Sydney Water provides water and wastewater services to the Sydney metropolitan, Illawarra and Blue Mountains regions. Its area of operations covers approximately 13,000 square kilometres and comprises water and wastewater treatment facilities, distribution/collection network assets, and stormwater assets.
In July 2020, Sydney Water launched its new infrastructure and delivery model – P4S: Partnering for Success – designed to simplify procurement, optimise value throughout the supply chain, and deliver $4 billion of construction works and services between 2020 and 2030.
Water and wastewater specialists FITT Resources successfully tendered to undertake work in three main areas under this new delivery model: repair and overhaul of submersible pumping units, centrifugal pumping units, and positive displacement pumping units, with work commencing in April 2021.
Daniel Hechter, Engineering Manager at FITT Resources said, “This major contract tender has required us to work in a variety of ways, on different types of pumps and equipment, but the experience, qualifications and capability of our workshop team and technicians has meant that we have been able to consistently complete asset repair and overhaul work as required. Our safety management, and the ability to meet response time requirements when it comes to workshop operations, logistics and inventory supply have also been crucial.”
Pump repair and overhaul using Chesterton® seals and packing
The scope of the contract meant that FITT Resources would work on a range of different types of pumps from various manufacturers, all of which needed repair, maintenance and overhaul in a variety of ways, depending on the age, condition, location and use of the equipment.
“FITT Resources is one of Australia’s Chesterton sealing products distributors, and our years of experience and knowledge with this world-class product means that it will often, if not always, be specified during repair and upgrade opportunities,” explained Mr Hechter. “It provides a complete system for industrial sealing and pumps reclamation, and there are a number of key features and products that make Chesterton seals and packing ideal for use in the water and wastewater industries. Also, we were conscious that there would be a need to innovate and adapt at times, and the variety of Chesterton products which we have access to; made this easier for us to do.”
There were three main elements of the Chesterton product range that FITT Resources utilised as a part of the P4S: Partnering for Success project.
Chesterton 2211 DualPac Program
Two tunnel pumps that had been in service since their last overhaul in 2015 started having excess gland leakage, as a result of shaft wear and packing degradation.
As part of the ‘stop-gap’ solution, they were re-packed with Chesterton DualPac 2211 1” section, with a bull ring at the bottom and sealing rings on top. This upgrade of the packing has been very successful in terms of the ongoing gland operation.
“Chesterton DualPac 2211 gives you a number of benefits in water and wastewater applications,” explained Mr Hechter, “because it’s made up of both aramid and PTFE. This means you can use it for both ends and sealing rings, and you get superior sealing and low friction, combined with high strength and resilience.”
Chesterton 442 Split Mechanical Seal Program
FITT Resources was also tasked with the upgrade and maintenance of existing raw sewage pumps using Chesterton 442 Split Mechanical Seals. These pumps had originally been fitted with packing, and then later cartridge seals, but the decision was made to replace these with split mechanical seals.
Split seals offer the best sealing solutions in sewage applications because they enable on-site, in-place seal maintenance and replacement, without the need to remove large and expensive equipment from the site (which can lead to downtime and add to costs). The seal set-up utilises API Plan 11 or 13, with close clearance or EnviroSeal SpiralTrac™ gland bushes.
Other benefits derived from using Chesterton 442 mechanical split seals include a spring lifter and spring carrier that provide protection and security for seal faces during installation, less heat generation at extreme pressures due to the balanced seal design, and a compact gland design that means it can fit more equipment without the need for any modification.
Mr Hechter added, “Split seals are a good alternative to packing, as some site HSE requirements prohibit and prevent adjusting packing with the pump running, plus you can change the seal with no disassembly. Split seals can also withstand a larger degree of runout than standard cartridge seals, and there is no leaking of potentially hazardous materials, especially important in sewage applications.”
Chesterton ARC Industrial Coatings
All sewage units were rebuilt and reclaimed using a Chesterton ARC industrial coating, which was chosen to ensure that reclaimed casings and impellers are in the best possible condition to provide prolonged operational life in harsh pumping environments. Chesterton ARC coatings also offer protection against both erosion and corrosion attacks, making it an ideal solution for use with potable water and sewage pumps.
The use of Chesterton ARC industrial coatings also leads to an increase in efficiency (by as much as 6% in some cases) and extends equipment life and reduces downtime.
Mr Hechter explained, “Chesterton ARC coatings can be used to treat pump casings and impellers but have plenty of other uses too. They prevent against corrosion in tanks and hoppers, heat exchangers, and silos, for instance.”
FITT Resources working with utilities across Australia
As well as its recent work with Sydney Water, FITT Resources partners with water authorities and government utilities across Australia and has representation across the country.
The partnership between FITT Resources and Chesterton continues to be an important and fruitful one, with both companies constantly looking for ways to improve and innovate in order to increase plant operating life and reduce the cost of ownership.