Section 15 — Inspection

Principles and Practices for Inspection and Testing of In-Plant Refinery Equipment

IPE Engineering Practice IPE-EP-15-4-1

Document number: IPE-EP-15-4-1 · Section: 15 — Inspection

SCOPE

This Practice provides general philosophy and guidance for inspection and testing of static equipment in plant service.
The contents outline principles for inspection and testing and include organizational responsibilities, procedures for equipment registration, frequency of inspection, reporting and recording of inspection activities.
Other Practices in the EP 15–4 series set out detailed procedures for inspection and testing of each equipment type.
Any deviation from this Practice must be approved by the procedure described in EP 1–1–3.
A revision bar indicates all changes made to this Revision.

2.0 REFERENCES

The latest edition of the following standards and publications are referred to herein.

STANDARDS AND PUBLICATIONS

IPE Engineering Practices
EP 1–1–2 Revisions/Additions/Deletions to IPE Engineering Practices EP 1–1–3 Deviations to IPE Engineering Practices EP 7–3–1 Rerating of Pressure Vessels EP 15–3–1 Training, Qualifying and Certifying Personnel for Inspection and Testing of Plant Equipment EP 15–4–2 In–Plant Inspection of Existing Piping Systems EP 15–4–3 In–Plant Inspection of Existing Pressure Vessels EP 15–4–4 In–Plant Inspection of Existing Tankage EP 15–4–6 In–Plant Inspection of Existing Fired Heaters EP 15–4–8 In–Plant Inspection of Existing Stacks EP 15–4–9 In–Plant Inspection of Pressure Relief Valves
API
Std. 510 Pressure Vessel Inspection Code Std. 570 Piping Inspection Code Std. 653 Tank Inspection, Repair, Alteration, and Reconstruction
ASME Codes
Sec I Power Boilers Sec VIII Pressure Vessels, Division 1

STANDARDS AND PUBLICATIONS (Cont.)

National Board of Boiler and Pressure Vessel Inspectors
NB–23 National Board Inspection Code
Code of Federal Regulations
29 CFR 1910.119 Process Safety Management of Highly Hazardous Chemicals

3.0

3.1

3.2

3.3

3.4

3.5

3.6

3.7

3.8

3.9

3.10

DEFINITIONS

Equipment – Static pressure containing equipment within a plant where scheduled inspection and/or testing is required by either company requirements, jurisdictional regulations or industry codes to assure personnel safety, environmental compliance and reliable operations.

Inspection – The examination or examination and physical testing or checking of functional operation.

Inspection Activity – Any of a number of inspection techniques that can be used to evaluate equipment conditions. These include, but are not limited to, visual inspection, any of the routine or specialized NDE methods used in equipment integrity evaluation, field or laboratory metallography, use of corrosion coupons and probes, hardness testing, and mechanical testing of trepan samples.

Inspection Authority – Person(s) competent in the assessment of plant equipment for continued safe operation. The Inspection Authority shall have such experience and expertise as is necessary to clearly identify potential failure mechanisms and define appropriate inspection plants and procedures to ensure failure mechanisms are clearly identified and monitored.

Inspection Grade – A grading of equipment on a scale 0, 1, 2 or 3, to indicate the maximum interval between thorough inspections.

Inspection Plans – A listing of all the inspection activities together with their due dates and intervals that occur within a complete inspection cycle for each equipment item. An inspection cycle will begin with and end with a thorough inspection. The extent of the inspections to be performed under the inspection plan will be defined in the refinery’s inspection procedures as amended by the recommendations from the last inspection.

Management – The person or persons legally responsible for a Plant owned or operated by

IPE Engineering Company. Owner – Inflection Point Engineering, LLC.

Plant Inspector (Plant Integrity Assessor) – The person or persons appointed by management to be responsible to the Static Equipment Inspection Authority for the inspection of equipment within the plant.

Registration – The act of assigning a unique identification number and an individual record file for each item of critical equipment.

Thorough Inspection – A thorough inspection means a careful and critical scrutiny in or out of service as appropriate. This inspection shall meet or exceed requirements established by applicable codes, standards, and jurisdictional or federal requirements. The methods and extent of this scrutiny must be sufficient to satisfy the inspection authority that the equipment is fit for continued service and will enable the person conducting the examination to:
Detect defects or weaknesses in relation to the strength and functions of the equipment being examined and to ascertain its condition.
Measure the rate and identify the type and cause of wear and deterioration.
Collect sufficient data on which to predict future service life for safe, efficient, continuous operation.
Establish the period for which the equipment may be used prior to the next thorough inspection.
NOTE: Thorough inspection of pressure containing equipment, designed to permit entry, will normally require internal inspection.

GENERAL PRINCIPLES

Responsibilities
The inspection of equipment must be given adequate consideration through all the stages from initial design through shop manufacture, site fabrication or erection, commissioning and subsequent operation. This Practice is concerned with the periodic inspection of installed critical equipment, on the assumption that such equipment has been designed, fabricated and installed according to the codes, standards or specifications approved by the Owner.
It is the responsibility of management at each plant to assure that the requirements of this Practice for inspection and testing of in–plant equipment are implemented.
The static equipment Inspection Authority shall have a responsibility for forecasting likely repairs and renewals. Therefore, maximum use shall be made of on–stream inspection and monitoring techniques.
Identification and Registration

All equipment requiring inspection and/or testing shall be identified and registered before being placed into service. The inventory shall include all such items in each plant and there shall be a procedure for updating this inventory when equipment is added, modified, withdrawn from service, or when new inspection requirements are identified.

Records
A file or other suitable permanent record shall be established for each item of equipment that is subject to inspection. This file shall contain all relevant specification data reports made during manufacture, material and other test certificates or details of where these are kept, and shall also contain a record of inspection intervals.
The records must be kept in a safe place with appropriate access to staff responsible for operation maintenance and inspection. Such access may be direct or by computerized information retrieval systems.
Inspection Intervals

The interval between inspections will be governed by local statutory regulations, the nature of the process, the materials of construction, operating conditions, the rate of deterioration of components, the consequences of failure, environmental effects, the age of the equipment and other relevant factors.
This Practice sets out maximum recommended intervals (for each grade) between inspections for the various types of critical equipment. These intervals shall not be exceeded, unless there are sound reasons and technical justification for doing so and management dispensation is granted. Such reasons and justification must be recorded.
Competent Inspection Personnel

Personnel responsible for inspecting equipment must be qualified and trained, as defined in EP 15–3–1 and have such practical and theoretical knowledge and actual experience of the type of equipment to enable them to carry out the examination, and render sound technical judgement.

Reporting

All the inspections shall be formally reported (see paragraph 8.4 of this Practice) and the reports placed in the record file. Management must be alerted to any significant events or changes that may affect the safety or operational efficiency of the equipment, and the need for significant repairs or renewals.

Audit of Inspection Functions

To maintain a consistently high operational standard, inspection functions shall be subject, at intervals no greater than 5 years, to an audit by a team external to the plant appointed by management, so that the management may be assured that inspection responsibilities are being carried out satisfactorily. This team shall provide management with a formal report of the results and any recommendations.

REGISTRATION

Identification

All equipment requiring periodic inspection within the scope of this Practice shall be identified by a distinct and unique identification number. With the exception of piping systems, the identification number shall be stamped or otherwise clearly marked on the equipment.

Records
In addition to the identification of items of equipment (see paragraph 5.1), individual records shall be maintained for each item.
The records shall include the items detailed in paragraph 8.2.
Change of Duty

Where it is proposed to transfer equipment to a different duty the inspection grading must be reviewed. Where a change of operating conditions is proposed, including changes in design throughput, careful consideration must be given to the possible effects on the equipment and the inspection grading confirmed or modified.

Plant Modifications and Repairs

Any proposed modification or repairs to plant or equipment must be subject to a formal system of approval in which the design, fabrication, inspection and test requirements are considered by appropriate specialists. The static equipment Inspection Authority will ensure that the modifications and repairs are carried out in accordance with the required procedure and that complete documentation of all technical details is retained in the records system.

FREQUENCY AND EXTENT OF INSPECTION

General

The intervals which elapse between inspections may be dictated by industry codes, such as API 510, API 570, or API 653 and federal requirements, such as OSHA 29 CFR 1910.119; and/or jurisdictional regulations. In any case, the following shall apply in such a way as to supplement but not interfere or overrule the governing inspection interval requirements.

Equipment may be subject to diverse operating conditions, such that only broad guidance can be given on the frequency of inspection. The choice of inspection frequency can be made only by those persons who are thoroughly familiar with the equipment.
This Practice includes four concepts which are inter–related and from which decisions may be made regarding inspection frequency:
The assigning of Inspection Grades.
The inspection review procedure.
Sample inspection procedures.
The exemption of equipment.
The assigning to Inspection Classes.
These are discussed and explained below.
The assigning of Inspection Grades and Classes, the extent of the inspection review procedure, the acceptance of sample inspection and a change of the Inspection Grade shall be the responsibility of the static equipment Inspection Authority with the provision that the maximum intervals for the particular Inspection Grade must not be exceeded, unless there are sound technical reasons for doing so, noting the special case considerations in Paragraph 6.8. Such reasons must be clearly recorded.
Assigning Inspection Grades

Equipment shall be subject to scheduled periodic inspection and shall be given an Inspection Grade (0, 1, 2 or 3) that indicates the maximum interval that may elapse between thorough inspections (See 6.3, 6.5 and Table 1 and Table 2 ).

Selection of Inspection Grades
General: The following are some of the factors to be considered when determining the Inspection Grade.
Severity of service duty and the consequences of failure of the item.
History of similar equipment in similar duties.
The original design standards, materials and construction.
The age of the item and the length of time it has been in service.
The optimum utilization of components and materials.

Inspection Grade 0 is the Grade in which all ungraded equipment shall normally be assigned, unless Paragraph 6.8.3 applies following the pre–commissioning inspection, and until the initial thorough inspection is carried out and a subsequent Grade is then determined. The recommended maximum inspection interval for Grade 0 may be extended only when, in the opinion of the static equipment Inspection Authority, the maturity of design, operation conditions and the degree of quality control during manufacture are sufficient to justify such an extension.
Inspection Grade 1 shall be assigned when the conditions of service are such that:
Deterioration in whole or in part is possible at a relatively rapid rate or at a known mean rate which restricts service life, or
There is little evidence or knowledge of operational effects on which to predict behavior in service. The inspection interval must be based on a thorough assessment of all relevant factors.
Inspection Grade 2 shall be assigned when the conditions of service are such that:
Deterioration in whole or part has been shown to be at a reasonable and predictable rate, justifying an increased inspection interval, and
Knowledge of facts or actual behavior in service is sufficiently reliable to justify an increased inspection interval.
Inspection Grade 3 shall be assigned when the conditions of service are such that:
A thorough inspection verifies that the item has successfully concluded a period of service in Grade 2,
Deterioration in whole or in part has been shown to be at a low and predictable rate, and
Facts and knowledge of actual service conditions are sufficiently accurate and reliable to justify an increased interval between inspections.
Determination of Inspection Frequency
Each item shall have a pre–commissioning inspection before entering service for the first time.
Each item shall initially be Grade 0 and be subject to its first thorough inspection, following a carefully determined period of service.
Each item shall be subsequently assigned Inspection Grade 1, 2 or 3, on the basis of the criteria in paragraph 6.3 of this Practice.
Grade 3 items shall be subject to an inspection review at appropriate intervals to confirm or modify the findings and recommendations of previous inspections. Note that API 510 requires that pressure vessels be inspected externally at the corrosion half–life but in no case may the interval be longer than every five years. This external inspection requirement may serve as the inspection review point for Grade 3 pressure vessels.
Table 1 and Table 2 provide requirements for the maximum intervals which may be allowed to elapse between:
Pre–commissioning inspection and the initial thorough inspection.
First and subsequent thorough inspections.
Thorough inspection and the inspection review (Except as permitted in paragraph 6.8 for special cases).

An extension beyond the date of the next thorough inspection as stated on the last thorough inspection report may be granted, subject to each case being submitted to, and having the written approval of, management (or a responsible person delegated by management) in consultation with the static equipment Inspection Authority. It is important that adequate records are maintained of the basis on which decisions were made regarding extensions.
Each item shall be assigned a maximum inspection frequency inspection frequency consistent with the maximum for the Grade; however, in some cases it may be more appropriate to assign an inspection frequency that is significantly less than the maximum permitted for the Grade (e.g. equipment that is approaching the end of its remaining service life).
Kinds of Inspection
Initial Thorough Inspection: An initial Thorough Inspection is for the purpose of ensuring:
That the overall design and construction of the equipment, following a period of service under operational conditions, is sound, and that any deficiencies are investigated and corrected.
That standards of fabrication and material quality are fit for their purpose and if not, are corrected.
That all components essential to the integrity of the equipment are examined and measured (or otherwise inspected) and that such measurements (or inspection results) are recorded to form the basis of calculations or assessment of corrosion or wastage patterns for future remaining life predictions.
That repairs or renewals required are identified and notified to the appropriate authorities and the Owner.
That a report, detailing the condition of the equipment is available to management and that they are made aware of its overall condition, repairs or renewals carried out or required, limiting or inhibiting factors and future remaining life predictions.
That the Inspection Grade is reviewed and a date is set for the next thorough inspection.
Subsequent Thorough Inspections: Subsequent Thorough Inspections are essentially follow–up inspections from the initial Thorough Inspection and are for ensuring:
That the equipment and all its essential components or fittings are examined and measured (or otherwise inspected) and that the results of such measurements, examinations or inspections are compared with previous results to enable calculation or assessment of corrosion (or other forms of possible defects) to be made and predictions made on future remaining life.
That repairs or renewals required are identified and notified to the appropriate authorities, including the Owner.
That modifications, repairs or renewals to the equipment are carried out according to the requirements of the applicable design code and the relevant IPE Engineering Practices.
That a detailed report describing the condition of the equipment, its components or fittings is made available to the management, and that they are made aware of its overall condition, any repairs, renewals or modifications carried out or required, limiting or inhibiting factors and future remaining life predictions.
That the Inspection Grade is confirmed (or modified) and a date set for the next thorough inspection.

Sample Inspections:
Where a group of items of equipment are of sufficiently similar design and construction, and subject to similar service conditions such that they may be expected to be subject to similar deterioration, the static equipment Inspection Authority is entitled to accept sample items for thorough inspection. The sampling shall be on the basis shown in Table 4.
In the event of the findings of the sample inspection being unsatisfactory, the static equipment Inspection Authority shall specify Thorough Inspection of further items as appropriate. If the samples selected for inspection are found to be satisfactory, those items in the group which have not been thoroughly inspected shall have an inspection report endorsed to the effect that the item has been passed for service on the results of inspection of a specific item number in this group. At the sample inspection, all factors affecting these items shall be considered. This principle of sampling does not apply to Protective (Safety) Devices.
Inspection Reviews
An inspection review is carried out to determine if there is any evidence to suggest that an Inspection Grade given at the last Thorough Inspection should be changed. It involves carrying out such on–stream inspection as may be possible or necessary, and examining other relevant data which may be available, e.g. from corrosion probe rates, metal contents of effluent streams, operating data, etc.
Equipment shall be subjected to an inspection review when:
Any changes have occurred since the last Thorough Inspection which may lead to a possible shortening of the interval allowed to elapse before the next Thorough Inspection, or
Significant changes take place in the conditions of service of any item of equipment, irrespective of its Inspection Grade, which would affect its deterioration, or
An abnormal incident occurs, which has or could have affected the safety of operation of the item of equipment, or
A special case exists which, in the opinion of the static equipment Inspection Authority and at their discretion, warrants a review irrespective of the Inspection Grade.
Cautionary Note: When making an inspection review, or considering the re–grading of any plant or equipment, full consideration must be given to any changes in feed quality, feed rates, process upsets, cyclic temperature or pressure excursions, and the number of stops and starts during the period up to the review.
In most cases, these reviews should be performed in conjunction with 29 CFR 1910.119 Management of Change procedures. When the static equipment Inspection Authority determines that MOC procedures should be invoked, the static equipment Inspection Authority shall be responsible to notify the appropriate personnel.
Inspection Grade Transfers
The prime requirements when considering the transfer of an equipment item to a different Inspection Grade are:
Inspection intervals shall be chosen appropriate to the needs of the equipment, consistent with a knowledge of the design criteria of that item, its service conditions and its mechanical condition.

Decisions in Grade transfers, intervals between inspections and the extent of inspection and reviews (and any special case considerations noted in 6.8 of this Practice) shall be adequately recorded.
On the basis of the initial Thorough Inspection, an item may be transferred to Grade 1 or Grade 2, providing the inspection has indicated that the conditions for the new Grade have been met. Conversely, and also on the basis of a Thorough Inspection, any item in Grade 2 or 3 may be transferred back to Grade 1 or 2, if the results of the inspection indicate that the conditions for the present Grade are not being met.
When a sample inspection is at the initial Thorough Inspection, the subsequent interval established between inspections for the same group shall not exceed the maximum for Grade 1. When a sample inspection is again applied at a subsequent Thorough Inspection, the interval between inspections may be increased to that for Grade 2 or 3 based on the findings of the initial and subsequent inspection. The elapsed time between any two Thorough Inspections on pressurized equipment shall not exceed the maximum intervals given in the appropriate tables except as permitted in Paragraph 6.4.6.
Special Cases
Replacement Equipment
Exceptions to the normal grading procedure may be applied where a new or replacement item of equipment:
Performs a duty similar in all respects to that of an existing item.
Is substantially the same as the existing item in regards to design, material, and quality of construction.
The new equipment may then be classified and given the same Inspection Grade as the item with which it is being compared.
Mature Design

Where process equipment has such design maturity that its operating conditions and rate of deterioration can be predicted with confidence, an Inspection Grade may be based on the service history of identical items. All documentation relating to the above assessment must be recorded and on–stream monitoring carried out to confirm the basis of the assessment.

Deferred Start–up and Intermittent Operation
Occasionally, process equipment may not be put back into operation immediately following maintenance and Thorough Inspection. As the inspection intervals granted are for a positive expiration date rather than an elapsed operating time, the period out of operation is regarded as equivalent to a period in operation. Should the outage time exceed 6 months, the Plant Inspector shall carry out an inspection review and may, at his discretion, take into account all or some of that time that has expired while the equipment was not in operation. The same approach may be applied to a plant which is run on an intermittent basis, an inspection review shall be carried out if an item of equipment is out of service for more than 50% of any one 12– month period. In both a deferred start–up and intermittent operation, it shall be noted that deterioration can occur at a rate much faster than normal, particularly in the following circumstances:
External corrosion due to damp insulation, on equipment and pipework.

Internal corrosion due to the presence of water and acidic compounds that may not be damaging at higher (operating) temperatures.
Fouling of equipment due to low water flow or stagnant conditions.
The static equipment Inspection Authority shall take all the above and other relevant factors into account when considering whether to change the previous Inspection Grade.

6.8.4 Piping Systems

The principles of grading may not apply to all critical piping systems. For most piping, sophisticated corrosion monitoring programs will effectively and conservatively determine inspection intervals and predict retirement dates. A thorough, integrated program for piping inspection will include on–stream/off–stream wall thickness measurements to monitor internal corrosion and periodic visual examinations to monitor external deterioration. Complete guidelines for piping inspections are included in EP 15–4–2.

6.9 Assigning Inspection Classes

6.9.1 Thorough inspection of pressure vessels and piping shall be performed to the extent necessary to assure the equipment is adequately sound for the intended service. The equipment shall be assigned a classification number 1, 2, or 3, or 4 based on the consequence of failure of the equipment.

Extent Of Inspection
The extent of inspection shall be in accordance with the appropriate API inspection guide as defined within local plant procedures. It is the responsibility of the Inspection Authority to ensure that the extent of inspection required by the Inspection Plan is adequate to ensure the equipment is suitable for continued safe operation. The Plant Inspector shall ensure that the inspection performed complies with the procedures in both extent and quality sufficient to satisfy the Inspection Authority that the equipment is sound the suitable for continued use.
For equipment outside the experience of the Inspection Authority, it may be necessary to involve specialist engineers (e.g. a Corrosion Engineer) to ensure all potential failure mechanisms are considered in preparing the Inspection Plan. The documents defining the extent of a given inspection type will consist of:
The plant generic procedures for the type of inspection to be performed.
Any specific addenda appropriate to the specific equipment or specific type of equipment. Specific addenda will normally be required when an item of equipment is known to be subject to unique type of deterioration or failure mechanism (e.g. stress corrosion cracking) or where specific defects have been found to exist and require to be monitored.
Any recommendations for additional inspection to be performed as a result of the last series of inspections.
Generic site procedures will normally refer to accepted industry guidelines such as:
API 510 for the inspection of pressure vessels
API 570 for the inspection of piping
API 653 for the inspection of above ground storage tanks
National Board Inspection Code for Boiler Inspection

Other equipment may require additional procedures in order to comply with good engineering practice but the principles included in the above documents should be used as a guide.

Inspection of equipment not in process service is optional, unless otherwise determined by the jurisdiction.

7.0

7.1

7.1.1

7.1.2

7.2

7.3

7.3.1

7.3.2

7.4

INSPECTION ORGANIZATION

General

It has been the usual practice for the Owner to employ its own staff for the inspection of equipment. In some cases, for shutdowns or to satisfy statutory requirements, contract Plant Inspectors are used. Also, certain specialist technical inspection services may be employed (particularly in the field of non–destructive testing, to assess the condition of equipment).

The work of all these non–staff inspection services must be coordinated by the static equipment Inspection Authority who shall have the final responsibility for evaluating the results of the data collected, advising management of the condition of the equipment and ensuring that applicable legislation is observed.

Management Delegation of Authority

Management of each plant shall assign the responsibility, and delegate the authority, for the correct application of this Practice to those persons or departments most appropriate and with the necessary technical abilities and qualifications. This delegation shall be in writing.

Organizational Structure

Management of each plant is responsible for ensuring that the static equipment Inspection Authority at the plant is given terms of reference defining the activities for which it is responsible.

The static equipment Inspection Authority shall have direct access to management for those occasions when it is not possible to reach an agreement acceptable to all the functional groups, or for those occasions when the static equipment Inspection Authority deems it necessary to acquaint management directly with information of considerable importance affecting the safety of personnel or equipment.

Basic Responsibilities of the Static Equipment Inspection Authority

The basic responsibilities of an static equipment Inspection Authority shall be:

To carry out inspection of all equipment in accordance with the requirements of this Practice and applicable statutory legislation.
To assign appropriate inspection Grades to equipment as necessary.
To maintain, or have maintained, a register of all equipment, together with detailed and comprehensive records of each item.
To ensure that adequate notice is given when items of equipment are due for inspection, or become overdue.
To advise management whenever the inspection intervals of any item of equipment are reduced or if abnormal conditions of corrosion, erosion or other form of deterioration are detected.
To advise on limiting conditions of pressure or temperature or other conditions of service to which items of equipment may be subjected.
To forecast likely repairs or renewals.
To verify that repairs, modification or renewals to equipment are carried out to the specified design.

To have trained, competent and qualified staff to assist in carrying out the duties which are assigned to him or to obtain specialist advice and assistance as necessary to enable him to discharge his responsibilities in a satisfactory manner.
Inspection Staff
Plant Inspectors employed by the Owner shall be properly trained and qualified per the requirements of EP 15–3–1, and have recognized technical and practical competence to fully satisfy the job requirements.
Where other technical personnel are engaged in assisting or carrying out tests of safety systems, they shall have qualifications and experience appropriate to their duties.
If for economic or other reasons, a Thorough Inspection is carried out by an external inspection agency, management must ensure that its staff are of an equivalent standard of competence to that required of in–house staff, and have clearly defined terms of reference and reporting responsibility.
Specialist Technical Services
From time to time it is necessary to supplement the static equipment Inspection Authority with additional personnel from external agencies or other Owner sites to provide either:
Specialist technical services, or
Additional personnel to cope with periods of peak activity.
These additional personnel may be from companies specializing in non–destructive testing for both on–stream or shutdown examination of equipment. Alternatively, they may be Owner personnel from other plants or Engineering Services.
In either case, the specialist personnel from outside the plant shall only be directly responsible to the static equipment Inspection Authority who will direct their activities, and be responsible for accepting their reports, interpreting them and making recommendations which may arise as a result of them.
External Inspection Agencies
In some states, statutory regulations require that examinations are carried out by an external inspection agency.
Where an external inspection agency is used, the static equipment Inspection Authority will normally be responsible for ensuring:
That management is advised of all requirements for jurisdictional inspection.
That all information relative to the examination is made available to the Owner.
That repairs, renewals, etc., are adequately discussed and agreed by the Owner.
The statutory regulations express only the minimum necessary to satisfy legal requirements, and the documentation supplied by an external inspection agency following their examination of an item is essentially a certificate that the item examined meets the requirements of the jurisdiction. Normally this is insufficient for the Owner’s purposes and, at the discretion of the static equipment Inspection Authority, an Owner’s Plant Inspector may accompany or supplement the work done by the external inspection body to obtain more information on the condition of the item and to predict future repairs and remaining life.

In addition, the static equipment Inspection Authority shall have a responsibility for forecasting likely repairs and renewals. Therefore, maximum use shall be made of on–stream inspection and monitoring techniques.

INSPECTION REPORTS AND RECORDS

General
Each item of equipment shall have had a unique identification number assigned to it (see paragraph 5.1).
The static equipment Inspection Authority shall ensure that adequate and detailed records of all items of equipment requiring inspection are maintained.
Records
The methods by which records are maintained may vary from plant to plant. In all cases, however, each item of equipment must be uniquely identified and fully described.
The records will generally contain the following as appropriate:
Original basic technical data relating to the item, design specification, general arrangement drawings, relevant process data.
Original manufacturing documents, inspection certificates, material quality documents including mill test certificates, pressure vessel code data sheet (where appropriate), rubbings or identification and certification stamps, Manufacturer’s guarantees or certification document, NDT reports, pressure tests, etc.
The construction records issued by the project inspector following delivery to site and prior to being taken into service.
The inspection registration documents and the Inspection Grade assigned to that item by the Plant Inspector.
Copies of all inspection reports issued for that item.
Copies of documents relating to repairs, modifications or renewals made to that item.
Documents relating to calculations made to determine retiring limits, re–assessment of operating conditions or Rerating of the item (see EP 7–3–1).
Documents relating to any abnormal occurrence, including unexpected corrosion, erosion or other defects.
Specialist reports relating to materials, design, process conditions, etc., that will affect the inspection requirements.
Jurisdictional Documents

All such requirements must be strictly observed. All applicable statutory requirements for documentation must be strictly observed.

Reports
The static equipment Inspection Authority shall be responsible for assuring a detailed inspection report is completed as soon as possible, following each inspection.
In addition to fully describing the condition as found, the report shall contain full information on the types of examinations and NDT performed, repairs or renewals which were carried out and also forecast probable repairs or renewals which will be required at the next scheduled inspection.

The report shall finally clearly state the date the next inspection is due, together with any special requirements or facilities, materials or spare parts required at that time, and it shall also state if there is any change in the Inspection Grade and inspection intervals.
Copies of the report shall be issued as appropriate within the plant and a copy also filed in the official item record.
This report will form the basis for decisions on Inspection Grade and inspection intervals.
One report shall fully describe the examinations carried out, the condition of the item examined and detail the components of which the item is composed.

9.0 TABLES

TABLE 1

INSPECTION INTERVALS FOR EQUIPMENT AND INSTALLATIONS

(Excluding storage tanks)

			Maximum interval between Thorough Inspections(1) (months)	Maximum interval between Thorough Inspections(1) (months)	Maximum interval between Thorough Inspections(1) (months)	Maximum interval between Thorough Inspections(1) (months)
No.	Plant or Equipment	Reference	Grade 0	Grade 1	Grade 2	Grade 3
1	Pressure vessels, including heat exchangers	EP 15–4–3	24	48	96	120
2	Spheres and Bullets	EP 15–4–3	48	72	96	120
3	Non–pressure vessels		60	72	96	120
4	Direct Fired Boilers (2)	EP 15–4–5	24	72	96	120
5	Fired heaters	EP 15–4–6	24	48	60	72
6	Pressure–relieving devices	EP 15–4–9	24	48	96(3)	120(3)
7	Stacks and chimneys	EP 15–4–8	24	48	96	120
8	Steel structures		––	––	60	120

NOTES:

Inspection intervals shall run from the date the inspection is completed.
ASME B&PV Code Section 1 Boiler inspection intervals are determined by jurisdictional requirements.
Pressure relieving device test intervals are determined interdependently of equipment that they protect.
Only pressure relieving devices with a satisfactory history and in clean, non–fouling service shall be considered for Grade 2/3 classification. See API 510, Paragraph 4.5, 1995 Supplement.

TABLE 2

INSPECTION INTERVALS FOR ABOVE GROUND STORAGE TANKS(1)

TYPE OF INSPECTION	TYPE OF INSPECTION	TYPE OF INSPECTION	TYPE OF INSPECTION	TYPE OF INSPECTION	TYPE OF INSPECTION
EXTERNAL	EXTERNAL	EXTERNAL	EXTERNAL	EXTERNAL	INTERNAL(6)
In–Service Survey	Roof Survey(2)	Floating Roof Seal(3)	Visual(4)	UT Shell Thickness
				Measurements
				(5)
Monthly	Annually	Annually/ 5 Years	5 Years	5/15 Years	10/20 Years

NOTES:

The intervals in this table, which includes API 653 inspection interval requirements for above ground storage tanks, shall apply unless they conflict with local jurisdictional requirements which will then govern.
May be performed by a designated Owner’s employee other than the inspector who is knowledgeable in tank operations and has received instruction on the areas of concern. Some items should be checked monthly from the ladder. Others should be checked annually during a walk around on the roof (See EP 15–4–4).
Federal EPA requirements for seal gap measurements are annual for secondary seals, once every 5 years for primary seals. State or local jurisdictional requirements may be otherwise.
Formal inspection performed by an API 653 Authorized Inspector.
For new tanks or for tanks with unknown corrosion rates, the interval is 5 years. When the corrosion rate is known, the interval shall be:

Remaining Corrosion Allowance (in.)  0.25 Corrosion Rate (inches/year)

or 15 years, whichever is less

When floor corrosion rate is known from the tank in question or from other tanks in similar service, the maximum interval between internal inspections shall be such that the minimum floor plate thickness at the next inspection shall be no less than:

0.10 inches for tanks with no means of leak detection and containment of a floor leak,
0.05 inches for tanks with method of leak detection and containment of floor leak, or
0.05 inches for tanks with internal reinforced floor linings greater than 0.05 inch thick in accordance with API RP 652.

The Maximum interval shall not exceed 20 years. When the floor plate corrosion rate is unknown, and similar service experience is not available to determine it, the floor plate thickness shall be measured within the next 10 years of tank operation in order to establish a corrosion rate for determining future inspection intervals.

See API 653 P2.4.7 for detail methods for calculating the minimum floor plate thickness.

TABLE 3 SAMPLE LIMITS

Number of Items in Group	2 to 4	5 to 8	9 to 12	12 to 40	Over 40
Minimum number of items in sample	1	2	3	4	10%

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