air relief valve for top of sac?

anyone have any good ideas for an air relief valve? maybe the type that allows the air to escape until liquid hits a float or something?

pipe a vent hose out with a check valve. Stop pumping once the water goes out the vent hose.

that is what i currently do, but a no fuss valve would be cool also.

Interested to hear, too. I was thinking to just use a small diameter tubing - if you could see a little high-pressure stream shooting out, you'd know it was full. Keep it simple, right?

some thing like this...but would it stay closed?

Nylon Diaphragm Control Float Valves
• Maximum Pressure: 130 psi @ 70° F
• Maximum Temperature: See table
Control water levels without an assembly. Valves are self-contained and have a diaphragm to allow full flow until water level rises. As water level rises, the internal float closes the diaphragm to shut off the flow. Valves are small (3 3/4" Dia. x 5" Ht.) to fit in tight spaces. Body is fiberglass-reinforced black nylon and diaphragm is silicone. Internal parts are ABS plastic and Type 304 stainless steel. Valves are for in-tank mounting in open tanks. Flow rate is 70 gpm @ 75 psi.
Connections: 1" NPT female.

Check out the Fluid Concepts sacks. They have a long tube that comes off for air relief.

http://www.fluidconcepts.net

You can use a washing machine water level valve to shut off the pump when the sac is full, the cost about $10. I have one that I am going to try when I have time. It's not a bad idea to use it as an overpressure savety for locker sacks.

too expensive for my application but should work...


Air Venting Valves
• Maximum Pressure: See table
• Maximum Temperature: 210° F

Brass

Polyamide

Designed for heating and cooling systems that use water, these valves automatically vent air to eliminate air pockets that can reduce system efficiency. Install vertically. Choose brass or polyamide valve body. Connections: NPT.
Brass -For hydronic (water) and other liquid air venting. Brass body with a Monel spring and neoprene seat resists oil and antifreeze.
Polyamide -For use with water. Not for use with oil or oil-based additives. Valves have a brass base and thermoplastic body, float, and cap for excellent corrosion resistance. Vent for heating systems has Buna-N disc and O-ring. Vent for water purification systems has EPDM disc and O-ring.
Pipe Size and Max.
Outlet Location Pressure Height Each

Brass for Hydronic (Water) Air Venting Systems
1/8" Female Bottom 75 psi 4 3/8" 4928K1 $18.42

1/8" Female Bottom and Side 75 psi 4 3/8" 4928K2 22.29

1/8" Male Bottom 75 psi 4 3/8" 4928K8 21.27

1/4" Female Bottom 150 psi 4 3/8" 4928K3 21.47

1/4" Male Bottom 150 psi 4 3/8" 4928K9 21.69

1/2" Female x 3/4" Male Bottom* 150 psi 4 3/4" 4928K4 27.25

Polyamide (Thermoplastic) for Heating Systems
1/8" Male Bottom 90 psi 5 1/4" 47225K63 18.55

Polyamide (Thermoplastic) for Water Purification Systems
1/8" Male Bottom 90 psi 5 1/4" 47225K83 20.40

* Inlet x Outlet.

i found what i was looking for and will test it and let you know.. in theory this should work like a champ for $1.50 delivered.

.................................................. ....Flush Valve
This flush valve opens when line pressure drops below 2.5 PSI. It can be installed at the end of a drip line using a CE or an ELMH or at a low point in the middle of a line using a CMT or an ELMT.
When installed on the bottom of the filter it serves to automatically flush sediment from it. When installing drippers or sprayers in hanging baskets it is a good idea to install a flush valve into the vertical feed line a foot or so below the horizontal feed line. This will prevent prolonged dripping into the baskets.
VFH Female Hose Thread $.95 Qty:

VFP 3/4"
Female Pipe Thread $.95 Qty:

Yes please let us know. Would be awesome if it worked the way it should.

Ty, did you ever try this thing?

i actually find one from the same company that looks just like this but is .5 lb psi. i tested it and it lets a little water out but as soon as the sac gets full and tight it did close perfectly. they are very cheap also.

Cool, where did you find these things?

www.dripworksusa.com/store/ freeze.html
but call them and ask sa they do not have the .5 on the website

Awesome. Thanks a bunch.

So are you SURE this is the best out there? J/K, I think it will be good enough for me if found by the most thorough researcher around...

lol. the price is right also. all the other ones were big dollars. for the price, why not give it a try. it worked off of a hose and probably better off of a pump. a pump would fill faster than a hose therefore close faster.

Here, check this out:

http://www.attwoodmarine.com/Products/parts.asp?ProductID=577&path=fuel&category=5&gtype =2&group=0&subgroup=0&categoryname=Fuel+and+Motor+ Equipment&typename=Built%2Din+Systems&headername=F uel+and+Motor+Equipment

(hopefully that long URL won't get cut up...)

This is meant to stop fuel from spilling out the vent line. It is installed in the vent line and has a float ball trapped inside that when the fuel fills the chamber the ball floats up and closes the exit port. It must be installed within 45 degrees of vertical in order for it to work.

I installed these on the big cruiser I used to own and I can vouch that they do work for preventing fuel spills. I am not sure they would seal well enough to prevent leaks over time.

But like Jason said, why not just pipe the vent line a few inches higher than the top of the sac and let it overflow?

how much is that and how would it install in a line?

also where can you get those and what is the lengeth of that part?

Why not try something like this?

3/4" Elbow
3/4" Garden hose female attachment
3/4" hose to valve Brass converter
3/4 Ball Valve

I screwed the elbow into the bag with LOTS of caulking to seal it up good. I also screwed in two SS screws (1/4") into each side of the threading on the elbow to hold it in good.

1 Day in the sun, and it was dry and good to go. Now I have fill and granular control of the air and water. It also allows a easier attachement of the pump hose. Water flow is good and fills in a few minutes from a 750GPH pump.


KG

i did the very small hose fitting ball valve like that. half the size and put it on a hose barb with about 6 inches of hose on it. I stuck the hose down into the sac and used a hose clamp over the bag threads. very small and short on top of the sac.