Any Tips on Building Hydraulic Reservoir

[shaley]

I thought I'd build a 20 gal reservoir for my PTO pump. any suggestions. I was going to use 12 ga sheet and fold it into two "U" shaped pieces and invert one to form the top and sides and weld it up. Should the outlet be right at the bottom or slightly raised to keep water out of the system?

 

[MossRoad]

One thing I have heard is that you can get an eddy current running inside the reservoir where the fluid pretty much goes in a circular pattern from the inlet almost directly to the outlet, so that much of the fluid never exchanges. You don't want that. You may want to look into some type of baffling to disrupt the flow so that it constantly mixes the fluid so most of it is used. Just don't mix is so much that it makes foamy waves at the top of the tank.

If possible, look inside a reservior on an existing unit. You should see some baffling.

 

[Farmerford]

Raises the outlet at least a couple inches off the bottom and size the bulkhead pipe bung to take a screw in mesh screen with bypass valve.

Return line fitting should be a few inches below minimum fluid level to reduce areation and a diffuser should be installed to prevent full stream from discharging directly: a short length of 1" or 1 1/2" diameter pipe, drilled full of 3/8" or 1/2" holes, capped on one end, with the other end welded to the inside of the return pipe bung works.

Divide the tank into inlet and outlet sections with a baffle that runs all the way from the bottom to the minimum fluid level and don't put holes in the baffle. Fluid gets from the inlet side to the outlet side by flowing over the top side of the baffle. The object is to keep the incoming fluid as "quiet" as possible so that particles will settle out in the inlet side of the baffled tank.

Include a cleanout at the top that lets you reach your hand into each part of the tank.

Put a fliud level and temperature guage on the outlet side of the tank (with a full baffle, fluid can be low in the outlet part of the tank, but still up to the top of the baffle in the inlet part).

Put a drain bung in each part of the tank.

Use a fill fitting with a screen to keep out rocks.

 

[tommu56]

Most of the tanks we have at work have a baffel in them it keeps aeration and big lumps out of suction and they have suction strainers on them simular to this

Suction Strainer | Hydraulic Accessories | Northern Tool + Equipment

The inside of baffel overflows (like a dam) to suction side and there is a clean out and drain on each side .
tom

 

[shaley]

Thats for all the tips guys. A lot of good ideas and some I had not considered at all. I did buy the 2" NPT suction strainer from Northern. I hope I can get time next week to go by the sheet metal shop and have them shear and press break the metal.

 

[Farmerford]

Steve:

Consider putting a pressure (vacuum) guage in the suction line to make sure the vacuum does not exceed 3-5 psi, which is generally accepted as the maximum vacuum at a pump inlet that can be accepted without causing cavitation. Your pump may have different specs. The guage is particularly important if the screen you bought does not have a 3-5psi bypass valve to allow fluid to pass around the screen if it gets clogged.

If you have not bought your filtration system, consider using "absolute" rated elements (probably 5 or 10 micron) rather than "nominal" rated elements. Absolute rated elements are much more expensive, but for a 10 micron filter, for example, the absolute filter catches (typically) 98-99.5% of the 10 micron particles in the fluid while a 10 micron nominal filter will catch around 50%. If 200 10 micron particles are in your 20 gallons of fluid, 100 of them will remain after one pass through a nominal 10 m icron filter, but between 1 and 4 particles will remain if the filter is 10 micron absolute. Absolute filters do clog quicker (naturally), but you can get a bit more life from them by selecting a filter mounting with a 30-45 psig bypass valve.

If an element is advertised as merely a "10 micron" filter, it is almost certainly a nominal rating. Virtually all filter manufacturers make nominal and absolute rated filters, and they are proud enough ($$$) of the absolute ratings that they will call them "absolute" rated when they can. The cans look the same; the difference is that the absolute rated filters typically use a synthetic filtering material that is much more expensive than the less effective (and often natural, such as cellulose) material used in the nominal filters.

 

[CATMAN]

Need to provide a vent for expansion at the filler cap or top plate. This too should have a filter on it. Suction lines are generally larger than any pressure or return lines, so factor that into your fittings on the tank (you probably already knew these things).

 

[Wayne County Hose]

For the price of one, I don't know as if I would bother. Unless you need some kind of custom configuration. Way too much in time and materials. Plus, the guys that make them know exactly where to put the parts for optimum efficiency.

 

[sandman2234]

I would sit down and figure out the best way to shear/brake it to reduce the number of welds, especially at the bottom. Two U shaped will have 10 sides to weld, but a single piece broke into a square box will only have seven sides to weld. Quite a bit of difference in weld time and materials, plus a lot less to chance of it leaking at a weld.(I know that your welds don't leak???)
Years ago I build an aluminum gas tank for the guy that built the house I live in, for the generator in his Greyhound Bus conversion. He didn't want steel, so I priced stainless, since I couldn't weld aluminum. After getting that shock, I farmed out the brake and welding to a couple of shops using aluminum. I picked the welder because I knew he did good work. I even called Miller to confirm the welding machine would do the job.(Al.MIG) Job got finished and I filled the tank with water. Leaks, fixed it, more leaks, in places it hadn't leaked. Took it to a different shop, with a TIG, but it still leaked. I completed welding school and purchased a TIG for the house and painstakingly filed all the welds, and went carefully over them 100%. Finally got it finished way past it's due date.
The bus owner passed away and the generator out of the bus misteriously disappeared, so the guy that bought the bus purchased a diesel generator. The gas tank was removed to save space so my liability was limited. I visited a farm of one of the people involved in the settlement of the estate and ironically he had purchased the same exact generator, even with the hole drilled in it for a bolt I needed to secure the gas tank. Hmmmm....
Consider flooding the tank with an inert gas while welding to reduce the slag and scaling on the inside of the tank. Some sort of petro resistant epoxy paint would also be nice inside it if possible.
David from jax

 

[Mith]

You want the reserviour to be tall and thin rather than short and fat so that when you are on a slope all the fluid wont run down to the lower side and starve the pump.

I fabricated mine from stainless steel sheets. Cut them all the size and shape and welded them together. Got it leak free with only a couple of tries, filling it with water and seeing where the leaks occurred. Ver time consuming, but I got the shape I wanted.