According to ASME BPVC Section IX:
If a welder has a single qualification for a GMAW process (QW-255) where the base material has P-No. 1 and the filler metal has F-Number 6, is he qualified to execute claddings according to a different WPS which is a special process GMAW CRO (QW-255.1) where...
Let's take the last circuit (even though it's missing a few check valves, but please bare with me) with a counterbalance valve as suggested by HPost.
Once the rod touches the workpiece why can't I assume that Pb is 0? The counterbalance valve is fully open and the rod side is connected to tank...
Perhaps you are right. But can you lecture me on the differences between an hydraulic controller and a "simple" PLC? What does an hydraulic controller do that I can't program a PLC to do?
I was thinking that I could control the set pressure of PPR3 with a PLC and said PLC would communicate with...
I am sorry for the late reply.
Thank you all for your insight and suggestions.
Thank you for the information. May I ask you why is that? What would be the disadvantages of having the higher pressure pump closer to the motor? Not that I need the higher pressure pump closer to the motor, I'm just...
If I unload the big pump won't the cylinder head pressure drop off?
That's why I need the check valve on the big pump, right?
I don't understand this suggestion.
If I have a proportional pressure relief valve with a set pressure of say 5 bar, and PR4 has a set pressure of say 3 bar, won't my...
Thank you. Now I understand why you suggest to use a motion control valve which should be constructed with a poppet type seal.
Yes I agree with you.
Given that and taking into account your suggestion I have changed the flow control valve by a counterbalance valve:
This is the suggestion you...
I am afraid my limited vocabulary doesn't allow me to better explain myself, but HPost is right on the money. What we are trying to design is a simple clamping press. This clamping press must apply a certain force which cannot be much lower than the set point (or the pressure vessel will not...
Definitely. But this hydraulic press is just to apply force to a pressure vessel so that it doesn't come flying through the roof of the factory.
Let me show you a picture of a similar machine:
Nevertheless let us put aside my initial comment and agree that me and my team are trying to design a...
HPost:
We haven't yet chosen the pumps to use. We are discussing if we should use variable displacement pumps with a fixed speed electrical motor or a variable drive fixed displacement pumps.
One colleague argues that fixed displacement pumps become jerky at low drive speeds with output pressure...
My team is designing a pressure vessel testing machine. This testing machine can be simplified and assumed to be a 120ton hydraulic press with a vertically mounted hydraulic cylinder.
Our goal is to use an HMI to set the force the cylinder shall apply to the test piece. The force range is from...
