3 min read

Over the past 20years, we’ve seen and developed some interesting yet hazardous buffer tanks for areas such as mining precincts, nuclear energy plants and even Antartica! These sorts of systems require SafeWorks and AS1210 certification when they fall under higher hazard classifications. This is a quick guide on when this applies and what you need to know: 

WHAT HAZARD LEVEL DO OUR BUFFER TANKS GENERALLY COMPLY TO? 

As per the AS4343, “pressure equipment with a pV < 100, 000 MPa.L or pD < 2300 MPa.mm (before multiplying factors are applied) with non-harmful liquid at a temperature above 0°C but not exceeding 65°C is classified as hazard level E”. 

Thankfully, water doesn’t harm anyone. And for chilled, condenser and heating circuits the temperature is between 0-65°C. Hence, we tick both those boxes for a hazard level E rating. 

The pV value (pressure x volume) provides such a large allowance that there’s no need to stress about your typical system falling outside of this parameter. For example, take a 90kL tank with 600kPa. The pV would be 90,000 x 0.6 = 54, 000 which is much less than the 100, 000MPa.L cutoff.  

Long story short – general buffer tanks comply to Hazard level E.  

WHEN DO HIGHER HAZARD LEVELS APPLY?

Knowing when your system falls into a higher hazard level is important. This may occur in a: 

• High glycol percentage system 

• Air/Nitrogen and water combination  

• Excessive size and pressure scenarios – i.e.100k tank with 1000kPa pressure 

• Temperature extremes – temperatures outside the 0-65°C range, such as subzero or high-temperature conditions. 

The team at Masterflow will always help in checking your documents for any of these situations and elevate this to our engineering department. From there, our senior engineers will run some calculations to check what hazard level the tank falls into and we’ll guide you through the following process.  

WHAT’S INVOLVED WHEN THE SYSTEM FALLS INTO A HIGHER HAZARD LEVEL? 

In any of the above situations, SafeWorks registration and AS1210 certification are required. A third-party / independent design verifier must be consulted, who will review the design specifications, validate calculations, check compliance to standards and issue AS1210 certification if all criteria are met.  

Once verified, the item design and physical item need to be registered with SafeWorks. Both the manufacturer and end-user have a part to play in registration. This includes: 

• PD3 (Plant Design Registration): Required for Hazard Levels A, B, C, and D. 

It is the manufacturer’s responsibility to register the PD3. We will look after this and ensure to keep you updated throughout.  

• Plant Item Registration: Required for Hazard Levels A, B, and C. 

It is the end user’s responsibility to register the plant item. This is done via the SafeWorks website. We’ll be happy to provide direction to ensure this is done correctly.  

Although necessary by law, this process does involve a lot of paperwork, which is why Masterflow is here to help! It will add an extra layer of assurance that the tanks will perform safely under potentially hazardous conditions. This currently costs up to $6, 000 ex GST. We understand this isn’t cheap and will ensure this is communicated transparently at the beginning of the exercise.  

WHAT IS THE HAZARD LEVEL CALCULATION? 

To calculate what hazard level a tank falls into, we factor in both design pressure and volume.  

H = p V Fc Ft Fs 

Where: 

• p = Design pressure (MPa) 

• V = Volume (L) 

• Fc = Compressibility factor 

• Ft = Contents factor 

• Fs = Service factor 

WITH ALL THAT SAID… 

Although it’s not a regular occurrence in the HVAC market to calculate hazard levels and register buffer tanks, it’s good to be informed. We’ll be happy to help and guide you with any hazardous systems you’ve got – send your project specs to [email protected] to get the ball rolling!