Pressure reducing valve disintegrated

1
Pressure reducing valve disintegrated
Water delivery/suction line
Damage to PRV Station
Pretoria academic Hospital Before
2
Pretoria Academic Hospital Before
Damage due to the high pressure in the plant room
Pressure vessels
Pressure vessels went through the roof of the
building
3
After the repairs
Pressure reducing valve New
New Pressure Vessels
4
Roof Replaced
Replaced Control panel
5
During the morning of July the 5th 2007 round
about 05h45 we (the workshop) were informed of a
water leak in the scan area on level 5. On our
arrival to this area we discovered that a clamp
on the hot water supply was leaking extensively
which caused a lot of damage in this department.
On further investigation we found that the
rubbers on this clamp kicked out and we decided
to check the main pressure reducing valves which
are located near the reservoir. We found that
there was a leak on the incoming reducing station
and presumed that this leaking (cracked) valve
was the cause of our problem. While the
plumbers, which Impophoma send tried to rectified
abovementioned problems the local works team
repaired the leaking valve on level 2. Spares
could only be purchased on the following day so
we decided to meet with Impophoma the next
morning which were Friday the 6th of July. After
we met on Friday morning two of the local works
group plumbers assisted the plumbers which were
send by Impophoma until they finished later on
that day. Everything was checked and the water
supply of the building was opened by 12 oclock,
before the works team knocked off that afternoon,
the pressure on the incoming p.r.v.s were
checked for the correct working pressure
6
. On Saturday morning 01h30 the foreman on
standby received a call that there was water
flowing on the premises and also down Malherbe
Street. The foreman notified the plumber on call
and on inspection of where the water was coming
from he discovered that something went wrong at
the supply pump station which are located on the
western side of the main building. The buildings
roof and one of the pressure reducing vessels was
lying on the ground in front of the pump station.
The plumber rushed off and closed the main
water-supply and then notified everybody
according to the protocol. After an inspection
was done by our mechanical inspector it seemed
that the water supply from the city council may
have caused pressure serge where the pressure in
the pipe rose to 21 kpa on the incoming side.
With the pressure this high combined with air
(airlock) the diaphragm is easily damaged. The
normal incoming pressure is usually only 16 kpa,
but after a meeting that was held between us and
the appointed contractor provision has been made
for safety valves to prevent this incident from
happening again in future. At this stage the
local works team are also assisting the client
with the supply of water to the building while
the appointed contractor are busy rectifying the
damage caused by the high water pressure. The
damage was repaired and returned to normal with
in a week as some of the equipment was
manufactured and imported Total cost to repair R
497,945.16