Hydraulic return line question.

[Wayne County Hose]

I wonder if the quote he got was for a 1" pressure line instead of a 1" suction line.

I think you're right. I'm on vacation in Florida so I don't have access to my price books, but thinking about it I think you're right.

I just read the original question again. Looks like this is not suction line but return line. Probably should be 1 wire hose. You should be able to drop to 3/4" hose with no problem. For 3' of 1" one wire hose with crimped on ends, that's probably not a bad price.

 

[JSharp]

I wonder if the quote he got was for a 1" pressure line instead of a 1" suction line.

That would make sense since 1" suction line is about $4 a foot...

 

[gemini5362]

ok guys this is the reason I asked the question here because it is a golden opportunity for me to learn something. What is the difference between a suction line and a return line. ?

I am sure it was for a 1 inch pressure line. The connectors they were using on it were pretty hefty and expensive. I did not realize that you use different hose for suction and pressure other than the size.

 

[3RRL]

Here is a basic explanation.
A suction line is the line that feeds fluid to the hydraulic pump from the reservoir. Fluid in the reservoir is not under pressure. The pump "sucks" it from the reservoir and pumps it through under pressure to your hydraulic valves and cylinders. And through them back to the reservoir (return to sump or reservoir).
A return line then, is the line that carries that pressurized fluid back to the reservoir. That line, which is under pressure now, comes from a valve. (That fluid returning has been run through the hydraulic pump.) Once the fluid is dumped into the reservoir via the return line, it is not under pressure anymore.

 

[SnowRidge]

Apparently your setup uses the same line for suction and return. Hence, you shouldn't go smaller than the one inch.

 

[gemini5362]

Here is a basic explanation.
A suction line is the line that feeds fluid to the hydraulic pump from the reservoir. Fluid in the reservoir is not under pressure. The pump "sucks" it from the reservoir and pumps it through under pressure to your hydraulic valves and cylinders. And through them back to the reservoir (return to sump or reservoir).
A return line then, is the line that carries that pressurized fluid back to the reservoir. That line, which is under pressure now, comes from a valve. (That fluid returning has been run through the hydraulic pump.) Once the fluid is dumped into the reservoir via the return line, it is not under pressure anymore.

Thank you for that nice simple explanation that makes a lot of sense of the difference. In my useage the other posters that say the return and the suction is the same line is correct. The ram is inside of a larger cylinder. The larger cylinder is used as a storage medium. To fill up the cylinder I ran a hose to the suction side of my pump and poured hyraulic fluid in to the pump while running it and letting the ram extend raising the dump bed. When The bed was raised all the way I took the line loose and then attached the line from the cylinder that is used as a resevoir to the pump side labeled suction. ( I realize that is also the return line) I opened the valve letting the fluid out of the ram and into the storage part of the cylinder. If I understand your explanation and put it with the little bit of hydraulic knowledge I have. A suction line is usually attached to a storage tank which is vented and therefore has no pressure on it. This is going to a storage which is not vented at all. Would the return/suction line still have a small amount of pressure on it from the ram being pushed down by the weight of the dump bed or would the bleeding off of the original pressure to the ram be negated and basically the suction side of the valve be at 0 pressure when the dump is all the way down.

 

[3RRL]

Probably zero, or just a little (atmospheric).
Depends on if draining the storage causes a vacuum or not? It's the air in the storage that compresses or gets like a vacuum. I don't know for sure in your case.

Note that my explanation was basic, because once the fluid passes the last valve and goes right to the sump/reservoir, it is now not under the same pressure as before the valve (since it is dumping to atmosphere). So a true return line can be of lesser PSI rating than a working pressure line.

Note also that suction and return hoses need helix wire to resist collapse due to vacuum or bending....not just any rubber hose. That is because as the line gets hot, sometimes they want to collapse if the pump is sucking real hard, so you need to watch out for that. Maybe go here to see what is available and what fits your usage, like the last 2 hoses shown.
Hydraulic Hoses

 

[gemini5362]

Probably zero, or just a little (atmospheric).
Depends on if draining the storage causes a vacuum or not? It's the air in the storage that compresses or gets like a vacuum. I don't know for sure in your case.

Note that my explanation was basic, because once the fluid passes the last valve and goes right to the sump/reservoir, it is now not under the same pressure as before the valve (since it is dumping to atmosphere). So a true return line can be of lesser PSI rating than a working pressure line.

Note also that suction and return hoses need helix wire to resist collapse due to vacuum or bending....not just any rubber hose. That is because as the line gets hot, sometimes they want to collapse if the pump is sucking real hard, so you need to watch out for that. Maybe go here to see what is available and what fits your usage, like the last 2 hoses shown.
Hydraulic Hoses

I imagine the next to the last one would do it. I am not sure what pressure is on the ram but for the load it lifts probably over 2000 psi. but like you indicated the return side of the valve will be a lot less pressure. I need to just go to one of the local shops that makes hoses and see what they want to charge me. The place that wanted 65.00 is an auto parts store so I am sure they want a fortune compared to what other places get. Thank you for taking the time to answer my questions with easily understandabele answers

 

[Wayne County Hose]

Oh my. Sorry, but I cringe when people tell me they go to an auto store for hydraulic hoses. Funny, nobody comes to me for auto parts.

Probably first thing you will be asked is, "What's this off of?" If there are no distinguishable markings left on the hose to identify it, they may cut it in half to identify it. Therefore, giving you the correct hose for your application. The hose may be $30, or it may be $130. But, you'll get the correct hose.

 

[gemini5362]

Oh my. Sorry, but I cringe when people tell me they go to an auto store for hydraulic hoses. Funny, nobody comes to me for auto parts.

Probably first thing you will be asked is, "What's this off of?" If there are no distinguishable markings left on the hose to identify it, they may cut it in half to identify it. Therefore, giving you the correct hose for your application. The hose may be $30, or it may be $130. But, you'll get the correct hose.

The auto parts store was actually pretty good they had hoses and they had fittings I took the hose in to the auto store and they were going to be able to make it. When I checked the price I stopped them before they started because I believed I could get it made for less. The only reason I went to the auto parts store was because I was at work and went there during lunch it was 7pm and they were the only place that was open that made hoses. If it makes you feel better I am going to go to a place that only makes hoses and not sell any auto parts to have one made.