CASE STUDY: Hydrant Mini Line Stop

Hydrant Mini Line Stop (Hydrant Wizard) has been developed by Morrison Utility Services in conjunction with Wask (Crane Group) and Sarco Stopper Ltd to provide a solution to replace or renew underground type 2 fire hydrants and washouts without the need for mains shut off or customer supply interruption.

Until very recently standard practice for hydrant renewals involved shutting off the main supply and draining down the isolated section. Customers had to be warned in advance of intended shut offs and businesses, schools and institutional facilities had to be considered and consulted to establish the most suitable time to carry out the shut off. This often incurred additional costs for "out of hours" operations.

Substantially more reliable, versatile and cost effective than any freezing off technique, Hydrant Mini Line Stop uses a range of specially developed saddles that can be attached to the hydrant riser or the branch of the hydrant tee itself for shallow pipes. A 32mm diameter under pressure drilling is made through the saddle through which a launch tube containing an inflatable bag can then be inserted. Deployment of the bag and inflation with chlorinated water to 2 bar above operating mains pressure isolates the hydrant from the main water pipe, which continues to operate in its normal manner. The hydrant can then be replaced in a totally safe manner.

On average the technique is used between 1000 and 1500 times per year with one leading water company, saving an average of 70 customer supply interruptions per job, or between 70000 and 105000 supply interruptions per year.

Advantages realised from this innovative solution are; -

• Under pressure live working – no customer supply interruptions
• No valving operations or risk assessments required
• No drain down and depressurisation of the local pipe network
• No constraints due to the consideration of shut offs and their effect on stakeholders
• Most jobs can be planned within normal working hours
• No risk of discolouration on recharge of the isolated section of main
• No risk of "knock on" bursts on the local pipe network as shut downs are eliminated
• Significant reduction in customer call centre contacts or complaints of "no water"
• Significant overall cost savings

For more information, please contact us.