When you get bored......

[StirCrazy]

Originally Posted by shimmy

Im not trying to start any arguments over this, just making a comment.
Gate valves are not designed to be used as a throttling valve they are designed to be a 100% open or 100% closed, if you are looking for a valve that is designed to be throttling us a globe valve.

globes valves for this aplication are expensive as heck and not worth it. what we normaly get is ball valves which are horable for throttling, hence most of us use gate valves. In this aplication the gate valve works fine. If we were using a bronze gate then you are 100% corect as they tighten in there track as they close and having them 1/2 open they will chatter and destroy themselves, but the design of the normal gate valve we use is not this way and there for will not present a problem in this case and works very well for throttling.

As for ball valves they are horable and the worst valve you can use in this aplication for throttling as they have a non linear opening quality. I ended up pulling all the balls out of my system and throwing them in the garbage.


One thing I would add is I am against any valves on the return lines unless they are only for isolating for maintenance. throttling a return is just asking for trouble at some point. if you want to varry the flow between the sump and the fuge use line size to do it. if you want to varry flow through the system then throttle the pressure side of the pump.

Steve

[mark]

Originally Posted by StirCrazy

One thing I would add is I am against any valves on the return lines unless they are only for isolating for maintenance. throttling a return is just asking for trouble at some point. if you want to varry the flow between the sump and the fuge use line size to do it. if you want to varry flow through the system then throttle the pressure side of the pump.

Steve

See no problem valving the return on a Herbie (only) if the emergency drain is sufficently sized.

[StirCrazy]

Originally Posted by mark

See no problem valving the return on a Herbie (only) if the emergency drain is sufficently sized.

a herbie is different, it is the overflow not the return lines and requires adjustment to work, but it is only 1 out of the 3 lines that make up a good herbie that has a valve. what I am talking about is throttling the lines at the sump level, as in the drawing it looks like he will have a valve to restrict the flow into the fuge, and another at the sump. instead restrict the flow to the fuge by reducing the line size. so if you have a 1.5" return then after the dump into the sump reduce down to a 3/4" line if you want a lower flow to the fuge. another way is to make a spray bar in the fuge so your 1.5" line comes to a "T" say a 1.5 in 1" dual outs or 3/4 if you can find one, then get 4 to 6 more "t"s of the new line size so 1" or 3/4" pass through with a 1/2" tap and arange them across the one wall. this will give you a tone of flow through the fuge but it will be difused and even so it will be gental.

Steve

[Vancouver Reefer]

Ok so a change of plan. Im going away from the SQWD idea and will be using an OM of some sort. Either build my own or buy one. So i have 2 designs to pick from for tank layout:

Option1:
Rear overflow box, im concerned about the depth of the box not being enough and getting a gurgling sound from my herbie???



Option2:
Centre overflow:


Which one would you pick based on cost to manufacture, ease of maintenance and also asthetics ( My main concern!, I hate seeing equipment etc, even outside of the tank ).


Mr OM, the drawings are just for ideas and proposed layout, when i build im down to millimeters!! 5 Year engineering apprenticeship fundamentals drilled into me!!!! I cant be bothered to do a fully accurate CAD drawing for something i will be building. If it was for someone else to build, now thats a different story!!!

Any help would be much appreciated

VR

[Vancouver Reefer]

...................and you know i couldnt resist!!!!!

[golf nut]

If you are concerned about the herbie then do the overflow deeper, lose just 2 outlets from a 2 way at the bottom of the back of the tank, the upper 2 are doing nothing to help the flow anyway the way they are drawn, get the water to move from back to front at the bottom, fire the sump returns down the back glass, by doing this the surface water will move from front to back and get the best pre skim.

[Vancouver Reefer]

You mean like this:

[golf nut]

Yes, but even lower so you blow across the surface of the sand and get the detritus up into the water column. your returns from the sump will point down the back and effectively the whole tank will rotate backwards.

[Vancouver Reefer]

Ok so i get about lowering the returns from the OM and getting them to blow across the sand bed, but are you also suggesting i put elbows on and blow the return water directly at the bed??? That will stir up the bed every time the flow hits it???? Or am i missing something????

[golf nut]

What is the flow from the return pump?