Short & to the point! (but correct)
Dry rising mains
Inlets, landing valves, drain valves, door hinges and locking arrangements to the inlet and landing
valve boxes should be inspected every six months. Special attention should be given to all valves, spindles,
glands and washers to ensure that they are in satisfactory condition, so that all equipment is ready for
immediate use.
In addition, it is recommended that wet tests be carried out annually when the main can be checked
for leaks
In practice many (by no means all) places omit the 6 monthly visual inspection or carry it out in house, concentrating on the annual inspection and 'wet test'
The wet test normally entails connecting the inlet to a pump & water supply (usuallly LPP & hydrant or a fire engine), The system is then completely charged with water to a pressure of 10 bar measured at the inlet for a period of at least 15 min. During this period, an inspection of the system is made to check
that no leakage of water is taking place at any of the joints or landing valves.
I did hear once that one company was using inert gas for testing to prevent water damage if a main suffered a catastrophic failure.
