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Product category: Pneumatic Valves and Controls
News Release from: Parker Hannifin | Subject: Pneumatic valve control
Edited by the Engineeringtalk Editorial Team on 09 June 2006

Underground upgrade sticks to timetable

Parker has completed a major refurbishment project of pneumatic valve control units used in the door operating mechanisms on carriages running on London's tube network.

Parker has recently completed a major refurbishment project of pneumatic valve control units, used in the door operating mechanisms on the underground carriages running on London's tube network Parker originally supplied the valve island units over ten years ago when the carriages were first built and the units have since operated reliably in what is a particularly aggressive environment, with high levels of contamination, heat and dust

The valve island refurbishment project was carried out by Parker's Systems Department at Cannock, working for Wabtec Rail, which was responsible for the main project to overhaul the complete door operating systems for 700 underground coaches over an 18 month period.

Although the electropneumatic valve islands continued to operate efficiently, it was recognised that as part of the project to refurbish the entire carriages, full overhaul would ensure further years of reliable service.

Parker's Systems Department is part of the company's Integrated Technology Business Unit, which offers unique remanufacturing facilities designed to provide customers with a cost effective alternative to scrapping used but nonetheless functional equipment.

The valve islands consist of spool valves and wide band direct acting solenoid valves, fixed to aluminium manifold blocks, complete with all electrical and pneumatic connections.

The valve islands are mounted underneath seats in each carriage and are used to provide the control signals to the door opening and closing mechanisms over each single or double door set.

In each case, the valves are exposed to widely fluctuating temperatures and humidity, as the carriages move through underground tunnels and overground sections of rail, plus a mixture of air-borne dust and debris that is unique to the underground system; this comprises both normal dirt, which is blown or carried into the underground, and often highly aggressive particulates released by the braking and other operating systems on each train.

As there is only minimal air circulation it is possible for high concentrations of dust to form on the valve units, with the potential to affect seals and moving surfaces.

Parker and Wabtec Rail jointly completed the refurbishment project on time and to budget, scheduling work so that the majority of carriages remained in service at any time.

Wabtec's Fleetcare engineers decommissioned ten coach sets of equipment per week and then delivered them to Parker to complete the necessary work, each drop included special packaging that was designed to be reused when the refurbished components were collected.

In order to achieve the demanding schedule, Parker had to ensure it kept sufficient stocks of parts over the term of the project, with the valve islands going through a carefully controlled process that included cleaning, strip down and parts segregation for re-use, before being re-manufactured as new to agreed standards.

Once the units had gone through this process, the team at Wabtec would recommission the units.

David Patrick, Project Manager for Wabtec says: "It was a steep learning curve for all parties, although we agreed the decommissioning and recommissioning programme, none of us was sure what would be found with each unit until it was stripped down".

"However, it went like clockwork, thanks to the team at Parker being prepared for all eventualities". Request a free brochure from Parker Hannifin ...

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