When you get bored......

[elitesurfer]

That looks so realistic and your journal website is too good. Props to you!!

[Froggie]

Originally Posted by shimmy

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.
Now I am new to SW fish tanks but I do have a good idea of affects of flow through valves and I do know that when you use a gate valve you with wash out the seat on the valve then it becomes very difficult or impossible to get isolation.

I'd say you're absolutely correct in your comment regarding gate valves.
I think that one of the reasons that the hobby has taken to using them for this application is that small diameter CPVC globe valves are a specialty item. They're high cost and generally unavailable (IPEX doesn't even list them on their website). The same can be said for butterflys and they've some additional real estate requirements.

In all actuality ball valves have better throttling characteristics than gates... but try fine tuning a stiff plastic quarter turn ball valve.

[shimmy]

Originally Posted by Froggie

I'd say you're absolutely correct in your comment regarding gate valves.
I think that one of the reasons that the hobby has taken to using them for this application is that small diameter CPVC globe valves are a specialty item. They're high cost and generally unavailable (IPEX doesn't even list them on their website). The same can be said for butterflys and they've some additional real estate requirements.

In all actuality ball valves have better throttling characteristics than gates... but try fine tuning a stiff plastic quarter turn ball valve.

Yes glob vales are a special item to be found but not impossible and not cheap. I just personally know that nothing can make your day feel like the worst you ever had when you cant isolate a pump because a decision that was easier at the time.
For cost I would recommend the ball valves and put the extra time in to set them just perfect.
By no means im I saying its wrong or cant be done to use gate valves to throttle, but with that said I feel little remorse for people that take the easier at the time approach to projects that should have a little more energy put into them.

[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: