VOKES filters still flying high with Spitfires

Citation

(1999), "VOKES filters still flying high with Spitfires", Aircraft Engineering and Aerospace Technology, Vol. 71 No. 2. https://doi.org/10.1108/aeat.1999.12771baf.011

VOKES filters still flying high with Spitfires

VOKES filters still flying high with Spitfires

KeywordsAircraft, Air filters, BTR Environmental

As good today as they have always been. That's the verdict of The Aerial Museum in Bristol on BTR Environmental's VOKES range of filters which continue to be used for their high efficiency filtration performance in two of the few remaining Spitfire fighter aircraft in existence.

When the Spitfire was first built in 1938, VOKES long life air and hydraulic filters were reportedly a key feature in the aircraft's success, ensuring that both the air into the Merlin engine and the aircraft's hydraulic oil were kept clean and free of contaminants. VOKES filters were especially important in the harsh flying conditions of the Middle East during World War II. They eliminated problems with sand getting into the engines and causing blockages and engine failure. With VOKES filters, Spitfires were able to operate at maximum capacity for longer, requiring less maintenance and repair downtime throughout the course of the war.

John Had, Chief Engineer at The Aerial Museum in Bristol, maintains and flies a number of historic aircraft including Mustangs and two Spitfires, which includes one of only two Mark VIII Spitfires left in operational condition in the world. Confirming that the filters have truly passed the test of time, John Hart still uses VOKES filters today.

"Parts for the Spitfires can be very hard to come by, but because the VOKES product and design was so good, they proved extremely effective from day one. In fact, I have just used a VOKES air filter which has been in the stock room for 52 years ­ it's working like a dream. The company has just supplied us with a new batch of air and hydraulic filters giving me great confidence in many more years smooth flying ahead."

Over 20,000 Spitfires were built and the aircraft remained in service for the Air Ministry from 1938 until June 1957. Today, just a handful fly on in the hands of private owners and with the RAF's Battle of Britain Memorial Flight (Plate 2).

VOKES filtration systems used in the Spitfires incorporate high efficiency, high integrity disposable filter cartridges. This design ensures that all collected contaminants are removed from the filtration system when a new cartridge is fitted, thus avoiding the risk of clean side contamination. These long life custom made cartridges are typically constructed with synthetic felt, natural felt or cellulose media. Other media are available to suit differing applications. They operate up to a maximum temperature of 100°C and give an efficiency down to 1 micron (depending on the media and cartridge construction). VOKES provides a comprehensive range of filter cartridges specially designed for the removal of particulate contaminants and water from oils including fuel and lubricating oil, hydraulic oils (low pressure systems), machine and instrument oils.

Plate 2 One of the few remaining Spitfire fighter aircraft in existence

Backed by over 70 years' experience, VOKES is a brand of BTR Environmental Ltd which provides a single integrated source of system, product and service support for all types of industrial air and liquid filtration. Other BTR Environmental Ltd brands include DCE, NAFCO, REFILCO, Neotechnik and Hoffman. All BTR Environmental Ltd brands are respected leaders in their field, providing equipment, systems and advanced technological solutions in air, gas and liquid filtration, air handling, dust control and collection, centralised vacuuming, fume control, air knife drying, silo venting and waste management across a diverse range of commercial, industrial, process and engineering applications. Details from BTR Environmental Ltd. Tel:+44 (0) 116 269 6161; Fax: +44 (0) 116 269 3028; E-mail: environment@btrinc.com