting marks on equipment
  • spare parts and interchangeability records and/or cards filled in and transmitted to Company Home Office
  • any other outstanding documents according to vendor furnished documents list from requisition
  • traffic department informed
  • expediting department informed
  • site informed.

12. Static Process Equipment

12.1 Pressure Vessels

12.1.1 Specified code to be applied.

12.1.2 Check requisitions for:

  • applicable code(s) and additional requirements
  • used materials and certification
  • welding procedures and qualifications
  • dimensional tolerances
  • non destructive examinations
  • post weld heat treatment
  • authority inspection
  • pressure testing
  • surface preparation
  • service conditions

12.1.3 Points of specific importance during fabrication:

  • skirt-head connections
  • reinforcement plates
  • clips and supports
  • level and indicators etc.
  • weld test plates
  • rounding off nozzles internally
  • insulation rings
  • davits
  • aligning of internals (tray support rings)
  • welds in heads
  • flange facings
  • marking of tangent-line ( in- and outside )
  • base ring template required?
  • saddle fixed and sliding point
  • positive material identification
  • internal dimensional control " straightness
  • O- thickness measurements.

12.2 Heat Exchangers

Shell and tube-exchangers, double pipe exchangers.

12.2.1 Specified code to be applied.

12.2.2 Check requisitions for:

  • applicable code (s) and additional requirements
  • used materials and certification
  • welding procedures and qualifications
  • dimensional tolerances
  • non-destructive examinations
  • post-weld heat treatment
  • authority inspection
  • pressure testing
  • surface preparation and or lining
  • service conditions

12.2.3 Points of specific importance during fabrication:

  • tube to tube-sheet connections
  • reinforcing plates
  • dimensional control of bundle
  • tackwelds and tie-rods
    check tie-rods for intermediate welds ( if so:NDE )
  • bundle dummy
  • rounding off nozzles internally
  • ovality of shell
  • jack-bolts
  • pulling of bundle
  • lifting of bundle
  • impingement plates
  • partition plate welding
  • weld test plates
  • drilling of tubesheets
  • dimensions stacked exchangers
  • expanding percentage
  • welding and rolling or rolling and welding
  • internal sealing strips for longitudinal baffle type exchangers
  • flange facings
  • positive material identification.

12.3 Airfin Coolers

Airfin coolers with headers of various designs such as plugged with loose covers fully enclosed, welded headers, cast headers with various air control systems etc.

12.3.1 Specified national/international specifications to be applied.

12.3.2 Check requisitions for:

  • applicable codes and additional requirements
  • used materials and certification
  • welding procedures and qualifications
  • dimensional tolerances
  • fin type and manufacturing (tightness and length)
  • non-destructive examinations
  • post weld heat treatment
  • authority inspection
  • pressure testing
  • surface preparation and coating
  • service conditions.

12.3.3 Points of specific importance during fabrication:

  • tube to tubesheet connections
  • welding and rolling or rolling and welding
  • drilling of tubesheet
  • expanding " access for NDE
  • plug type material and plug hole type
  • restamping of tubes (prior to finning)
  • prevent fin damage
  • for structural steel see separate section 15.0
  • fit-up of header boxes
  • welding sequence of header boxes
  • positive material identification
  • O measurements
  • grooving of fin to end 15 mm after tubesheet
  • gasket surface finish for cover type header boxes
  • fabrication of swaged nozzles.

12.4 Heaters

Fired heaters for refinery service.

12.4.1 Specified national/international specification to be applied.

12.4.2 Check requisition for:

  • applicable code(s) and additional requirements
  • used materials and certification
  • welding procedures and qualification
  • dimensional tolerances
  • non destructive examination (castings)
  • post weld heat treatment
  • authority inspection
  • lining requirements
  • pressure testing
  • surface preparation
  • fin type (studs)
  • service conditions.

12.4.3 Points of specific importance during fabrication:

  • welding of hairpins and pipes
  • restamping of pipes
  • postweld heat treatment, supports etc
  • casting technology and pilot castings
  • positive material identification
  • RT acceptance criteria.

    Note: for structural steel see section 15.0

12.5 Atmospheric Tanks

Shop and Field fabricated with fixed roof, floating roof etc.

12.5.1 Specified national/international code to be applied.

12.5.2 Check requisitions for:

  • applicable code(s) and additional requirements
  • used materials and certification
  • welding procedures and qualifications
  • dimensional tolerances
  • authority inspection
  • non destructive examination
  • pressure testing procedure
  • surface preparation
  • service conditions.

12.5.3 Points of specific importance during fabrication (for sake of completeness site erection points included):

  • soil survey
  • soil consistency
  • welding sequences
  • lining " continuous dimensional survey(s) due to settlements
  • automated RT examination
  • fire monitoring system(s)
  • seal for floating roof
  • internal pipes and supports (heaters)
  • trial assemblies
  • gasket surfaces/flange facings
  • internal hoses for draining (roof)
  • skimmers applicable or not
  • floor configuration (cone-down; cone-up; slope)
  • any fixing with anchor bolts
  • clips and structural steel.
    For structural steel see section 15.

12.6 Trays

Trays for site and for shop installation in pressure vessels, reactors etc.

12.6.1 National/international specifications - not applicable.

Manufacturers' standards, e.g. Koch, Glitsch Metawa.

12.6.2 Check requisition for:

  • used materials and certification
  • welding procedures and qualifications
  • dimensional tolerances
  • non-destructive examinations
  • surface preparation such as; (pickling, passivating etc)
  • installation procedure
  • hold down clamps etc
  • filling of loose internals such as balls, catalyst etc
  • service conditions.

12.6.3 Points of specific importance during fabrication and /or installation:

  • dimensional control (especially flatness)
  • trial assembly
  • tray holes, bubble caps, chimneys
  • overlapping edges
  • downcomers
  • bolting down devices
  • marking of tray numbers
  • contamination with other materials
  • positive material examination
  • gaskets between tray and support rings
  • installation through manhole possible
  • spargers.

13. Rotating Process Equipment

13.1 Centrifugal Pumps

Single and Multistage.

13.1.1 Specified national/international specification to be applied.

13.1.2 Check requisitions for:

  • applicable code(s) and additional requirements
  • used materials and certification
  • any welding involved
  • dimensional tolerances
  • seal system
  • accessories
  • used driver
  • baseplate type
  • NPSH and performances
  • service condition.

13.1.3 Point of specific importance during fabrication:

  • balancing of impeller(s)
  • dimensional control
  • installation of seal(s)
  • flange facings finish
  • testing procedure
  • positive material identification
  • non destructive examination results
  • repairs carried out
  • hydrotest procedure and liquid type
  • head/flow testcurve from water calculated to specified liquid
  • aligning pump and driver on base plate
  • protection of couplings etc (coupling guard)
  • grouting of baseplate on site involved
  • vibration measurements
  • flange facings.

13.2 Screw Pumps

13.2.1 Specified national/ nternational specification to be applied.

13.2.2 Check Requisitions for:

  • applicable code(s) and additional requirements
  • used materials and certification
  • any welding involved
  • dimensional tolerances
  • seal system
  • accessories
  • used driver
  • baseplate type
  • performance and other testing requirements
  • service conditions.

13.2.3 Points of specific importance during fabrication:

  • welding of casing
  • machining
  • dimensional control
  • seal installation
  • testing procedure
  • non destructive examination (access!)
  • aligning pump and driver on baseplate
  • baseplate grouting involved on site
  • coupling guards
  • testcurve from water calculated to specified liquid
  • state and/or dynamic balancing
  • vibration measurements
  • flange facings.

13.3 Centrifugal Compressors

Single and Multistage.

13.3.1 Specified national/international specification to be applied.

13.3.2 Check requisition for:

  • applicable code(s) and additional requirements
  • used materials and certification
  • any welding involved
  • dimensional tolerances
  • seal system
  • driver
  • testing requirements
  • seal system
  • accessories
  • baseplate type
  • casting requirements
  • service conditions.

13.3.3 Points of specific importance during fabrication:

  • welding and/or repair by welding
  • casting
  • static and/or dynamic balancing
  • pressure test requirements
  • non-destructive examination
  • aligning compressor and driver on baseplate
  • grouting of baseplate involved on site
  • coupling guards etc.
  • positive material identification
  • testing procedure for impellers overspeed etc
  • record of clearances
  • shop/performance/string test
  • vibration measurements
  • internal examination after
  • flange facings.

13.4 Reciprocating Compressors

13.4.1 Specified national/international specification to be applied.

13.4.2 Check requisition for:

  • applicable code(s) and additional requirements
  • used materials and certification
  • any welding involved
  • dimensional tolerances
  • driver
  • seal system
  • testing requirements
  • seal system
  • accessories
  • base plate
  • service conditions.

13.4.3 Points of specific importance during fabrication:

  • welding and /or repair by welding
  • casting
  • static and/or dynamic balancing
  • pressure testing
  • non-destructive examination
  • grouting involved on site
  • coupling guards
  • positive material identification
  • performance testing procedure
  • alignment of crank shaft
  • other alignments driver/compressor etc.
  • stripping test
  • flange facings
  • "rod run-out" prior to test run.

13.5 Steam/Gas Turbines

13.5.1 Specified National/International Specification to be Applied.

13.5.2 Check requisition for:

  • applicable code(s) and requirements
  • used materials and certification
  • any welding involved
  • dimensional tolerances
  • used as driver for:
  • seal systems
  • testing requirements
  • accessories
  • baseplate
  • service conditions.

13.5.3 Points of specific importance during fabrication:

  • welding and/or repair by welding
  • casting
  • static and/or dynamic balancing
  • pressure testing
  • non-destructive examination(s)
  • performance testing procedure
  • dimensional control/clearances
  • alignments
  • stripping test
  • installation of rotor
  • vibration measurements
  • complete testing procedures:

14. Piping Fabrication and Valves

14.1 Pipespools

14.1.1 Specified national/international code shall be applied.

14.1.2 Check Requisitions for:

  • applicable code(s) and additional requirements
  • used materials and certification
  • welding procedures and qualifications
  • dimensional tolerances
  • non destructive examination
  • post weld heat treatment
  • pressure testing
  • surface preparation
  • authority inspection
  • service conditions

14.1.3 Points of specific importance during fabrication:

  • fit up materials
  • compliance with welding procedures
  • marking, restamping authority
  • keep iso's up to date
  • maintain traceability
  • tracking of NDT records
  • marking of fieldwelds
  • welding of branch fittings and correct fit up
  • flange facing protection
  • O-thickness measurements
  • threaded connections
  • positive material identification:

14.2 Piping Materials

Pipe, fittings, flanges, O-lets, bolts, nuts.

14.2.1 Check requisition for:

  • applicable code and/or specification and additional requirements
  • non destructive examination
  • welding involved
  • heat treatments
  • hardstamping requirements
  • dimensional tolerances
  • service conditions.

14.2.2 Other important notes:

  • approved manufacturers involved to meet code or authority requirements
  • O-lets manufactured in accordance with approved drawings
  • tolerances.

14.3 Valves

Gate, Globe, Check, Butterfly etc.

14.3.1 Specified national/international specifications shall be applied.

14.3.2 Check Requisitions for:

  • applicable codes and additional requirements
  • material and certification
  • welding involved/casting involved
  • non-destructive examination tolerances
  • special packing materials
  • flange facing finish
  • special testing requirements
  • positive material examination
  • any auxiliaries
  • service conditions.

14.3.3 Points of specific importance during fabrication:

  • material marking/tracebility
  • testing procedure
  • control valve settings
  • pilot castings.

15. Structural Steel

15.1 Specified national/international specification shall be applied.

15.1.1 Check requisition for:

  • applicable code(s) and additional requirements
  • materials and certification
  • welding procedures/qualifications
  • non destructive examination
  • tolerances
  • service conditions.

15.1.2 Points of specific importance during fabrication:

  • keep track of all activities
  • (any partial subcontracting for ladders, handrailing etc.)
  • compliance with welding procedures
  • mind large size trusses; nodes (lifting eye etc)
  • inspection per defined lot (shipping lists etc) which is required also for next activities such as galvanising and then arrival at site.

16. Electrical Equipment

16.1 Electric Motors

Three phase, squirrel cage, induction type.

16.1.1 Specified national/international specification shall be applied.

16.1.2 Check requisitions for:

  • applicable code(s) and additional requirements
  • used materials and certification
  • classification zone
  • approved manufacturers
  • specified tests
  • service conditions
  • accessories.

16.1.3 Points of specific importance during fabrication/testing:

  • winding resistance (temperature)
  • insulation resistance
  • bearings
  • vibration tests
  • high voltage test
  • performance test efficiency/power factor/slip

Note: when Cos ø< 0.8 always contact Home Office Engineer

  • thermal constant time (Te time)
  • running up time (Art)
  • pull-up torque
  • rotor inertia (GD2)
  • cooling fan material
  • motor enclosure
  • certification (validity)
  • test of windings
  • terminal box (location and classification).

16.2 Generators

AC 3 phase, air cooled, rotating.

16.2.1 Specified national/international specification shall be applied.

16.2.2 Check requisitions for:

  • used materials and certification
  • service conditions
  • power factor/voltage/frequency
  • accessories (heater, cooling system)
  • bearings.

16.2.3 Points of specific importance during fabrication and testing:

  • temperature rise of stator winding
  • cooling air temperature
  • efficiency
  • momentary excess current
  • overload
  • short circuit requirements
  • voltage variations during operation
  • unbalanced loads
  • wave form
  • overspeed
  • subtransient reactance
  • noise level
  • vibration
  • critical speeds
  • rating plate
  • testing procedure.

16.3 Transformers

Single phase/three phase power and distribution transformers:

  • up to 100 KVA
  • · above 100 KVA.

16.3.1 Specified national/international specification shall be applied.

16.3.2 Check requisition for:

  • applicable code(s) and/or additional requirements
  • used materials and certification
  • classification
  • approved manufacturers
  • specified tests.

16.3.3 Points of specific importance during fabrication and/or during fabrication:

  • full load test for temp, rise of oil 14 quid and HV ILV windings
  • separate source voltage tests
  • overvoltage test (+ increased frequency)
  • no load test
  • winding transformation and polarity test
  • calculation of impedance voltage
  • calculation of iron losses
  • calculation of copper losses
  • calculation of efficiency
  • short circuit impedance
  • dielectric strength of oil or synthetic liquid in transformer
  • earthing.

16.4 Switchgear Switchgear for use in distribution of electrical energy:

  • low voltage switchgear
  • high voltage switchgear

16.4.1 Specified national/international specification shall be applied.

16.4.2 Check requisitions for:

  • specified materials and certification
  • approved manufacturers of components
  • service conditions.

16.4.3 Points of specific importance during fabrication and/or testing:

  • testing procedure
  • circuit breakers
  • protective relays
  • current and voltage transformers
  • fuses
  • draw-out units
  • metering devices
  • inspection of busbars and earthbars, size, connections and hole sizes
  • marking of components (busbars, terminals etc)
  • dielectric test
  • insulation resistance test
  • mechanical interlocks (doors etc)
  • mechanical and electrical operation test
  • interchangeability of components
  • high voltage test for main circuits; control and auxiliary circuits/secondary circuits
  • insulation resistance test
  • grounding continuity test for metal parts of switchboard to main earth bar and switching devices/busbar chambers to main earth bar.
  • shutters test
  • operation test
  • security (screening) for live parts
  • short circuit capacity test
  • impulse test
  • voltage drop test
  • nameplate(s).

17. Instruments

17.1 General

Generally specific test and inspection requirements are stated in the requisitions and/or its applicable documents. Basically the inspection of the instruments will contain a full detailed review of the requisition with applicable documents and a performance test.

This performance test shall be executed for a selected number of instruments, preferably minimum one instrument of each type. The results shall be compared with the calibration/test reports of the Vendor.

17.2 Scope

17.2.1 The following types of instruments will only be inspected if required by the terms of the Purchase Order and its attachments. In this event, the extent of inspection will be agreed between Inspection and Engineering in advance of request for quotation.

(a) Conventional and miniature pneumatic and electronic receiver-indicators, recorders and controllers.
(b) Electronic potentiometer instruments.
(c) Locally mounted indicators, recorders, controllers and transmitters, excluding displacement type level instruments.
(d) Thermocouples and other temperature measuring primary elements.
(e) Minor instruments such as pressure gages, thermometers, rotameters, pressure and level switches etc.

17.2.2 For the above categories of instruments, the Vendor will normally only be requested to furnish certificates of conformity with the specification, unless otherwise specifically mentioned in the Purchase Order.

17.2.3 Prior to release of any instrument for shipping all test calibration and other certificates as required per requisition shall be checked and approved, whether they have been inspected or not.

17.3 For certain specialised instruments as analysers, sample conditioning systems, control panels, auxiliary cabinets etc., inspection (where called for in the requisition) may be jointly with a control systems engineer. In these circumstances the proposed inspection dates, as advised in expediting reports, will be communicated in advance to Engineering.

In some cases it might be requested by Engineering to send instruments which are supplied by others, but actually forming a part of the system, to the Vendor of the system for an integral performance test.

17.4 In-Line Instruments as control valves, orifice flanges, turbine meters etc. shall, in addition to the specific instrument inspection procedure as described in this chapter, be inspected as described elsewhere in this guide.

17.5 Instruments on Package Units The inspection procedure for instruments on package units is identical to the inspection procedure as described above. In addition special attention shall be given to:

  • make and type of instrument
  • range of instruments
  • scale of instruments
  • location
  • visibility/accessibility
  • durability of installation
  • material certification
  • enclosures.

If the instruments are wired/piped by Vendor:

  • type of cable/tubing:
  • armoured/unarmoured
  • thermocouple extension cable
  • size and type of cable glands/unions
  • durable fastening of wiring/tubing

17.6 In some cases relevant Authorities require certain tests and inspections of safety and relief valves or bursting discs. A combination of Company's and Authority inspection shall be considered to improved co-ordination and to facilitate Authority approval.

18. References

  Document number Title Level
18.1 BN-IN-005 Vendor Inspection Procedure 3
18.2 CM-PE-711 Vendor Quality System Requirements 2