| Railway Preservation News https://rypn.org/forums/ |
|
| EMC/EMD Pilot Valve Question https://rypn.org/forums/viewtopic.php?f=1&t=47404 |
Page 1 of 1 |
| Author: | Dwalthaus [ Wed May 31, 2023 7:29 am ] |
| Post subject: | EMC/EMD Pilot Valve Question |
In prewar 567 powered locomotives, they used one of the original style pilot valves that controlled the vane type load regulator. In our case, it’s in a 1939 SW1 SP1006. It’s paired to a Electro-pneumatic Governor. The pilot valve has a plunger whose position is inside a ported barrel. The position of the plunger determines what direction and the rate that the vane motor in the load regulator moves. The parts book shows springs, one on each end of the ported barrel, inside the pilot valve. The Maintenance Instruction says that when the inside plunger ports oil through the barrel, that the barrel also moves against the springs. Somewhat of a very complicated compensation design. However, after disassembling a spare pilot valve, we found that the springs were not there. Instead there were perfectly machined spacers that are designed to keep the ported barrel from moving. Only the inside plunger moves. It’s obvious that someone at some time decided that the extra complexity of having a moving barrel plus the plunger was too fraught with problems and decided to eliminate the barrel movement. A search of MI’s and Tech Bulletins didn’t turn up any information regarding this modification. Preston Cook, or anyone else have any insight into the obscure topic? Dave Althaus Diesel Service SCRM |
|
| Page 1 of 1 | All times are UTC - 5 hours [ DST ] |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|