Updated: Nov 2
H2X has partnered with HTC group so that designers in Victoria and Queensland can request a mains flow and pressure test directly through H2X.
Accurate town main supply pressure ensures the hydraulic consultants’ hydrant design incorporates pumps and/or tanks early in the design phase and minimises the risk of failing the commissioning test.
Hydraulic consultants go to great lengths to calculate the pressure loss of their hydrant systems to size the pipes and ensure there are no unnecessary pumps and/or tanks. The biggest factor in determining if the design is compliant and efficient, after the calculated pressure loss, is the input mains supply pressure. The hydrant design is only as strong as these two pressures combined.
There are two ways to determine the mains supply pressure. The first is to use water utility model data, and the second is to physically measure the available flow and pressure. Each method has benefits and limitations which are summarised below. Hydraulic consultants may choose to obtain both water utility modelling and physical flow and pressure testing to take advantage of the benefits of both methods.
Water Utility Modelling
• Should provide the supply pressure that is available 95% of the time.
• Should allow for predicted reductions in supply pressure due to future demand changes.
• Models are not calibrated to account for pipe internal corrosion which drift.
• Some water utilities provide overly conservative results.
• Does not account for supply restrictions due to closed supply valves or localised accelerated corrosion.
Physical flow and pressure testing
• Measure the actual supply pressure that accounts for closed network valves and the hydraulic condition of the supply pipe.
• Mimics the test used to commission the system at project completion.
• 5-day lead time.
• Only accurate at the time and date the test was conducted. The supply pressure can fluctuate due to background usage and water utility operations.
• Relies on regularly calibrated equipment and the correct test methodology.
Physical flow and pressure testing ensures that the hydraulic consultants’ design efforts are not weakened by overly, or underly, conservative mains supply pressures. At HTC Group our aim is the same as yours, to ensure each hydrant design avoids pumps and tanks if possible, and to ensure the hydrant system passes the commissioning test with no surprises.
Questions? Contact Dan Barwick from HTC Group at Dan@HydrantTesting.com.au