.Get a crane.... Hydraulic oil is moderately flammable when cold but you'll never get the metal clean enough for a good bond anyway (with fluid in it).

if it was me, I'd pull it and install an bulkhead fitting anyway. Maybe it needs an inspection cover added for access.

 

You are going to need to clean the inside of the tank after you drill the penetration in it. Hydraulic pumps and components are not very fond of metal particles.

 

It's a tank feeding different pumps that are not mounted directly to the tank?

Make a new tank for the new ungraded pump. Leave the old tank feeding the ones it's hooked to.

Minimal down time.

Dave J.

 

Reminded me of the time I dumped about 100 gallons of hydraulic oil in a gravel parking lot (I had a main line break on a rolloff when I was pulling a heavy box of scrap). It emptied the holding tank in about 5 seconds. The plant manager was going crazy about the oil.

I told him, one it keeps the dust down and two, it supposed to rain tomorrow, it will be gone. Hydraulic oil dissipates in water...... quite nicely.

Not sure if dropping the level and welding a port in the tank would cause it to explode but I'd pull it anyway or fab a replacement beforehand and switch it out.

 

I would like to build a new one but this thing has about 16 ports on it, internal filters, baffles, and other things on it. I know they weld on main gas lines live just trying to figure out how its done. as for the fitting I can weld it to the outside before the hole is bored so its just welded to the outside of the tank

 

I know they weld on main gas lines live

The issue is that when you weld a weldolet or the similar to a pipeline, the gas in the pipe is pure natural gas and is not flammable, because there is no oxygen in the pipe. You'll be welding on a vessel with oil fumes and a combustable pressurized atmosphere.

A very different thing than a hot tap

 

Cut about a 4" circle out of 1/4", drill holes around the outside for 5/16 bolts every 3" or so. Weld your fitting into the circle. Drill and tap corresponding holes in the tank and hole saw a center hole to fit in the fitting. Make a gasket with some silicone on both sides and your set.

 

Where are all the cuttings going to go when you drill and tap the holes in that tank?

 

I knew someone here would have a duh fix for it. thank you welderj that will work perfect.

 

Glad I could help. Done a few that way over the years. Just to clarify on the gasket make sure you make a gasket out of materiel you can get at the auto parts store, just silicone won't work well.

 

If you find the closest weldolet to the size of your out put pipe, You can weld it on the tank and then hole saw right through the weldolet. Ive done it more than once. The small pieces of steel that fall in the tank will be picked up by the filter or just lay on the bottom. The hydraulic fluid will boil a little at the weld point but it dose not carry heat away real well so you do not have to worry about hardening the tank. Mac

 

most of the cuttings will flow out when the bit passes through I already have dumped about 40 gallons of oil on the floor from leaks(this is a new rig to me and we are doing all the repairs from years of abuse and from a couple of years of sitting). A couple of big magnets on the base of the tank aught to trap everything else right?

 

tool maker I was worried about having a poof, my wifes a widow moment. when you did those was the tank full of fluid above your welding point or was it below I can fill the tank back up above the port height if needed? its a pressurized tank very little air movement when the compressor is not running. there is over pressure relief but no fresh air intank without the rig running

 

When you are drilling (not welding) the tank, put a strong magnet on the tank just below where you are drilling or threading. It will collect the chips for you. It will collect the chips inside too, but this will only help if you have an access hole to remove them through, but in my experience, very few chips will be found inside of where the magnet is located. They almost all seem to accumulate on the magnet outside.

Charley

 

. . . the question is how can I weld a bung on it while it has about 20 gallons in it. . . .

A lot of good suggestions have been posted.

Back to the beginning... Why bother fighting over 20 gallons?
Drain, or pump, the fluid out. The fluid will leak out anyway (down your arm! ) before a flange install can be completed.

How 'bout supplying the pump VIA a dip-tube installed through the top of the reservoir?

Last question: No suction strainer?

 

I have done this to a few tanks myself but some good ideas here @ tool maker I would never trust a hydraulic filter to pick up rubbish out of a tank as a lot of hydraulic systems are filtered on the return which meens the oil will have already passed through the full system ( not good with metal shavings in the oil) I used to do a lot of this work for JCB dealers in Scotland any welding on hydraulic tanks was done with oil in the tank open cap and go at it never had a problem (yet) as for drilling the hole I have a selection of old speaker magnets which I slip inside my hole saws they catch about 90% of the shavings . Then a magnet tool one of the telescopic ones is put through the whole to collect as much as I can and always flush the tank with diesel afterwards always been good never a fault so far let us know how u go

 

I'd purge the tank with an inert gas before and during welding, would eliminate the concern of the oil being vaporised and exploding. I've welded a few diesel tanks up and never had an issue doing it this way

 

+1 550, nitrogen purge or dry ice would work for this application .

 

I filled mine with co2 before welding on it, had no troubles. Hot tap on a gas line is no different, it is just that you have air in your tank. Replace the air with inert gas and it is the same. Only difference is that you don't have the tools that they use to actually do the tap portion of it, could make them fairly easily if you knew what they were and how they worked.

 

I got it welded in. I drilled it out and took the wirefeed bottle plumbed it in and let it run for a 100PSI worth then welded it over a 15 minute stretch with 1/16 +P rod had just a little flame were the oil would boil over and leak out the unwelded part of the weld outlet. a new computer to me so Im having issues with the pictures. thanks for all the advice and help

 

I got it welded in. I drilled it out. . .

Great!

So did you drain the oil or work through it?

 

Hydraulic tank size is primarily determined by the required cooling capacity for the horsepower of all of the pumps feeding from it. Adding a cooler reduces the size requirement of the tank. Have you considered adding a fan cooled oil cooler instead of enlarging the tank?