What is the primary use of a percolating fire hose?

It is used in firefighting applications where the hose may be exposed to radiant heat or burning embers, such as forestry, wildland, and external industrial firefighting.

What is the required hydrostatic proof pressure for this hose?

The hose must withstand a proof pressure of 2.1 MN/m² (21.4 kgf/cm²) for one minute without leakage, other than the controlled percolation (Clause 6.2).

What is the specified percolation rate?

The rate of percolation must be between 2.5 and 7.5 litres per minute per metre of hose when tested at a pressure of 0.7 MN/m² (7 kgf/cm²) (Clause 6.5).

What standard sizes are specified for this hose?

The standard specifies hoses with nominal bore sizes of 63 mm and 70 mm (Clause 5.1).

IS 8423

: 1994

Specification for the controlled percolating hose for firefighting

CurrentSpecializedSpecificationFire Safety · Fire Fighting

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This Indian Standard lays down the requirements for materials, construction, dimensions, and performance of controlled percolating hoses used for firefighting. These hoses are designed to allow a small, uniform amount of water to seep through the jacket, which protects the hose from damage when used near embers or radiant heat, making it ideal for forestry and wildland firefighting.

Specification for the controlled percolating hose for firefighting

Quick Reference Values

Nominal bore sizes63 mm and 70 mm

Hydrostatic Proof Pressure2.1 MN/m² (21.4 kgf/cm²)

Minimum Bursting Pressure3.5 MN/m² (35.7 kgf/cm²)

Controlled Percolation Rate2.5 to 7.5 litres/min per metre at 0.7 MN/m² pressure

Standard delivery lengths15 m, 22.5 m, or 30 m

Practical Notes

The 'weeping' or 'percolating' of water from the hose jacket is an intentional design feature to protect the hose from heat and fire, not a manufacturing defect.

This type of hose is generally not suitable for internal firefighting in buildings due to the intentional water leakage along its length causing potential water damage.

Ensure that the couplings purchased are compatible with the hose size and type as per IS 902 or IS 5290.