Hello Jim, I am following all of your videos and they are just awesome. I just got confuse at 11:27 minutes when you said that due to imbalance main PRV will open. What I didn't understand here is that main PRV is set at 800 PSI and remote PRV opens at 600 PSI, how it will open main PRV even though system pressure is 600 PSI?
Realize the vent port is "behind" the balanced piston. If something behind consistently gives up at 600psi rather than 800psi the main relief valve will open early. I do a demonstration for my students by having one of them push my hand. I give a token amount of resistance and then I suddenly yield. Depending on my degree of affection for that student I'll either guide their fall towards a clear path or head first into a garbage can. Always an entertaining demonstration.
Thank you for replying back, Jim. Now, I have got one more question. When you said that "If something behind consistently gives up at 600psi rather than 800psi the main relief valve will open early". What is that action or force that will open main PRV at 600 PSI? I am having hard time to visualize that phenomenon. What I understand is that if pilot sprig of PRV is set at 800 PSI, even if the constant knocking of 600 PSI imbalance should not disturb it.
Maybe check out the "Pilot Operated Pressure Relief Valves" lecture at: th-cam.com/video/_mT4q3yW1uU/w-d-xo.html Hopefully this will clarify how the pilot chamber works.
what means vented to atmosphere counterbalance valve? can I use it on the cylinder what operates throught proportional valve with open throttled center? my spring set on the valve shall be 390 bar and only vented counterbalance valves available with these springs settings.
Check out the hydraulic schematics lecture at: th-cam.com/video/NsgShyrcvqA/w-d-xo.html Hydraulic power unit (HPU) at end. Internal drain - outlet port of valve at low tank pressure so drain is internally routed to that same outlet port. External drain - outlet port of valve NOT at low tank pressure so drain is another external port that must be routed to tank
Schematically an external pilot is a dashed line sensing pressure "somewhere else" in the system. Physically a valve with an external pilot will have an additional pilot fitting that needs to be attached to "somewhere else".
great example at 15:36 thanks Jim
great work keep it up
Thank you for this
Great Video!
Good video. Please also explain hydraulic fittings , hose end fittings.
Hello Jim,
I am following all of your videos and they are just awesome.
I just got confuse at 11:27 minutes when you said that due to imbalance main PRV will open. What I didn't understand here is that main PRV is set at 800 PSI and remote PRV opens at 600 PSI, how it will open main PRV even though system pressure is 600 PSI?
Realize the vent port is "behind" the balanced piston. If something behind consistently gives up at 600psi rather than 800psi the main relief valve will open early. I do a demonstration for my students by having one of them push my hand. I give a token amount of resistance and then I suddenly yield. Depending on my degree of affection for that student I'll either guide their fall towards a clear path or head first into a garbage can. Always an entertaining demonstration.
Thank you for replying back, Jim. Now, I have got one more question. When you said that "If something behind consistently gives up at 600psi rather than 800psi the main relief valve will open early". What is that action or force that will open main PRV at 600 PSI? I am having hard time to visualize that phenomenon. What I understand is that if pilot sprig of PRV is set at 800 PSI, even if the constant knocking of 600 PSI imbalance should not disturb it.
Maybe check out the "Pilot Operated Pressure Relief Valves" lecture at:
th-cam.com/video/_mT4q3yW1uU/w-d-xo.html
Hopefully this will clarify how the pilot chamber works.
Thank you, Jim. I will again go through it. The videos are really informative.
Hey Jim great video, but still waiting for your video on reservoir.
Thanks
Here's the lecture on hydraulic power units and reservoirs:
th-cam.com/video/tSc6JfwofIo/w-d-xo.html
what means vented to atmosphere counterbalance valve? can I use it on the cylinder what operates throught proportional valve with open throttled center? my spring set on the valve shall be 390 bar and only vented counterbalance valves available with these springs settings.
Sir,plz explain what is the difference between internal and external drain ?.how to identify seeing hydraulic power pack?
Check out the hydraulic schematics lecture at: th-cam.com/video/NsgShyrcvqA/w-d-xo.html Hydraulic power unit (HPU) at end. Internal drain - outlet port of valve at low tank pressure so drain is internally routed to that same outlet port. External drain - outlet port of valve NOT at low tank pressure so drain is another external port that must be routed to tank
Thanks sir for answering.sir, one more question. How to identify internal and external pilot in hydraulic system ?
Schematically an external pilot is a dashed line sensing pressure "somewhere else" in the system. Physically a valve with an external pilot will have an additional pilot fitting that needs to be attached to "somewhere else".
Terjemahin dong bro 😭