Pipeline strainers can be seen as an “inexpensive insurance policy” as they help to protect piping systems, says liquid filtration manufacturer Flow Clear Filtration.

The company explains that strainers are available in various materials, types and end connections and the options are there to help end-users to ensure the best possible straining device for each application.

Professionals in the manufacturing industry have realised that strainers are important, using strainers to “strain” or filter contaminates in a piping system that could make their way down the pipeline and damage more expensive pieces of machinery and equipment, or end up spoiling the entire manufacturing process.

The company points out that the choice of the straining element, whether it is a basket or a screen, is usually based on the line media, or what will be travelling through the pipeline. A “screen” is usually used in Y-shaped strainers, while “basket” is the term used to refer to a basket type strainer.

Flow Clear explains that, if an adequate strainer is not installed in a pipeline, it could end up stalling and cause damage to manufacturing processes. Without an adequate strainer, expensive equipment will have to be replaced on a frequent basis.

Elsewhere, the company explains that plant managers are confirming the importance of in-line strainers in keeping equipment clean and clear of debris. Strainers are an inexpensive and reliable way of protecting equipment from debris because they are also easy to install, and maintenance is easy.

It says that strainers are installed into pipelines and allow flowing fluids to pass through unobstructed. By cleaning the flowing fluids, in-line strainers help to protect expensive downstream equipment such as spray nozzles, pumps, compressors and even turbines. Straining and filtering of the pipeline flow are accomplished through the use of perforated or mesh-lined straining elements.

Flow Clear has a team of sales professionals that is capable of helping its clients to select the best type of strainer or filter for specific filtration applications. The company’s insights also extend to helping its clients choose the correct size of filter or strainer, and compile the correct specifications for the pipe units.

The company can design and manufacture a custom strainer or filter to perfectly match any application, as well as having a number of existing units available to purchase.

In November, Engineering News reported that Flow Clear Filtration had had exponential growth in market interest in its locally produced liquid filtration solutions, which are more cost effective and accessible than imported options.

The company’s PS range of automatic self-cleaning equipment, GT range of fabricated basket strainers and BIB-style high- capacity filter bags were designed in-house and introduced to the South African market in 2010. Market response was initially slow, as customers were hesitant to use new products; however, with the filters having proven themselves, demand is increasing, owing to the many benefits the products offer over imports.

Flow Clear Filtration owner George Canning notes that, with little growth in the economy and few new industrial projects and developments taking place, many filtration companies are competing for the consumable filtration market, which encompasses maintenance of filtration elements at existing plants. “However, this competition results in a lot of substandard filters being offered to the market. Customers need to be wary of cheaper products claiming to . . . achieve the same results as higher-quality solutions.”

He adds that most local filtration suppliers import their liquid filtration stock by container- load, leading to an oversupply of products such as standard filter housings, filter bags and cartridges. Simultaneously, the delivery time on specialised requirements has lengthened, as containers come in to South Africa less frequently.

The requirements of SANS 347 and the Occupational Health and Safety Act regarding pressure vessels are, moreover, not widely understood by importers and often ignored, Canning points out. “This can often be to the detriment of South African filter manufacturers who do have to comply, as customers sometimes opt to buy cheaper imported filter housings without certification.”

To overcome these challenges, Flow Clear sought to develop robust, simple and effective solutions that are available quicker than imported products, while remaining cost effective and compliant with safety and quality regulations. “Technical support for these products also had to be much better than what was generally available from importers, who often have little experience in or knowledge of the products they are importing,” says Canning.

Automatic Strainer
A traditional manually cleaned strainer requires extensive labour to be monitored and maintained, compared with the PS range of automatic self-cleaning strainers.

The range has applications in all industries where water needs to be cleaned. Canning notes that the range is particularly successful in gland sealing water filtration, nozzle protection cooling water filtration, wastewater reclamation, mine water treatment and mineral processing, as well as in the pulp and paper, petrochemicals, power generation and food manufacturing industries.

The strainer design incorporates a rotating brush that provides effective screen cleaning by mechanically scrubbing the screen during the purging cycle. The screen is made of stainless steel wedge wire, which Canning points out is stronger and more durable than the mesh used in many other strainers. “As the strainers are locally designed, we can also customise them to fit particular customer requirements, unlike imported strainers that are standard and can seldom be modified.”

He notes that small design refinements have been made since the strainer’s introduction, the most notable being the replacement of the sealed ball bearings on the rotation brush shaft with vesconite bushes. The bushes are more resistant to corrosion when submerged and are the same size as the ball bearings, allowing for easy upgrades in strainers that have been installed.

The strainers have been installed at two large paper mills in South Africa, as well as at a gold recovery operation on the East Rand, in Gauteng. Units have been exported to mines in Botswana, Zambia and the Democratic Republic of Congo.

“To date, we are not aware of a unit that has failed in-service; the sale of spares has been very slow, indicating that the PS range is providing a long and trouble-free service life,” concludes Canning.