hydraulic system

[marchirom]

Good morning to all, I don't know if I'm in the right section, but I'm looking for a clarification on the scheme of a system that controls pistons. I have no specific knowledge and some components are unknown therefore I ask for help to those who are more experienced in the field.
This is the tensioner of one of the two pulleys of a chairlift, which keeps the pressure within two values. the multitude of components, however, deceives me on the operation.
Can anyone help me?
roberto

 

[TECNOMODEL]

What's the question?
do you want to know what are the 2 components marked in red?

 

[marchirom]

In principle I can understand the operation, but of component 19 I do not understand the purpose, on the net I found similar symbols that speak of logical valves but nothing more. I also don't understand the two non-return valves on the pipe that leads to the cylinder, which have pipes that go into the drain, and which I think I understand are electrocontrolled. Why then are 2 in series?
grit a thousand.

 

[MBT]

Is there a distinct? How is the 19th described?

 

[marchirom]

Unfortunately there is no distinct, the only document I have in my hand is the scheme.

 

[numero1]

I apologize for any errors...... but in my opinion the non-returns you speak of are 2 not piloted return (electronics controlled).
where the opening and/or closing can be suppressed by the driver; In this case I would say the opening.
perhaps at a certain pressure; Probably 2 in series for a security issue.
I don't think of anything at the moment.
Hi.

 

[numero1]

In principle I can understand the operation, but of component 19 I do not understand the purpose, on the net I found similar symbols that speak of logical valves but nothing more.

in fact they seem to be logical valves.........https://books.google.it/books?id=rx...irdai#v=onepage&q=simbolo valvola logica&fse=

 

[marchirom]

hi, by force of searching on the internet I found that the two "not return" are called lock valves, they serve to keep the cylinder loaded for a long time. However, it is not clear if when the pilot opens the valve in the opposite direction of the cylinder's active chamber load, the fluid goes into the tank through the piping or through the circuit. In the first case there would be no limitation in the return speed of the piston.

 

[numero1]

bye, by force of searching on the internet I found that the two "not return" are called lock valves, they serve to maintain I load the cylinder for a long time.

that means the fat part....... :
Does it mean that the cylinder on oil is "supported" and for a long time what it means?
to me have always advised not to do so, for a long time I mean.
If the cylinder has to stay still for a few seconds it's okay, otherwise you use a mechanical block, like a pin locking, a hook, a wolf tooth, a..............
at least I knew so; even if maybe now I can explain why they are 2 valves online one behind the other.

 

[marchirom]

hi number1, I meant that the piston remains in the same position for a long time, about ten hours.
As for the two standard lock valves, I found that they are normally open and block only in case they are electrically driven.

 

[numero1]

10 hours... They put two in line for security then.

I wouldn't do it like that, because at the time they told me it was crazy to do it like this!
Perhaps now there are pistons and valves, ultra-mega-super-galactic, which one can attack for 10 hours all the weight you want.
because the cylinder will hold a weight I imagine......

But I don't know anything.