Hydraulic Restrictor Orifice

[jinman]

I'm creating this thread with a good title for searching because many TBNers have asked about what a restrictor orifice looks like and how it works. I was at my New Holland dealer yesterday and picked up a spare orifice fitting. This one is about 0.030" and is what I use in my TnT setup and my grapple. It gives me the amount of control I need to accurately position my hydraulic cylinders. The other reasons I like it are that it is inexpensive ($4.95), does not take up much room, and has normal NPT threads. The swivel fitting makes it easy to install also.

 

[J_J]

Is the orifice size stamped on the side?

 

[jinman]

Is the orifice size stamped on the side?

JJ, I was surprised to see that it was not. Previous one's I have bought had ".031" stamped on the hex flat, but on this one, it was only on the bin/box on the shelf. Somebody probably decided they could save money (read "make more money") by not stamping the size on the orifice. Actually, if I didn't see the box, I'd be saying this is more like .040" or .050". The hole looks big to me.

 

[J_J]

Someone might have bored it out some. You can make restrict-ors by just boring out a flat washer, maybe brass or SS. I like the needle valves, so I can set the speed, and change it whenever I like.

 

[kennyd]

Thanks Jim...Now we just need the Surplus Center to stock them!

 

[Gizmo2]

Are these made for 1/4 NPT and where can I find them? Believe me I have looked.

 

[kennyd]

Are these made for 1/4 NPT and where can I find them? Believe me I have looked.

I have a link at home from company that has them, But I think you will be better served with the adjustable kind.

 

[Gizmo2]

I have a link at home from company that has them, But I think you will be better served with the adjustable kind.

How come you're not at work?
Big cost difference. I CAN PUSH THE WIFE JUST SO FAR.

 

[kennyd]

How come you're not at work?
Big cost difference. I CAN PUSH THE WIFE JUST SO FAR.

SSSHHHH! I am at work...That's why I said the link is at home:thumbsup:

 

[Gizmo2]

OK thanks. I am at work also (being quiet)

 

[AKKAMAAN]

A common problem with these small orifices, is that they easy "clogg"....

I have used this design with success.....drill the orifice to a larger size, and put a steel wire trough the hole, and bend the ends of the wire...the cross area difference between the hole and the wire, will be the net orifice opening.....and this wire will work it self back and forth to keep the orifice open.....
The picture shows an orifice through a pin screw...

 

[Gizmo2]

Cool

 

[J_J]

Like Kenny said, a needle valve should work fine. They are adjustable from closed to full open, but they are not cheap. Just adjust till you are satisfied.

https://www.surpluscenter.com/item.asp?item=9-5302-25&catname=hydraulic

 

[kennyd]

OK thanks. I am at work also (being quiet)

Search the term "restrictor" at this website. Good people, I have ordered from them before.

Hydraulicstore.com - Call toll-free 877-778-3533 Mon-Fri 7:30-5:00 Sat 7:30-12:30 Central Time ___________

 

[Gizmo2]

Search the term "restrictor" at this website. Good people, I have ordered from them before.

Hydraulicstore.com - Call toll-free 877-778-3533 Mon-Fri 7:30-5:00 Sat 7:30-12:30 Central Time ___________

 

[Gizmo2]

$2.25, Connector steel orifice 1/4" male pipe x 1/4" female NPSM. Thanks KennyD

 

[IceStationZebra]

Two things.

First, there are floating disc orifices like your picture out there. You get the orifice in one direction and near free flow the other. One application is putting two different orifices on either end of a cylinder to account for the different effective areas. Unfortunately I do not have a source.

Second, a quick/dirty/cheap method is to put a female hex pipe plug inside of a fitting that is already in your system. I have had good luck doing this with male JIC fittings, SAE fittings, etc. Remove as little metal as possible when tapping the fitting, but make sure it don't move. Then just drill out what you want. You can also put in a new plug if you got the hole too big.

ISZ

 

[SPYDERLK]

Two things.

First, there are floating disc orifices like your picture out there. You get the orifice in one direction and near free flow the other. One application is putting two different orifices on either end of a cylinder to account for the different effective areas. Unfortunately I do not have a source.

Second, a quick/dirty/cheap method is to put a female hex pipe plug inside of a fitting that is already in your system. I have had good luck doing this with male JIC fittings, SAE fittings, etc. Remove as little metal as possible when tapping the fitting, but make sure it don't move. Then just drill out what you want. You can also put in a new plug if you got the hole too big.

ISZ

I use a stainless steel set screw drilled for the proper size. Drill before installing. I bought a few each in fine thread sizes from McMaster Carr. For extremely lo flow - like to my system pressure gauge directly off the pump I have used a setscrew with no hole and just let it follow the threads thru. I havnt had it clog and its been on for years. I certainly acknowledge the possibility in so small a flow path.
larry

 

[PILOON]

A restrictor is also easy to make if U can't find them locally.

Simply weld a male female fitting closed and then drill a smaller hole to restrict.
If U start off too small simply use the next size drill bit.

My supplier did not stock restrictors so I made one to slow down a snow blower chute rotator. Worked just fine.

 

[ruffdog]

I just bought 2 blank fittings (1/4) from the bobcat dealer for $3.20 each. the #1404-4-4-blank. Here is a site with those fittings:

144 ADAPTERS - MALE SWIVEL WITH ORIFICE | Trausch Dynamics