Great Britain Dutyholders: Written Scheme of Examination Comparison

Before first use or statutory examination, a Great Britain pressure-system dutyholder should commission a written scheme of examination drawn up or certified as suitable by a competent person.[1][2]

• Required where Regulation 8 applies: the scheme must cover every pressure vessel, all protective devices and any pipeline or pipework sections whose failure could cause danger. It must specify the nature and frequency of examinations and any special preparation measures.[1]
• Not prescribed: PSSR does not set a standard scheme format, and a drawing is not mandatory, although SAFed considers one potentially useful for complex systems.[6]

Determine whether PSSR applies

Under Regulation 8 of the Pressure Systems Safety Regulations 2000, the user of an installed system—or owner of a mobile system—must not operate it, or allow it to be operated, without a written scheme for periodic examination by a competent person where the regulation applies.[2]

As an initial screen, HSE describes a pressure system as one containing, or likely to contain, a relevant fluid above 0.5 bar.[1] This is not the complete legal test: check the full PSSR definitions, exclusions and partial exceptions rather than relying on pressure alone.[1][2][6]

The assessment should consider pressure, fluid type and properties, equipment and pipework suitability, age and condition, operational complexity and control, temperature and the competence of those maintaining, testing and operating the system.[1]

For compressed-air systems, treat the 250 bar-litre threshold carefully. SAFed says that if any vessel in a system exceeds that pressure-volume product, every vessel in the system must be considered for inclusion in the scheme.[6] PressureSafe describes systems above the threshold as likely to require a scheme.[4] Neither source presents it as a universal trigger for every pressure-system type.

Define the equipment covered by the scheme

Once applicability is established, define the system boundary to capture:

• every pressure vessel;
• all protective devices, including safety valves, bursting discs and relevant electronic appliances; and
• pipeline or pipework sections whose failure could create danger.[1]

Prepare a controlled information pack before requesting quotations so each provider works from the same plant scope.

• Plant schedule: list each vessel, protective device and potentially dangerous pipework section. SAFed says the owner or user remains responsible for keeping the schedule correct and current.[6]
• Boundaries and interfaces: define each system and subsystem and cross-reference interconnected pressure systems.[6]
• Fluids and operating conditions: identify relevant and deterioration-causing fluids, start-up and shutdown conditions, cyclic loading and foreseeable excursions.[6]
• Condition and operation: provide available information about equipment and pipework suitability, age, condition, controls and competence arrangements.[1]
• Drawings: include controlled drawings where they clarify a complex installation and keep any drawings used current.[6]

Require the proposed scope and plant schedule to be returned for approval before certification. SAFed places responsibility for the scheme’s scope and plant schedule with the owner or user rather than transferring it entirely to the competent person.[6]

Specify what the competent person must certify

For every covered item, the certified scheme must state the nature and frequency of examination and any special measures needed to prepare the system safely.[1] The scheme must be drawn up, or certified as suitable, by a competent person with the necessary skills, knowledge and experience.[1]

For document control, ask for the following representative SAFed fields:

• scheme reference, issue date and revision details;
• certifying body and competent person;
• system category, dutyholder, location and description; and
• the person who drew up or updated the document.[6]

These fields are not a compulsory layout. SAFed says neither PSSR nor its Approved Code of Practice prescribes a standard WSE format.[6]

Do not impose a universal examination interval or copy one from marketing material. The competent person must set the frequencies in the scheme; SEIS’s published intervals are recognised industry benchmarks from SAFed PSG01, not legal defaults.[1][3] Examination under the scheme assesses suitability for intended use but does not replace routine maintenance.[1]

Set a handover gate before use

Make release to service conditional on receiving and checking:

• the certified written scheme, including each covered asset’s examination nature and frequency;[1]
• instructions for isolation, cleaning, access and other preparation specified for safe examination;[1]
• completed competent-person examination reports where an examination is required;[1] and
• the recorded next-due date for each item subject to periodic examination.[5]

HSE says the written scheme, where applicable, and competent-person inspections must be completed and recorded before pressure equipment is used.[1] Where an initial examination is required, SAFed recommends carrying it out after installation and before first use. It also recommends considering an initial examination for subsequently added equipment, even if the item may later be excluded from routine examination.[6]

CertFlow’s 2026 article recommends retaining the scheme and review history, examination reports and next-due dates, safe-operating-limit and protective-device records, maintenance and modification evidence, defect reports, and confirmation that danger-related repairs were completed before reuse.[5]

As procurement controls, reconcile the plant schedule, certified scheme and examination reports asset by asset before acceptance. Also name the party responsible for future scheduling and require a defined transfer process for reports, due dates and scheme records when the provider relationship ends.

Revisit the scheme after plant changes

Report additions, removals, replacements and extensions to the competent person so the scheme and plant schedule can be updated.[6]

The scheme should identify critical parts requiring referral to and examination by a competent person after substantial repair or modification and before reuse.[6] HSE says a major repair or modification may require the whole system to be re-examined before its return to use, and modifications should be planned and recorded.[1]

For changes to fluid, pressure, temperature, duty cycle or intended use, obtain a competent-person review before relying on the existing scheme. HSE frames examination around suitability for intended use, while SAFed recommends recording relevant fluids, operating conditions, cyclic loads and foreseeable excursions.[1][6] These sources do not establish an automatic statutory examination trigger for every such change.

1. Define the change and affected system boundaries.
2. Update plant information and controlled drawings where used.[6]
3. Obtain the competent person’s decision on scheme scope and any examination required before reuse.[1][6]
4. Retain the revised certification, examination record and release-to-service evidence.[5]

Compare four delivery models

The options divide into outsourced competent-person services, a collaborative training model and compliance-management software. They are not interchangeable.[3][4][5][7]

SEIS Engineering

• Delivery model: SEIS says it prepares or certifies written schemes, examines equipment to the scheme and issues both documents digitally.[3]
• Competent-person role: The service is presented as independent competent-person provision.[3]
• Practical scope or limit: SEIS describes gauge verification, safety-valve lift testing, vessel checks, scheme-directed non-destructive testing and hydraulic testing where necessary. It states that it operates across the UK.[3]

Mandate Systems

• Delivery model: Its quotation form offers scheme creation, examination or a combined service.[7]
• Competent-person role: Mandate describes technically qualified staff supported by an in-house Chartered Engineer.[7]
• Practical scope or limit: It offers support for minor, “immediate” and major systems, although SAFed calls the middle category “Intermediate”. Mandate says hired mobile compressors normally remain the owner’s scheme responsibility unless agreed otherwise.[6][7]

PressureSafe

• Delivery model: PressureSafe trains service-provider engineers and collaborates on dual-branded schemes for minor systems.[4]
• Competent-person role: Its chartered engineer certifies the scheme; creating or signing it is outside the trained engineer’s role.[4]
• Practical scope or limit: Training covers non-destructive examination of specified compressed-air equipment, receivers, safety devices, autoclaves and accumulators. Candidates need at least six months’ pressure-equipment experience, while customers remain responsible for competence on specialist equipment.[4]

CertFlow

• Delivery model: CertFlow is presented as compliance-management software rather than a competent-person commissioning package.[5]
• Competent-person role: Its described role is managing WSE activity, not supplying the competent person.[5]
• Practical scope or limit: The software links schemes to systems, schedules examinations with the appropriate competent person at scheme intervals and retains searchable reports.[5]

Choose a model

These are delivery-model comparisons, not independently verified rankings. SEIS and Mandate describe outsourced scheme preparation and examination services.[3][7] PressureSafe describes a training and collaboration model for defined minor systems.[4] CertFlow describes software for organisations that already have competent-person provision but need scheduling and record control.[5]

Write the selected model into the purchase order, including asset boundaries and exclusions, competent-person identity and competence basis, certification responsibility, examination methods and intervals, preparation duties, deliverables, change control and record portability.

What to confirm with each provider

The cited pages do not publish actual prices or establish independently audited outcomes or service-level guarantees. CertFlow states that it has no minimum term, is a rolling monthly subscription, permits cancellation at any time, answers support within one working day and serves UK inspection firms; service territories for PressureSafe and Mandate are not stated.[3][4][5][7]

• Request an itemised quotation covering scheme preparation, certification, examination, travel, testing and document updates.
• Confirm service territory, attendance times and any subcontracting arrangements.
• Obtain the minimum term, renewal, cancellation and termination provisions in writing.
• Define ownership, format and transfer of schemes, reports, due dates and other records.

This comparison covers Great Britain under HSE guidance and the Pressure Systems Safety Regulations 2000.[1][2] Check Northern Ireland’s legal and regulatory position separately.

References

1. Introduction to pressure equipment – HSE (hse.gov.uk)
2. The Pressure Systems Safety Regulations 2000 (legislation.gov.uk)
3. PSSR: Written Schemes, Examination & Certification Guide (seis.engineering)
4. Written Schemes of Examination (WSE) by PressureSafe (pressuresafe.co.uk)
5. PSSR and the written scheme of examination explained | CertFlow (certflow.co.uk)
6. Guidelines Pressure Systems Guidance for the Competent Person (safed.co.uk)
7. Written Scheme of Examination Documents at Mandate Systems (mandatesystems.com)