Schematics question 4

[Josef10901]

Hello,

Please excuse my ignorance, as I am new to this field. I am wondering what these check valve symbols are supposed to mean on these schematics, specifically when they are facing each other? We have the DLOH-2C valve specifically and I can't figure out how it functions in the first position. Any help and/or reading material would be greatly appreciated. Schematics are shown in the picture linked below,

Thank you,
Josef

 

[Compositepro]

Those are not check valves. They simply indicate the port connection location and indicate that the valve is closed and that there is no connection between the ports. When the valve shifts the two ports are connected.
The drawings used two squares next to each other, representing the valve. Each square shows the internal flow connections of the vlave in each of its two possible positions.

 

[BrianPetersen]

The use of the symbol of a check valve in that application is unusual. The usual representation of a blocked port is a "T" or an inverted "T", and I am pretty sure this is what is actually meant.

 

[Josef10901]

Thanks both of you for the help! That makes sense now.

 

[Bruksarn]

Seat valve, poppet valve, leakage free.

 

[itsmoked]

When un-operated the right block is in position. It is there due to the spring on the right pushing it there. When flow is controlled by the right-side block there is no path thru the valve. Flow is blocked.

In the operated position the solenoid on the the left is energized and over-rides the spring shoving the left block in to the controlling position. In that position the flow runs straight thru the valve from P to T.

There is nothing "check valve" about it.

A check valve can be seen in the DLOH-2C/R symbol. It's the thing at the bottom right; a V with a circle in it.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[hydtools]

It seems unusual that the blocked port conditions are represented by interior check valves. That may be leading to the confusion and question.

Ted

 

[Bruksarn]

https://www.rg-group.com/resources/blog/what-is-a-poppet-valve

 

[zeusfaber]

Bruksarn,

Thanks for the link - I'd not come across that drawing convention before.

- and welcome to Eng-Tips. Hope you'll enjoy it here.

A.

 

[itsmoked]

!! I can barely see those internal check-valves if a super-zoom magnify them. Minor zoomed they look like circles with four points. Thanks for pointing that out hydtools.

Brukarn; Thanks for that educational link!

Keith Cress
kcress -

http://www.flaminsystems.com

 

[hydtools]

Learn something every day.

Ted

 

[Jacc]

There is nothing unusual or wrong with this type of symbols.
As already stated, this symbol means that it is a poppet valve (aka seat valve) and not a spool valve.
A poppet valve is virtually leak free unlike a spool valve which always has some leakage.

Poppet valves are used where a leak free valve is required, for instance holding up a load on a cylinder or in conjunction with an accumulator for emergency power.