This is an alternative part for the Dukes pump that seems to have a high failure rate.
http://www.airweb.faa.gov/Regulatory_an ... %2018002-b
http://www.mooregoodink.com/news/weldon ... na-owners/
Cleveland, Ohio: Adding to their 65-plus years of successful pump designs, Weldon Pump has just announced a new, electric continuous-duty boost/emergency fuel pump created initially for Cessna applications (See accompanying file for particulars).
A direct replacement for the ubiquitous Dukes intermittent-duty pump, this new Weldon 18000 provides reliable boost support to the aircraft’s main mechanical pump. Alternatively, it can be used as a fuel emergency pump.
Metallic internals: Because it is equipped with all-metallic internal pumping components, notably tool steel blades instead of Nyltralon plastic blades, you will always reach the nearest airport in safety should your mechanical pump fail. Metal blades are superior to Nyltralon blades because they don’t fracture or deteriorate with heat and contaminate downstream components. Furthermore, they self-compensate for wear, thus maintaining their priming and flowing properties.
Pumping capacity and amperage draw: During independent tests measuring pumping capacity and amperage draw, Weldon’s new 18000 innovation easily captured the initiative, generating a minimum of 14.5 Inches Hg Vacuum compared with the 5.5 Inches HG Vacuum of the OEM brand. This impressive pumping power ensures the unit is self-priming, aids vapor clearing, and can be mounted above the fuel source without concern. In an amperage draw comparison, the Weldon recorded .81 amps @ 23 psig operating pressure and 50GPH compared to its rival’s 2.3 amps @ 23 psig operating pressure and 45GPH. The advantage of using fewer amps means that more current is available to power other components/avionics. Further, with its improved efficiencies, the 18000 generates less heat, resulting in cooler fuel.
Voltage ratings, shaft, and seals: Available in two voltage ratings, the 18000-A (14 volts) and the 18000-B (28 volts), these new pumps feature a single solid shaft, double shaft seals to prevent leaks, and a square-drive rotor interface. These improvements, particularly the one-piece solid shaft over conventional multiple small diameter pieces, means the pump is less prone to premature failure and the shaft will not fracture from contamination.
Bypass pressure drop: By reducing the pump’s internal restrictions and, therefore, decreasing the pressure drop across the bypass valve, the 18000 bypasses fuel easier. This feature reduces fuel temperatures, minimizes vapor locks, and improves fuel system performance at higher altitudes. The pressure drop across the Weldon bypass was measured at 0.1842 PSI compared with 0.2702 PSI of its rival.
Currently, additional configurations are being tested on various aircraft, and a two-speed model will be announced later in 2009.
For further information contact:
Weldon Pump
640 Golden Oak Parkway,
Oakwood Village, Ohio 44146
Telephone (440) 232-2282 or visit http://www.weldonpumps.com
Ouch).