Glossary term

Fluid Category 4

A fluid that represents a significant health hazard because of the concentration of toxic substances, including chemical or radioactive.

Standards & Regulation

ED devices for Fluid Category 3 and the cases where they are no longer sufficient.

Sizing, materials and isolation strategy for protected wholesome supplies.

Reduced pressure zone valves — installation, AIM, annual testing and Fluid Category 4 protection.

Closed heating and chilled-water filling loops, Category 4 protection and RPZ vs break-tank choices.

Need help specifying?

Our technicians can walk the current risk, the required device, and the assembly that satisfies AIM.

Insight

Missing test cocks, inverted relief valves, and isolation that makes annual AIM testing impossible.

Insight

Closed heating and chilled circuits are Category 4. A double check on the filling point is not enough.

Insight

When a mechanical device cannot replace a Type A air gap — and how to dimension the weir.

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