Maintenance of pipelines can be a tricky business. Sealing and testing operations need to be conducted not only with complete safety and environmental security, but also with considerable speed, to maintain flows of liquids and gases.
One method of stopping and sealing that is attracting increasing interest and application in Australasia involves inflatable pipe stoppers that can be rapidly deployed, easily transported and widely applied in remote, temporary and permanent industrial situations.
The Pronal inflatable pipe stoppers from pneumatic actuation and isolation specialists Air Springs Supply Pty Ltd are used for maintenance, testing and emergency tasks in applications as diverse as oil and gas delivery, industrial and municipal water and waste water, and pollution prevention in mining energy projects. One of the latest inflatable pipe stoppers employed in Australasia (pictured) is a custom-fabricated OFR type, to fit a pipe with an inside diameter of 900mm. Multi-sized stoppers are available in an expanded range spanning pipes from 45-2115mm diameter in stock sizes and up to 3000mm for customised types. Different ranges respond to the needs of particular industries and pressure requirements, with VPE and ORJ types being used for pressures up to one bar and OPV types for pressures up to 3 bar. Higher pressure stopers are also available.
The enormously strong inflatable pipe stoppers are produced by elastomer products specialists Pronal, the company that produced the inflatable bags used to lift sections of the liner Titanic from nearly four kilometres underwater in the Atlantic Ocean. The versatility of the material used and the production method (customized dilatability) means Pronal inflatable stoppers are suitable for all types of pipelines including concrete, cast iron, steel, stainless steel and PVC, he says. ”They are extremely strong and durable in service, being hot vulcanized in a mould and Kevlar reinforced, giving outstanding service life.
”External surfaces are also customised to particular needs, such as exposure to gas or petroleum products or where long term installation is required. “Naturally (as with any rubber-based product) direct or prolonged exposure to petroleum-based products is not recommended, but even so they have strong emergency use applications in such industries, where speed of deployment is vital.
“Inflated at the specified pressure and with a back-pressure of up to 1 bar for standard types (10m water column), each stopper can be used within a range of pipe diameters. For example, a range of just four stoppers is needed to span the 100-1200mm diameter pipe sizes
Inflatable pipe stopper types include:
- Vari plugs 45-1500mm with blank stopper, bypass for watertightness tests; and rod for mini pipes
- Uni-Plug collapsible pipe stoppers from 20-3000mm that compactly fit around obstacles, corners and into previously inaccessible areas of surface, underground and underwater pipelines.
- Pollu-Plug and anti pollution stoppers permanently fitted in stormwater and sewerage lines ready for rapid inflation by remote triggering as soon as an emergency arises. The deflated stopper is designed to allow normal non-polluted effluents or water to pass through the pipe when the stopper is uninflated.
- Mr Agar says the Pronal stopper range, for which Air Springs is exclusive national distributor, is one of the most extensive ranges available nationally and internationally. In addition to standard products, Pronal customised products include low and high pressure resistance models (according to the application). Custom-build models also come in a variety of shapes - cylindrical, egg-shaped, square – and up to 3,000mm diameter. Special models can be manufactured to meet particular specifications.
“They are also highly versatile in uses such as testing air, gas and water pressure, locating leaks, and even allowing the injection of chemicals or dies into a pipeline when facilitating cleaning or locating leaks in designated sections between two stoppers. By using the bypass function within the appropriate stopper, chemicals can be introduced then subsequently either diluted for disposal or purged to tanker or reservoir. It’s very quick and clean.
“It is also very secure. Pronal products are based on more than 40 years of producing specialist pneumatic elastomer designs for demanding applications, including government, military, heavy industrial, emergency service, sub-sea and exploration” said Mr Agar, whose own organisation, Air Springs Supply, also has more than 30 years specialist national experience in applying pneumatic actuation and isolation technologies.
“The big advantages of the technology also include simplicity, portability and re-use. Maintenance staff don’t need huge amounts of gear on-site and the stoppers themselves are easy to transport around plants to remote locations, where they can be used, moved on, and used again and again.”