Cryogenic equipment servicing is often treated as a single line on a laboratory budget, as though one engineer visit covers every obligation a facility has. It does not. A service visit, a calibration, and a statutory examination are three different activities with three different purposes, and confusing them is one of the more common gaps we see when taking on a new site.

What a service visit should actually cover

A proper visit on a vacuum insulated storage vessel should include a physical inspection of the outer shell, neck tube and lid seating, a check of the lid and any autofill fittings, verification that the level and temperature monitoring reads correctly against an independent reference, inspection of hoses, phase separators and transfer lines, confirmation that alarm outputs actually trigger the alarm rather than simply lighting a panel, and a recorded static evaporation check where the vessel type allows one.

For controlled rate freezers the visit covers chamber integrity, thermocouple condition, nitrogen solenoid and injection behaviour, and a verification run against a reference probe. Calibration is a separate documented activity and should be recorded as such, not folded into the service report.

Where the statutory examination sits

The written scheme of examination required under the Pressure Systems Safety Regulations 2000 is not a service. It is a separate statutory duty applying to pressure systems within scope, carried out to a scheme drawn up by a competent person. HSE guidance INDG178 sets out the duty holder’s responsibilities in plain terms. A service engineer attending to check performance does not discharge that duty, and a competent person examining to the written scheme does not service the equipment. A laboratory needs both, and the paperwork should show both.

The first thing a service visit cannot tell you

A visit cannot confirm the long term condition of the vacuum. Vacuum degradation in a static vessel is gradual, and a single day’s observation sits inside normal variation. What identifies it is trend data: the same vessel, monitored the same way, over weeks. A vessel losing vacuum will show a rising consumption trend long before it shows anything an engineer can see on the day. This is why we ask sites to log nitrogen consumption per vessel rather than per site.

The second thing a service visit cannot tell you

It cannot tell you how the equipment behaves when it is being used. Many real world problems in sample storage are not equipment failures at all. They are lid open time, overfilled racks holding the lid proud of its seat, canes stored above the liquid line, and monitoring alarms silenced because they nuisance trip during routine access. None of this is visible during a scheduled visit on a quiet afternoon. It is found by reviewing consumption records and alarm logs alongside the service report.

A reasonable servicing pattern

For most IVF, blood banking and research sites the pattern that works is an annual service visit on storage vessels, calibration on controlled rate freezers at the interval stated by the manufacturer, the statutory examination on its own separate schedule under the written scheme, and continuous in house monitoring of level, temperature and consumption between visits. The visit validates the equipment. The monitoring validates the storage.

Talk to us about servicing

Cryolab has supplied and serviced cryogenic equipment since 2000 and works with IVF clinics, hospitals, blood and tissue banks and research facilities in the UK and internationally. If you want a view on whether your current servicing arrangement leaves a gap, get in touch.