How often should pressure vessels be inspected?
Statutory Inspection periods can be tricky to understand especially when it comes to pressure vessels, it might seem like every vessel has a different period of inspection, and that’s because a lot of them do.
One thing that we do here are Rapallo is to assist our clients to optimize their inspection schedule. If you want to do this yourself, you should start with the regulations.
The requirements for all pressure vessels within Western Australia are governed one of two sets of regulations –
For pressure vessels on mine sites:
- 1. The mines safety and inspection regulations 
For pressure vessels on all other sites:
2. Occupational Safety and Health Regulations 
Both these sets of regulations mandate that all-pressure equipment (any equipment covered under AS/NZS 1200) must be inspected in accordance with AS/NZS 3788. It is this document that will outline the inspection periods required for pressure vessels. If you are on a mine site the mining regulations have some additional requirements for pressure vessels you need to be aware of which are covered in this blog post.
As outlined in the regulations discussed above all pressure vessels in Western Australia must be inspected as per the requirements of AS/NZS 3788. AS/NZS 3788 contains specific information as to the nature of the inspections required, based on the vessel type and the hazard level (as defined by AS4343). AS/NZS 3788 Inspection periods for pressure vessels are detailed in table 4.1, vessels are broken down by categories. Using the table is a simple procedure, first you must determine which category your vessel fits into, then you can read the table to see:
- Whether the vessel requires a commissioning inspection
- Whether the vessel will require a first yearly inspection
- The intervals required for external inspection.
- The intervals required for internal inspection.
- Whether in the internal inspection interval could be extended.
Risk based inspection (RBI).
AS/NZS 3788 is a flexible standard, and it does allow for the inspection periods listed in Table 4.1 to be varied through the implementation of ‘Risk Based Inspection’. This methodology determines vessel inspection periods based on the level of risk. Once a vessel has a service history (or a similar vessel in the same location does), inspection intervals can be developed in line with the risks of operation of the vessel. This risk-based methodology should involve a multi-disciplinary team and a detailed risk assessment involving all stakeholders to that the risks are well understood. An RBI approach is generally undertaken to reduce the frequency of inspections and lower inspection costs. A Risk based inspection regime is a worthy goal for any long-term operation with a significant amount of pressure vessels and can have some outstanding cost benefits. However, the methodology needs to be developed with expertise and care.
If you would like to know more about inspection periods for pressure vessels, need to have your vessels inspected, would like assistance with setting up your inspection schedule or want to determine if your vessels are suitable for risk-based inspection, please contact a Rapallo team member using the form below.