DRY & WET RISERS MAINTENANCE

 

WHAT ARE DRY AND WET RISERS SYSTEMS USED FOR?

 

Dry/ wet risers are intended for the use of the First Service to provide a readily available means of delivering considerable quantities of water to extinguish or to prevent the spread of fire. If your fire risk assessment concludes that you may need the intervention of the Fire Service to fight fire, you must ensure that your riser systems or hydrants are working properly.

 

Before installation of dry or wet rising mains, the local Authority and Fire Officer must be consulted to ascertain the exact requirements.

 

WHAT IS THE DIFFERENCE BETWEEN DRY AND WET RISERS?

 

(Dry/wet risers are often called Rising Mains) Dry riser: system of valves and pipe work which enables the Fire Service to pump water on to upper floors of a building.

 

Wet risers: system of valves and pipe work which are kept permanently charges with water.

 

WHERE DO WE FIND DRY/WET RISERS?

 

Dry risers will be found:

 

• In buildings over 18 meters above ground level

 

• In low level buildings where there are excessive distance from entrances (60m)

 

Wet risers will be found in buildings over 60 meters above ground level

 

THE MAINTENANCE PROCESS DRY RISER ANNUAL PRESSURE TEST SERVICE

 

• Carry out a visual inspection service from roof to ground floor of the entire system

 

• Test the riser with water and pressurise 10 bars measured at the inlet for a period not less that 15 minutes

 

• Whilst test is in progress check entire system for any obvious leakage

 

• No appreciable loss in pressure (0.5 bar) shall be seen whilst the test is in progress or test shall be failed

 

• Drain dry risers completely WET RISER FLOW TEST SERVICE

 

• Carry out a visual inspection service

 

• Carry out flow test in pump room if built in Flow test arrangement exists

 

• Carry out slow test of roof hydrant if conditions allow • Check pressure of system using installation built in pressure gauge arrangement

 

WHY DO DRY/WET RISERS NEED TO BE SERVICED?

 

• Risers are prone to neglect and vandalism

 

• Severe penalties should be rising main fail to work for the Fire Service

 

• Leaking from wet riser could cause substantial damage BS 5306 PART 1 1976 RECOMENDS FOR DRY RISERS:

 

• A visual inspection every six months

 

• An annual pressure test BS 5306 PART 1 1976 RECOMMENDS FOR WET RISERSs:

 

• 2 visual inspection services per year • 2 electric pump inspection service per year

 

• 1 flow test per year (if applicable)