Welch 1402 Turns Tight

[Springfield Acer]

:confused: I got my new home made releaser and used Welsh Vac pump hooked up in the garage today for a test run. It ran right up to 27-1/2" and drew water from a drum thru 5/16 tubing and dumped. During the dump, the pump stalled at 0" and the motor pulley was slipping. I tightened the belt which is old and glazed and that helped but not much. I still had to press a smooth handle against the belt to get enough tension to make the pump turn. Then the motor's overloads shut it down. I removed the belt and found the pump was quite stiff to turn over. I don't care to just jump right in and tear down the pump without some more informed advice. Any comments?

[Springfield Acer]

I've been running this through my mind all day. I am now wondering if my garage test is the problem since I get to full vacuum for only a couple minutes and then dump. This would be a far faster sequence than out in the woods. Maybe if the pump ran longer at the higher vacuum, it would cool and be ready for the next dump.
Is this possible?
I am going to dead head the pump and see how long it runs.

[325abn]

Got any pics of your homemade releaser?

[G.Rainville]

Did water get into vacuum pump?

[Springfield Acer]

G Rainville;
No water. This pump has been sitting empty for years. I filled it with oil right before I started it. After the troubles, I drained some out and all I got was nice clear oil.

325 ABN:
Check this thread: http://mapletrader.com/community/showthread.php?17317-Homemade-Releaser&highlight=home+made+releaser
I made the same on. There are pix early on in the thread.

[lmathews]

You should try to run the pump at less vacuum and let it warm up and get oil back into some of the bearings and loosen up some of the old gunk build up.Try that then slowly increase vac and see what happens.

[Springfield Acer]

The manual says that this pump will overheat if it is run at high pressures (little vacuum) for very long. I'm concerned that my testing ia actually already doing this.
My next step may be to do the opposite and dead head the pump and let it run for a while.
We'll see.

[jgrenier]

I am having the same problem with a welch 1397. I am not sure what the fix is yet

[Springfield Acer]

I ran a dead head test which should be the easiest operating condition for this pump.
The 1/2 HP motor is rated at 9.0 amps with a 1.0 SF.
It started cold at 14 amps and over about five minutes it only dropped to 9.2 amps (still above the rated amps).
Over the next ten minutes, it slowly climbed and finally shutdown on its thermal overload at 14.1 amps.
Again, the pump was difficult to turn by hand.
There is a process of doing an inlet flush with a cup of oil over 20 seconds. I guess I'll give that a try.
I've looked at the exploded view and am having difficulty understanding what is getting hot and causing the tightness.
The manual says to not run this for extended periods above 10 Torr which appears to be 0.40" HG which would then equate in absolute pressure to ~ -29.5". My pump dead heads at 28.5. Maybe that is the problem? I don't see how since many people use this pump for sap and nobody is running consistent -29.5".
Or,......maybe the pump just has enough rust and gunk accumulation over many idle years with no oil in it that it needs rebuilt. I'll bet that's not cheap.

[schellmaple]

I have this same pump and I had some of the same problems. I called the factory and they said that they put phenolic vanes in the pumps and when they sit for a long period of time they dry out and swell causing them to run stiff. I took the pump apart and sanded the vanes with some emery cloth untill they moved freely in the slot. When you go to put the pump back together make sure you put a thin coat of oil between all the parts. This will give you the correct clearence on the moving parts. If needed you can PM me with your email and I can send you a copy of the user and parts manual.

[Springfield Acer]

Thanks Schellmaple. That could very well be it and absent of any other info, that will get me moving to do a tear down. I have the mfr's parts and operation manual already unless you have a factory service manual. Can you get this apart and back together without any gaskets?

[schellmaple]

I was able to tear mine down and put it back tgeather without changing any gaskets or orings. Whatever you do don't forget the thin layer to the parts when you reassemble or you will have to tear it back down.

[Springfield Acer]

Well, I tore mine down tonight. Right away I found the shaft seal was stuck to the shaft. This was either dried on over all the years of idle time or melted on but it looks like it was dried on. I find it hard that this seal was able to bind the pump. If anything, I would have expected this to smoke like crazy. Everything else inside was very nice looking. The vanes moved freely. No signs of wear or heat or galding.
All the gaskets were ruined by disassembly.
Now I've got to decide whether rebuild it with just new gaskets and seals for $90.00 or with new vanes for $250.00 plus new oil.
Obviously I want to get this running and not tear down again. I suppose I'll spend the money.

[Springfield Acer]

I did end up buying the full rebuild kit but I just got around to reassembling it tonight. It ran for 30 minutes at 28-1/4" before I shut it off. The amps also came down to below the motor FLA. I'll run it more tomorrow with my releaser mocked up as a bush system and see how it continues to perform so that it is hopefully ready for next season.

[schellmaple]

I did find out this year that if my oil level gets high in the pump is starts running stiff. The pump must accumulate some condensation over a period of time. I just drain some of the water out and it seems to run better after a little bit. I have a mostiure trap but it must not get it all.

[Springfield Acer]

I did find out this year that if my oil level gets high in the pump is starts running stiff. The pump must accumulate some condensation over a period of time. I just drain some of the water out and it seems to run better after a little bit. I have a mostiure trap but it must not get it all.

If you get enough water to raise the oil level, your oil must be pretty cloudy. If so, do you just run it that way all season? Do you drain it out and refill with new at the end of the season?

[schellmaple]

The oil does get cloudy and I should replace but I just drain off water and keep running the pump. I think the pump is designed to handle some mosture.

[BreezyHill]

Hot pumps can handle a tiny amount of moisture, as they will dissipate the water out the exhaust. Many sap water traps are built backwards and wil pul in water vapor. A simple pvc design using 3" tee will suck the air from the outer edge of the vessel, with the inlet coming in the top of the tee and down a tube on a 2" reducer. This forces the water to impact the bottom and the sidewalls will be cooler and form condensation. Install a float valve and a contactor for the motor and you can put a swing check on the bottom and the unit will shut off the pump and back on when empty.

Use a nonfoaming oil like vac oil and the water will separate in the pump body and not be an issue for draining.

I rebuild dairy pumps and usually heat is due to vanes rubbing on the housing. Sticky vanes at high rpm are usually the issue. Sticky caused by low quality oil and buildup on vanes. Occasionally pests come into units thru exhaust system. Always have a screen off exhausted. Sucks pulling insulation out of a pump.

Good Luck!

[Springfield Acer]

I have been running my pump and releaser yesterday and today. I have a drum of water set below the releaser outlet. I have a piece of 5/16 tubing in the drum that is on the releaser inlet to simulate drawing on my tubing system. I have tired the tubing wide open and the tubing pinched off a bit with a pair of Vise Grip so that I draw anywhere from 4 gpm to 1 gpm. My pump has a pretty good vapor coming off of it and the casing reads as high as 165* after four hours operation. Since this is my first vacuum experience, I do not know how normal this is. As I write this, the pump has been running in the garage for 4-1/2 hours and I am planning on letting it run until I go yo bed after the Penquin - Rangers game. I am curious to see if the temperature levels off. I get enough oil vapor that a bit of oil is collecting on the casing top and running down and dripping occasionally off the bottom. I run 26=1/2" shortly after each dumping.

[BreezyHill]

165 to 185 is not a bad temp. When the oil from a reclaimer is above 200 it is time for concern and steps to lower the temp.

I am not familiar with the design and internal workings of this pump but a simple transmisttion cooler and small fan can easily be hooked to most units to lower oil temp and setup with a electronic controller to operate the fan when oil temps get to high.

Vac oil is an excellent cooler as long as a reclaimer is used. The oil vapor from a flood or dripper will cool the housing and oil is then recurculated from the reclaimer after it condensates and the heat is dissipated.

In your system you are cooling the pump by the food of air after each dump. The flow of air thru the pump after the dump will cool the unit. If the dump is more often the cooler the unit the longer between dumps the higher the dump. So on a warm day the higher usual flow of sap will keep the unit cooler with the more frequent dumps of sap.

On the other hand on a cool evening and the unit is pulling higher vac with seldom dumps the pump temp will often jump as there is little to no free air to cool the pump.

I like 185 for my units. At this temp I don't get the internal corrosion from trapped vapor, the bearings stay nice and shinny. I do run a fan to cool the pump if the unit gets to warm and has not been modified with flood oil. Units that I rebuild have more internal oil flow and I add a dripper to the inlet side if needed.

Nice thing about vac is if you set the dripper at a low point of vac say at peak flow and your releaser is cycling rapidly; when the flow slows and vac increases then you sill pull more oil for cooling. Same is true about the hot oil will pull and flow quicker thru the drippers than cold oil.

Drippers and motor oil or other oils that foam are a recipe for disaster. The sludge will plug the dripper and the unit will seize.