Weird shulflo issue

[boondocker]

I'm running 3 different 4008 shurflo pumps on 3 different locations. My issue is on the hill with 100 taps. The pump will pull almost 28" but every now and then it stops pulling sap thru the pump. The pump dosent stop running it just stops pumping. It's almost like it vapor locks. It has done it quite a few times over the past few weeks and yesterday I was working on the main line, I added a sap ladder and when I walked back down to the tank the sap was backed up about 150 ft. Up the main line. I I shut it off and waited a few minutes and starated it back up and it puts sap thru for a few minutes and then it did it again. It never lost vacuum once. I had a brand new pump in the sugar house so i put that one in thinking maybe the pump has just had enough of me. So this morning I go over and turn the pump on, and it pumped perfect and built up to about 19" and this new pump did the same thing. I just disconnected the filter assembly on the intake side so the main line goes directly to the pump and not hru the filter. So far so good but was wondering has anybody else has this issue? I can't imagine that stupid little filter assembly is causing my issue but I have been wrong before........many times......ask my wife she will tell you!! Just realized my phone spelled shurflo wrong on the heading......sorry about that!

[gmc8757]

I have been struggling with the same exact issue the last couple of weeks on one of my shurflo's. I removed the filter screen and continue to have the same issue. Maybe I need to remove the assembly housing. Thanks for the advice, I'll give it a shot.


Sent from my iPhone using Tapatalk

[boondocker]

Yeah I just checked it again.....still going .....strange! One of my other setups has 98 more taps then this one, never put a filter on that one this year and never had a issue.

[Wanabe1972]

You have a good tight system and the trees are not running hard enough. On a marginal flow day I watch my little pumps pull sap for a while and then all of a sudden the sap is running backward. This is not happening on the 98 tap line because there is more sap to be drawn and the pump is not running dry. If your filter is not plugged and doesnt leak I don't think this is the problem.

[boondocker]

It's definitely a tight system, there is more sap running thru that system then there is on the system with more taps. It definitely has plenty of sap running to it. When the pump stops pumping it backs up in a 3/4 main line about 3 ft in a matter of seconds so it not a matter of sap getting to it. I just checked it again, it's pulling 24" and running perfect without that filter on there.

[BAP]

Mine does the same thing. I solved it by putting a recirculating line into the tank with a needle valve to control flow. I adjusted it so that at the high vacuum it keeps pumping constantly. I found before using the line that when it stalled pumping sap that it would not pick the flow back up again until the vacuum dropped but as long as sap keeps going through it will keep going and bring in a lot of sap.

[Atgreene]

My 112 tap system is locking up, just can't pull the 3/4" lines down, it gets airbound then stops until it builds up enough sap in the lines, then runs like made full stream for a minute. Then does it over again.

I added a recirculation line, jumped to 22", getting more sap.

[sapman28]

You need a recirc line to keep the diaphram wet.

[gmc8757]

You need a recirc line to keep the diaphram wet.

I have a recirc line. When I open it wide open, the pump has a full stream coming out but sends even more up the mainline. If I close it real quick, it will suck it all back into the tank but then starts backing up again.

I try running it with the recirc valve slightly open and have the same issue with Sap backing up.


Sent from my iPhone using Tapatalk

[Biz]

How does the recirculation line work when tank is empty or frozen? I would think there always needs to be sap in the bottom of the tank (not frozen) for this to work.

I have a line that does something similar under low flow conditions. It was fine at the beginning of the season when flow was high but not as good now that flow is less.

Dave

[maplemas]

Did you add a check valve ? I put one on my guzzler right after the filter and started having the same issue... removed the valve problem seems to be solved..

[BAP]

How does the recirculation line work when tank is empty or frozen? I would think there always needs to be sap in the bottom of the tank (not frozen) for this to work.

I have a line that does something similar under low flow conditions. It was fine at the beginning of the season when flow was high but not as good now that flow is less.

Dave
I have my tank set with a slight pitch so that 2-3 gallons will make a small pool in one end and I put my recirculation line in that end. I have a tee off my mainline with a needle valve with a piece of 5/16 tubing with a connector on the end with a cap on it and a small hole pierced in the cap. I also taped a small weight to the connector to keep the end submerged in the sap. As long as there is an inch or more of sap, there is enough for it to keep recirculating.

[boondocker]

OK so it did it again, I went over tonight to check it and it was passing sap but just a drizzle. I walked up to the sap ladder and all 6 lines where full and right to the top but not flowing in. I looked at the main line on the bottom of the ladder and it is completely full. I started walking up the main and it is full, I mean completely full of sap for at least 200 ft. The vacuum gauge was reading 24". I cannot believe 24" won't pull sap 4' in the air and pull it down hill. I released all the vacuum and turned the pump back on and bam it took right off and started lifting the sap. I'm going to add a recirculation line tomorrow and try it......this system is getting a gas powered vacuum pump and a releaser for next season. I firmly believe I'm leaving a lot on the table as far as sap yield on this location. I'll update tomorrow as to wether that fixed my problem or I set it on fire.

[boondocker]

You I have been thinking, this issue started after I fixed 2 vacuum leaks on two separate laterals.......now that the complete system is basically 100% tight this issue is happening. Coincidence??

[Cedar Eater]

It almost sounds like you should experiment by putting a needle valve at the top of your line to let just enough air in to keep the sap moving. I'm not sure that will help you pull more sap, but at least it won't just be sitting in the line.

[asknupp]

I'm by far no expert nor do I have any vacuum yet. But after reading on here daily I think people with sap ladders create a micro leak at the bottom of the ladder. The bubbles from micro leak is what creates the lift for the sap.

[sugarsand]

Dont know if this will help with your situation, but dont write off your shurflo quite yet. We have been using 12v pumps for two seasons now. 5 are 12v 4 are air driven, the air driven work better by far. All pumps were set up with a recirc line, using what ever cheapy valve I can find. Last year I didnt need only a very little sap from the tank, but this year the valves at times need to be 1/2 to 3/4 open. Im thinking that most of this is the poor sap flo that we've had. Tweak the valve to create the fastest flo by watching a bubble. Some days bubbles would only bouce back and forth, thats when I shut the pumps off because the trees arent giving up any sap. If you think there is a problem with the pump, turn it off and open the bypass to see if there is any gravity flo. Something else to consider is many of these pumps have short diaphagm life. Im already planning to switch some of the 12v to air driven next year.

[boondocker]

I appreciate everybody's input here i truly do. I'm kind of on the fence right now as to wether do the recirculation line or give it a small air leak just before the sap ladder. I know it's definitely not a pump or diaphragm issue because the pump that is on there right now is a day old and is doing the same thing as the 2 year old pump. I would much rather do the recirculation line v.s. the vacuum leak only because the system is so tight I don't want to drop my numbers. I'm going to run to Lowe's and get some hardware and go all redneck on this thing and make it work. We had a decent freeze here last night and it is supposed to be 47 today so I need to make it flow wile the sun shines. If anyone has more pictures of there recirculation setups I would love to see how you guys set them up to use as some guidance. What size line are you guys using for the recirculation?

[RileySugarbush]

sugarsand: What air pumps are you using? What kind of vacuum do they pull?

[sugarsand]

Weve been using Amarine brand. These are 4L/m, 12v. I think they draw about1.3 amps. This size works good for us in area that have 1 or 2 lines coming to it but they would handle more. Can buy them on ebay for around 20 bucks, and these are new, not used.

[sugarsand]

Sorry Wiley, just noticed you were asking about the air pumps. Started with Flojet brand. Tried to differant styles, had the best luck with 55 series. Have 3 of these that work on our air compreser in the garage. Placed one in a area where we 150 taps feeding into a 1/2 inch mainline, this spot is always muddy to get to, so I have a second pump that lifts sap about 10 feet then runs to the shanty. The third 55, I'm using on a 35 tap line. Once it builds a vacuum, it only runs when it needs to build the vacuum up as the sap runs in. On a tight system you can get 20 to 25 inches of vacuum.

[Cedar Eater]

If anyone has more pictures of there recirculation setups I would love to see how you guys set them up to use as some guidance. What size line are you guys using for the recirculation?

I just tee into the suction line right near the pump and run a 3/16" line (with a 1/4" ball valve near top) down into the collection barrel. It's a loss of efficiency, but it keeps the pump wet and that keeps the vacuum reading up.

[asknupp]

Boondockers look in the threads for "sap ladders to steep" flats knows what he is doing too

[whity]

We are having the same issues in our groves. We have 2 on 4008 and 1 on 4048. I was wondering if a PVC manifold/releaser would solve this issue of backing up?

[Ultimatetreehugger]

I found cleaning mine with deluded vinegar and warm water every few days stopped this issue. Just use a bucket or tub, hook your inlet to a hose and run your pump for 10 minutes. Rinse with water the same way.

[CampHamp]

If your pump hits an air pocket when there is vacuum in the lines, it won't be able to pull sap/air until the pressure drops. The trick is to keep it "wet", otherwise you get this stall/start pattern and lower vacuum.

Others noted the recirc technique. I tried that and I guess it makes sense for start-up or very low-flow days. However, if the trees are running and you get this stall/start pattern, then I would expect that either (1) you don't have a gradual down-slope to the pump's intake to let the sap constantly trickle in under the air (air over sap along the entire mainline is crucial) or (2) there is a leak at the pump which should be easy enough to identify, if you see air moving backwards away from the pump (sometimes air moves backwards when sap rushes ahead, but that shouldn't occur if it is gently trickling in).