Pipe Break Q & A

As promised answers to the most common non turf related questions about the recent main line break I have received.

1/ Why did the break occur ? 
After inspection it appears the contractors who installed the main line did not install the thrust blocks as specified. With set speed pumps cavitation, water hammer is a serious issue with correct thrust block installation critical. Variable speed pumps are the most favoured but the system design took into account our set speed pumps.

2/ Why was water off of so long ?
Due to the holiday period and most manufactures and suppliers closed there was difficulty in obtaining the correct fittings, our irrigation supplier did not have parts on hand had to source parts from various areas across WA. The location of the break only 10m from the bore head could not be isolated.

3/ Why didn't we have parts on hand ?
At the time of installation we were advised due to our limited shed storage area we would only need to carry Toro specific spares, IE sprinkler heads, decoders etc, and the smaller pipe size fittings and pipe, we were assured by our irrigation supplier and successful tender for the installation that all other main line fittings would be readily assessable from their store  24/7 and they would keep an extra inventory on hand for our use.

4/ Why didn't we open the isolation valves from the back 9 bore to water the front 9 ?
We were advised due to the nature of the break, ( a crack extending 1m) and location, between 2 isolation valves 2m apart, we risked the pipe twisting at the isolation valve under pressure and extending the crack further down the line which risk increasing the down time of the irrigation system further.
Another minor influencing factor was the need to operate the system manually if we did connect, as the back 9 is manual and struggles as it is, we would have been taking irrigation away from the back to water the front and both sides would not have received enough irrigation through the weather conditions to meet turf needs, surface deterioration would then have been over a larger area as would recovery. By limiting it one side we effectively reduced the area effected.
If the back 9 was automated like the front this would not have been a factor.

5/ What steps are being taken to avoid future problems as this ?
Firstly we will be carrying emergency parts and fittings ourselves and not be reliant on the assurance we received from our supplier.
We are evaluating whether extra isolation valves can be utilised closer to the bore head, bearing in mind isolation valves are already located 10m from the bore to isolate either one of the two mains leading from the bore head.
Talks on a management level will be held with the supplier to address our concerns.

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