Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


hose and fittings question ....

hose and fittings question ....

hose and fittings question ....

So, the last time I bought hydraulic hoses from a local supplier (who has since gone out of business), I simply told him I needed a 36" long hose with 3/8" NPT fittings (for a snow plow) ... I don't think he even asked what pressure rating, just assuming it was under 3000 psi. He didn't ask me how may wire lays or if I wanted "w" type fittings or much of anything.

Anyway .... I was about to order a flex hose and was a bit confused by my chooses.

I need: 36" long, I am running under 3000 psi (max my power unit will put out ... relief set to 2700 psi), SAE (ORB) 08 (1/2")fittings

So, the first item I pick is "hydraulax tough" from Discount Hydraulic Hose. 2 wire, 5000 psi, 3 1/2" bend radius .... $2.50 a ft ... looks great.

Then I keep reading ... R12 "very high pressure hose" ... 4 wire! but it only is rated at 4,000 psi with a 7" bend radius and costing $5 per ft.

And there are obviously other chooses (R16, R17, ...)

So two questions ....

1) as long as the pressure ratings are OK, is does it matter what hose I choose? I would have thought more wire wrap layers is better but yet the one with 4 layers has a lower pressure rating that the one with 2 layers.

2) some say "braided hose fittings" (standard crimp), some say "series W fittings" (bite to wire) and some give me a choose of either. I tried to find an explanation on the web ... I don't see one. I "assume" (but wanted to check with you guys" that the "bit to wire" fittings were better as I am guessing they penetrate the outer layer of rubber and "dig in" to the outer wire wrap layer.

Just want to make sure I order the correct hose.

Thanks ...... Mike

RE: hose and fittings question ....

A lot of what you are reading is puffery.

The bite through fitting may be appropriate for the heavier cover "10X" more abrasion resistant Tough hose.

Mixing fitting brand and hose brand may be risky, especially if the crimping equipment does not correctly crimp the fitting to the hose, bite through or not.

Will the hose shop assure fitting and hose will meet your pressure requirements? Who manufactures the Hydraulax branded hose?

You pays your money and takes your chances.


RE: hose and fittings question ....

Hmmmmm ...

So I take it,what you are telling me is that I should think about using a "name brand" hose?

So is one better than another I see Parker, Eaton, Gates ( I think I had gates on my snow plow ) ....?

Does the same go for fittings? Is a "brand name" fitting better than a "no name" brand? Is there a brand I should think about?

I just made the bad assumption that if they were "rated" for a certain pressure, they would work but maybe this is not the case?

Thanks ..... Mike

RE: hose and fittings question ....

I should have asked also ... are all hydraulic hoses OK to use with synthetic oil?

I was planning on using the Royal Purple "Syndraulic". I did confirm that the oil is compatible with the buna seals in my pump.

Thanks again .... mike

RE: hose and fittings question ....

Sooooooooooo (sorry ... I keep adding to my post) ....

I did more reading and may have found one answer ...


I looked at this page and it has a chart saying only hose 100R7, 100R8 and 100R14 are compatible with synthetic fluids.

Discount Hydraulic Hose does not even sell any of these hoses!

I am confused a bit ( nothing new ) .... the guys at Royal Purple (actual factory not local rep) is telling me their fluid is compatible with petroleum based oil as they recommend it at a replacement for "regular" hydraulic oils.

Then why is there only three hoses that are "rated" for synthetic oil???

Thanks again ..... Mike

RE: hose and fittings question ....

You have to look at the inner tube material for compatibility with your synthetic oil. Or look at the synthetic oil material compatibility list.

Back to fittings. The bite through would be used with non-skive hose and the other crimp fitting would be used with skived hose. Skive=remove the outer cover. Non-skive=do not remove the outer cover.


RE: hose and fittings question ....

Got it!

I was just about to write Royal Purple and ask their advice on hydraulic hose.

It is amazing how something as simple as wanting to use synthetic fluid can affect so many things. As I said in earlier post, I don't "need' to use synthetic fluid, I was just going to as I know it has superior lubricating qualities especially during start-up.

In honesty, I will probably take out the flex line when I am do setting the lift and pump. Right now the lift has some adjustment in it so I can align the lift. The original forklift was designed with a slight tilt (backward) of the mast. I need the lift to travel "straight" up to maintain the clearance between the car and the walls. I need the flex till I get everything set and lock in place.

Thanks again ..... Mike

RE: hose and fittings question ....

Forklifts tilt the mast to put a little slope on the fork roots, forward or back, to ease engagement and to compensate for deflection. If you are using a forklift mast, it's a good feature to retain, and in turn requires inclusion of a short hose section at the hinge.

Since you intend to lift a car with the mast, I assume you'd be really upset about the consequences of a catastrophic hose failure.

... which is a good reason to deal with a local supplier who will make exactly the hose assembly you need, using compatible hose and fittings.

If you homebrew the hose assembly from random internet sources, and something goes wrong, who you gonna call?

Mike Halloran
Pembroke Pines, FL, USA

RE: hose and fittings question ....

Actually, I am using the lift as an elevator ... I know, scary thought.

It is for personal use so I don't have to worry about liability and such .... wife may kill me but she will not sue me if it breaks.

Even though the original forklift was designed for 3000 lbs of lift, I will have a load of 500 - 700 lbs ( electric wheelchair with a person and maybe an one person riding with them.

I didn't think about the deflection of the mast ( I should have ), I was just thinking they did this because of the "play" in the mast sections.

I am thinking I will load up the car (oh ... car .... now I know why you thought it was for a vehicle) .... sorry, load up the platform ( with solid walls and gate, open top ), with a load ( I was planning on using barrels filled with water ), and see if I can get the unit to lift "straight" up. I want this so I can maintain the clearances between the car and the wall.

With such a small load, I am guessing I will have a minimal defection of the mast. I will find out shortly.

I did order a velocity fuse (hose brake valve). I am (or was ... I will have to see if anything moves when everything is bolted down) planning to hard pipe everything. I was trying to get rid of one more possible failure point ... the hose.

Again, I am overbuilding ( and overthinking ) everything .... I do this on all my projects .... drives people crazy (but this was a good thing and encouraged when I worked in a nuclear plant). There will be no shock load since I have a flow control valve to slowly bring the flow up and down an the beginning and end of the lift. Since the load will be so small, the pressure will only be about 500 PSI. The lift is inside so no UV light, weather or such.

I just keep going over things one by one as I put the system together.

Thanks again ..... Mike

RE: hose and fittings question ....

I'm pretty sure this will end up more expensive than a wheelchair lift you can buy, but it will be a learning experience.

Mike Halloran
Pembroke Pines, FL, USA

RE: hose and fittings question ....

Actually, you would be surprise ....

We started building almost 4 years ago. We had ledge just below the surface. We got a quote for $30k to dynamite the basement out. We got two companies in to give us a quote on an elevator ... two quotes ... $15K, plus we found a grant for $10K so $5K out of pocket. Great, so we decided to raise the house out of the ground. The ground floor is now our basement ( unfinished ), the first floor is now 10 ft up. The price of building a first floor out of the ground was much cheaper that just the $30K to dynamite a basement out. It actually worked out well since we live in VT ( very rural ) ...one side of the house overlooks a small river and the other looks out over a wetlands to the mountains.

Anyway, this year we got both companies in ... both came in close to $40K .... OUCH! Even after a $10K grant, we don't have $30K.

So I bought the forklift for only $850 .... with valves, a spare power unit (for an auto lift ... $500), and a plc to run the flow valve and control the interlocks ... I am thinking $3K to $4K in the project.

I am a machinist by trade and also an electronic controls specialist. So most of this project is straight forward for me. I have interlocks ( so doors are lock when the car is in the wrong location), over travel switches (that kill power, not just tell the plc to shut down), timers to shut off a pump if it runs too long (I saw a contactor weld itself on once and a motor burn up). The main power is two 12 volt deep cycle batteries so it will run even if the power goes out. I have separate batteries for the controls so I don't loose them even if the batteries on the pump go low.

My shop is not built yet (poured the pad last year ... will start it right after I finish this elevator ... wife is getting tired of living in the "basement"). I do have a welder inside the house so I can build the platform.

It is an interesting project ... and I am learning a great deal about hydraulics!

Really, I am sure most of the cost of medical equipment is driven by liability insurance and by insurance. If you look at the cost of anything with the word "medical" on it, it is usually a rip off. If I remember correctly, her last electric wheelchair (it has a tilt function so you can lay back ... to stop pressure soars) lists at $40K !!!!!!!!!!!!! She has insurance thought the state so I am not sure how much they actually paid for it but I am sure it was a lot.

I have learned to build many items myself. My wife need care every 4 hours thus she had never traveled (she broke her neck when she was 12 diving into a pool and is paralyzed from the shoulders down).

Just FYI ... here is a link to an old RV I converted 8 years ago so we could travel ( we ended up living in it for three years ... freezing when temps hit -30) http://mcsele.shutterfly.com/2299

Again, cost driven project .... $18K for the motor home ... they wanted $25K for a lift!

Thanks .... Mike

RE: hose and fittings question ....

Shutterfly says:
To view the photo book, you must have Adobe Flash installed.

Not happening; I gave up on Flash years ago. Sorry.

I'm sure it's a really nice piece of work.

Mike Halloran
Pembroke Pines, FL, USA

RE: hose and fittings question ....

I understand .... Flash is something that still gives me trouble from time to time.

Pembroke Pines ... sounds nice. We made a trip last year ( needed a break between building and moving into the house ) to FL. My wife had never been to Disney ... she loved it!

Maye in a couple of years we will visit again and make it all the way down to the Keys.

She would love to move to FL ... wheelchairs in snow just don't mix.

Problem is her job and insurance is here ... that is why I moved here from SC.

Take care .... Mike

RE: hose and fittings question ....

OK ... so I called Royal Purple and talked with the Manager of Technical Services Department.

He said their fluid is compatible in any case that you would use petroleum based oil.

In fact he gave the example that you would not to use their synthetic oil with EPDM ... but you could also not use petroleum based fluid.

Thanks .... Mike

RE: hose and fittings question ....


I understand you are looking at this as a hobby project. But for the same amount of money you are going to spend refurbishing/converting an old hydraulic forklift you can buy a commercial grade platform lift ($4500). This 600 lb capacity platform lift is driven by an acme screw which seems like a more fail-safe approach than the forklift, and also one requiring less maintenance. It also comes with some nice features like an auto-folding ramp and sensors to detect obstacles below the platform.

Do the wife a favor and install a commercial platform lift that already has all of the design bugs worked out. Save all of your creative energy for constructing your new workshop.

Best of luck to you.

RE: hose and fittings question ....

We actually looked at one of these.

First problem is most (as the one you listed) only go up 8 ft (about 100 inches). We need to go up over 10 ft. This is where there seems to be a huge price jump.

Then they start with the adders.

You will need a motorized gate at the top and bottom .... big adders.

We actually tried one of these at a neighbors. One major problem was the size of the car. There was a legal limit to the size they can sell (I don't remember exactly their reasoning but something about platform lifts has a small size limit than a true elevator) though I do see on the one you found it says 60" optional and that would just work for her. My wife tired a couple of these from different manufacturers ( we even went to a disabilities expo to talk with manufacturers ). Her wheelchair is very large ... electric, center drive (6 wheels), motor on the back for the reclining seat function, ... to get the gate to close her feet hit the front. If I make my own, I can make the car any size I want. 60" literally just worked .... to make it easy for her not to hit each side I am aiming for just shy of 72" giving her 6" of clearance at each end.

And then there was the speed. I now they list 10 FPM ... not sure if that is realist .... most of the ones we saw were much slower. Not bad if you are going up 3 ft but 10 ft takes forever. I installed one of these last fall for an older neighbor ( found a used one for $1000 ). It was just to get her in the house ... about 3 ft up. It worked great for them. As you said, ramp folded up in the back to stop you from rolling off ( if you look at the one I built for the RV, I used the same idea ), the stop sensors are micro switches on a spring loaded plate on the bottom. The two biggest problems they had were 1) I still needed to put up a gate at the top so on one walked off the platform (in there case, I just used a chain) 2) the second problem was they had to load her one, run around the house since even with a manual chair they could not fit on the platform with a person, and meet them at the top. Again, my wife tried it and just could not fit on the platform.

The big jump in price the companies told me was 1) because we are going up 10 ft ... so you need a very heavy acme screw 2) automatic doors ... two stop stations both with electric doors that will interlock ... my wife could not pull in and then close a door/gate behind her and would not be able to open one that is behind her when she gets to the top.

I have built the house to give my wife a maximum independence. Even with no use of her hands, two years ago she learned to drive. She now had a van that she can get in and out of herself. For the first time in her life, she has the freedom to go where she wants, when she wants by herself. I want to make sure she can use the elevator completely on her own.

Really, these lifts are great to get up and down a couple of steps and have a small chair.

I do appreciate the advice thought .... it would have been much easier to just buy one if I could have found one that worked for us.


RE: hose and fittings question ....

100R12 IS a 4000 psi, 4 wire isobaric hose that maintains the same pressure rating across all sizes. This hose was engineered for a torquing and twisting inviroment and still maintain a high isobaric pressure rating. This is found on harvesters, porters, excavators... This would most definatley be over kill for your application.

100R18 is a thermoplastic hose that commonly refured as lift truck hose fore its use in forklift lift cylinder tracks. This isnt what your looking for.

100R2 Is cheap, available everywhere amd high pressure ratings with smaller sizes. sometimes the simplest thing is the right thing.

However, if your operating pressure is sub-3000 psi and your looking for a little more flex. Go with 100R17. This stuff is great for compact sitsuations where plumbling is a nightmare, or truck plows that are contantly moving in all directions.

As for bite to wire or standard hose fittings. I believe what your asking is skive or no skive fittings. People have been skiving for years but in the last 10 or 15 years, most major manufacturers have started there own no skive fitting revolution with the development of no skive ferrules for pressures up to 6000 psi. Make no mistake, these fittings are 1 million impulse cycle tested just like there skive counterparts. But ease of use, and no need for skiving tools allowed these fittings to become a hose makers choice. That being said, in pressures over 6000 psi skive fittings are still th only way to go.

RE: hose and fittings question ....

Awesome explanation!

It is funny how the suppliers can not tell me this information. That makes complete sense!

I did find out a bit more about the bite to wire or standard fittings. Both are no skive. There web site says: These hose ends are similar to Parker in that they provide a deep bite crimp into the rubber hose using steel “fins” inside the ferrule to dig into the rubber hose and “bite” into the steel braid or spiral

It suggested that these can be used on any hydraulic line (even two wire) but are "made" to be use on heavy duty line such as 4 wire.

As you may have noticed from my postings, I am a true "pain in the butt" (just ask my wife). I hate making any decision without a clear reason. I was the kid who always ask "why"?

Thanks so much again ..... Mike

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close