In buildings taller than about 18 metres, or where the fire appliance cannot get close, a dry rising main gives firefighters a pipe already in the building. They connect at the inlet at ground level, pump water up the main and connect hose at the landing valve on the fire floor. It only works if every part is intact.
Six-monthly visual inspection
Every inlet and landing valve cabinet is opened and checked: the door and glazing, padlock and strap, the cap and chain on each outlet, the valve handwheel and spindle, the blank caps, the drain valve, the signage and the pipework where visible. Vandalism, theft of brass fittings and missing caps are the commonest findings.
Annual wet test
The main is filled from a test pump and pressurised to 12 bar for 15 minutes. Every landing valve is checked for leaks and free operation, the inlet breeching non-return valves are checked, and the pressure is monitored for any drop. After the test the main is drained fully and the drain valve closed and secured. A certificate is issued with the result for each outlet.
Why blocks fail
- Missing or damaged outlet caps, so the main cannot be pressurised.
- Seized landing valves that have not been exercised.
- Leaking joints from corrosion or impact damage.
- Inlet cabinets blocked by bins, parking or landscaping so an appliance cannot reach them.