Need to drop pressure

[bones1]

I have a 2500 psi pump that I need to drop pressure to about 500 lbs.What type of valve would I use to do this.Flow control, regulator or some kind of restrictor.I will be putting a gauge on the pump to check the output pressure.Thanks in advance.

 

[Wayne County Hose]

Your pump is rated for 2500 psi, but the actual psi will be determined by the amount of resistance between the pump and the tank, thru the pressure side of course.

You can look here- Baileynet.com: Main Page. Check page 57. You will need to pay attention to gpm. I'm sure many other places have relief valves as well.

Just wondering, why 500 psi?

 

[dynasim]

I think that you need a relief valve tee'ed into the system(or to change the set pressure of the relief valve on the tractor).

Chris

Edit: I misread your post. I thought you wanted to drop the pressure 500 psi, not to 500 psi. I would suggest installing the pressure relief on the cyclinder itself. The plumbing is easy, and the valves cheap.

 

[bones1]

Man you're quick Andy.If you remember this post http://www.tractorbynet.com/forums/hydraulics/110654-cylinder-id.html
I have been told by local (experts) that these are low pressure cylinders.If I hook up directly to the "low pressure " cylinders will they be getting 2500psi or only under a heavy load?.I just figured(probably wrong) that giving them a steady 500 or so psi would be better.I also am having trouble finding fittings that will fit the cylinders so I can even test them.The ones on the cylinders are brass and look to be 1/8 pipe where they screw into the cyl body but all the 1/8 pipe I have and bought will not thread in...just a little too big by a hair.Metric.British?????.

 

[Wayne County Hose]

Ahhh yes. Please excuse me. I have 2 brain cells left and some days, they refuse to speak to each other. Today, well, you know.

Yes, you are better off with a pressure relief. If you extend or retract the cylinders all the way, they will draw max. psi until old faithful erupts all over your trailer. You may be able to adjust pressure relief on the pump unit. I'll go back and see if it lists what you are using.

Can you measure the fittings that came out of the cylinder? I need diameter, just like measuring a bolt, and threads per inch and I can tell you what you have. Oh, and if the thread is tapered like pipe thread or parallel like on a bolt.

 

[Wayne County Hose]

Go here- Eaton Product Literature Library > Fluid Conveyance > Weatherhead
Then go to "How to identify fluid ports and connectors." Print that out and guard it with your life. This is the same info hose and fitting distributors use to identify fittings. But, measure them up and I'll tell you what you have.

British pipe would screw in there, would just mess up the threads if you went too far. Metric port has a bonded seal (o-ring with a small metal washer). I'm thinking pipe thread or inverted flare.

 

[AndyinIowa]

If this is a gear pump, you need a relief valve that is rated for the full flow of the pump.

If you need to operate SOME functions at 2500psi, and others at 500psi, you'll need a pressure reducing valve for the low pressure circuit.



AndyinIowa

 

[bones1]

Hi Andy's.Here is a link to the pump.
Washburn Company & hayspear.com JSB Barnes 12 volt Hydraulic pickup hay bale spear pump Andy #1 ,I'll go measure the fittings, I've got thread gauges somewhere around here.

 

[bones1]

Measurements
1. Fitting that came with cyl reads OD .396 at widest dimension of thread.
Thread gauge reads 28 @.0464
2. All other 1/8 pipe I gave reads OD.406 at the widest point.
Thread gauge reads 27 @.0481

 

[Wayne County Hose]

Looks like you have BSPT, British stantard tapered pipe. That's if there is no bonded seal. If it does have a bonded seal, it's BSPP, British standard parallel pipe. British pipe is very very close to national pipe. british pipe is usually 1 thread per inch finer and the threads are cut on a different angle, I think 55 degrees and npt is 60 degrees, one or the other.

I would install a port adaptor out to JIC for ease of plumbing. Try a good local shop or one of the online places. I don't believe I just said that.

 

[Wayne County Hose]

I went to the link for your hydraulic unit. Now somebody help me out here if you know more than I do, it's been a little while since I had one of these units apart. Look in the larger picture of the unit. You see a large dark Hex looking thing coming out of the valve body, between the motor and the tank. I think that's the pressure relief adjustment. Remove the cap and unscrew the thingy a couple turns and measure max pressure. In is more pressure, out is less. Oh, put the cap back on before you energize. I hate hydraulic oil showers and I'm sure you do too. Good luck, Andy.

 

[Mith]

I believe there is a difference in thread between British metric thread fittings and BSP fittings. Most likely you have BSP though.

 

[Wayne County Hose]

I believe there is a difference in thread between British metric thread fittings and BSP fittings. Most likely you have BSP though.

I've never heard of a "British" metric thread. It may exist. Any British thread I have seen is not measured in the metric system.

But, you never know. They are discussing metric flat face fittings over in the Chinese tractor section which I have never heard of or seen until I saw that post.

 

[Mith]

I know there is a metric system of hydraulic fittings. I have been avoiding them so I dont know much about them, I assumed they were British, but could be from the east, as I say, not sure, I just stick to BSP for ease of keeping everything the same.

 

[Wayne County Hose]

I actually like BSP, except for the cost. I think it's the most single versatile fitting out there. I found that it can be used anywhere except in place of Code 62 and Cat flange.

 

[Mith]

Making leak free connections on valve bodies in particular can be a pain, but other than that they are hassle free.

BSP adaptors seem to be cheaper here than JIC and NPTF.

 

[bones1]

Thanks for the ID.I was guessing British.I'll find some fittings online and see I can remove the cover on the relief valve.Thanks again.

 

[3RRL]

Steve,
I just bought one of these to reduce pressure to my Mile Marker hydraulic winch. Although it's minimum is 1500psi, you might search for something like this for further reduction of pressure down to your needs?
Surplus Center Item Detail

 

[bones1]

Thanks Rob.I'll take a look at them when I get to that point.Andy, The cylinders were BSP thread as we suspected.Couldn't find any adapters online but the local auto store had 1/8-27 US pipe x1/8-28 British oil pressure gauge adapters made of steel.Worked perfect.I just need to come up to 1/4 pipe from there. Also these fittings have a smaller hole, about 3/16 diameter in them.Should I drill them out larger or maybe use them as my flow/pressure restrictors??Would that work?? Now on to the mock-up.

 

[Wayne County Hose]

Okay bones, I'm going to let you know my secret place for odd ball fittings. It's a company called Tompkins. They have the adaptors you need to go from your BSP to whatever you want. Whatever Weatherhead doesn't make, I go to Tompkins for. Their website is Stockmeup.com.

You need more of a restriction than that to slow your cylinders down. Tompkins has them. They are also just flow restrictors, not pressure reducers. Pressure is reduced by porting fluid back to the tank at a predetermined psi. Flow is reduced by restriction.

One thing you want to be sure of is if you have BSPP or BSPT. Parallel pipe or tapered pipe. I think by looking at your cylinders, you have tapered pipe. Making sure you have the correct one is important.

Tompkins part #'s are, JIC-BSPP is 3800, JIC-BSPT is 3404, all male by male.
Restrictors, JIC-NPT is RST2404, Pipe swivel union is RST1404.
You then have the dash sizes after the part #. Let me know how you do.