Barking Sands
Guru
- Joined
- Dec 24, 2019
- Messages
- 981
- Location
- New Port Richey, Fl
- Vessel Name
- M/V Intrigue
- Vessel Make
- 1985 Tung Hwa Senator
I dont know if there are bypass circuits in the various high pressure pump types. I just did a little looking and didnt see anything for protection from the scenario described. In addition if there was such a valve it likely would be prone to occasional failure and I have never heard of that scenario as evidence of its existence.
Of course on common rail there are bypass valve at the rail. but only so that pressure can go to return.
I dont have detailed schematics but on first glance it appears that scenario would likely be bad in various way. Most return lines are made up of copper tube that has a pretty low working pressure. But burst pressure can be substantially higher. My opinion is the pump would be damaged by way of shafts, pins or castings.
We once had an incident where a crew was troubleshooting a hydraulic issue on an aircraft. The pump is driven off the engine accessory drive. For some reason the tech capped off the "case drain", which is simply a drain to collect the seepage from the moving parts of a hydraulic pump. Once pressure equalized it came apart catastrophically. Good thing it was just ground runs.
I dont think engineers accounted for the "no return path" scenario since it should not be an option.
I personally would just do a 3 way valve. left/right/both
Of course on common rail there are bypass valve at the rail. but only so that pressure can go to return.
I dont have detailed schematics but on first glance it appears that scenario would likely be bad in various way. Most return lines are made up of copper tube that has a pretty low working pressure. But burst pressure can be substantially higher. My opinion is the pump would be damaged by way of shafts, pins or castings.
We once had an incident where a crew was troubleshooting a hydraulic issue on an aircraft. The pump is driven off the engine accessory drive. For some reason the tech capped off the "case drain", which is simply a drain to collect the seepage from the moving parts of a hydraulic pump. Once pressure equalized it came apart catastrophically. Good thing it was just ground runs.
I dont think engineers accounted for the "no return path" scenario since it should not be an option.
I personally would just do a 3 way valve. left/right/both