INDG1783 min read

Written Schemes of Examination: Pressure Systems

HSE guidance on written schemes of examination under the Pressure Systems Safety Regulations 2000. Explains legal duties for owners and users of pressure systems including boilers, compressors, and pressurised vessels.

Get a free compliance checklist for this guidance.

Get the checklist

Official HSE Document

Read the full official guidance on the HSE website.

View INDG178 on HSE.gov.uk

What is this document?

INDG178 explains the requirements for written schemes of examination under the Pressure Systems Safety Regulations 2000 (PSSR). These regulations apply to pressure systems including steam boilers, air compressors, pressure vessels, and associated pipework.

The leaflet helps owners and users understand their legal duties to ensure pressure systems are properly examined and maintained. Failure to comply can result in catastrophic equipment failures causing death and serious injury.

Who needs to read this?

  • Owners of pressure systems including boilers, compressors, and pressure vessels
  • Users of pressure equipment in industrial and commercial settings
  • Facilities managers responsible for building services equipment
  • Engineering managers overseeing pressurised processes
  • Small business owners with air compressors, autoclaves, or steam equipment
  • Landlords with communal heating systems
  • Anyone responsible for maintenance of pressure-containing equipment

Key points covered

The guidance addresses core PSSR requirements:

Written scheme of examination

  • A documented plan for examining pressure systems must be in place before operation
  • The scheme must be drawn up or certified by a competent person
  • It must cover all protective devices as well as the pressure system itself

Safe operating limits

  • Owners and users must establish safe operating limits for each system
  • These limits define the maximum pressure and temperature for safe operation
  • Systems must not be operated beyond these limits

Examination requirements

  • Pressure systems must be examined at intervals specified in the written scheme
  • Examinations must be carried out by a competent person
  • Records of examinations must be kept

Competent person

  • A competent person must have sufficient expertise and independence
  • They certify the written scheme and carry out examinations
  • Insurance companies often provide competent person services

How this applies to you

Identify your pressure systems

Common workplace pressure systems include:

  • Steam boilers and hot water boilers
  • Air compressors and receivers
  • Autoclaves and sterilisers
  • Pressure cookers used commercially
  • Gas storage vessels
  • Process pressure vessels
  • Associated pipework and safety valves

Establish a written scheme

Before operating any pressure system you must:

  • Have a written scheme of examination prepared or certified by a competent person
  • Ensure the scheme covers all relevant parts of the system
  • Include all protective devices such as safety valves

Arrange examinations

  • Schedule examinations according to the written scheme
  • Use a competent person to carry out examinations
  • Act on any defects or recommendations identified
  • Keep records of all examinations for at least two years

Know your safe operating limits

  • Document the maximum safe pressure and temperature for each system
  • Ensure operators understand these limits
  • Have procedures to prevent limits being exceeded

Get professional advice

Most pressure system owners use an inspection body or their insurance company to provide competent person services. This ensures examinations are carried out to the required standard.

Related Safety Clarity content


Source: This page summarises HSE guidance document INDG178. For the full official guidance, visit the HSE website.

Read the Full Document

This page provides a summary to help you understand if INDG178 is relevant to you. For complete guidance, always refer to the official HSE publication.

View on HSE.gov.uk

Explore Related Topics

Get a compliance checklist

Enter your email to receive a tailored checklist based on this guidance.

We respect your privacy. See our privacy policy.

Last reviewed: 27 December 2025