Plumping new tank question

[vhoang2]

So I have 3 internal overflow holes in the 120G tank. 1 of them size 1 1/2 and 2 others 3/4. I have planned to do a "herbie" style, so the 1 1/2 will be main drain (*) and one of the 3/4 is emergency drain. The remaining 3/4 is used for return of course.

Now the problem is, since I could not find a gate valve for 1 1/2, I ended up getting an 1 inch and plan on reducing the main drain (*) from 1 1/2 to 1 inch. So basically I will have the main drain at 1 inch and return is 3/4 inch. I guess the other emergency drain is not to be counted as it does not always drain anything unless, an emergency.

Question - any problem with this and/or any recommendation?

Thanks

 

[mdb_talon]

I would personally not limit the size of drain to sump. With an appropriately sized return pump it will work, but reduces the turnover you could handle if using full size drain.

I use gate valves on the drain, but really see very little actual purpose for them would much sooner skip the gate valve than reduce drain size.

 

[KStatefan]

So I have 3 internal overflow holes in the 120G tank. 1 of them size 1 1/2 and 2 others 3/4. I have planned to do a "herbie" style, so the 1 1/2 will be main drain (*) and one of the 3/4 is emergency drain. The remaining 3/4 is used for return of course.

Now the problem is, since I could not find a gate valve for 1 1/2, I ended up getting an 1 inch and plan on reducing the main drain (*) from 1 1/2 to 1 inch. So basically I will have the main drain at 1 inch and return is 3/4 inch. I guess the other emergency drain is not to be counted as it does not always drain anything unless, an emergency.

Question - any problem with this and/or any recommendation?

Thanks

BRS has the 1 1/2 gate valve in slip and FPT

 

[vhoang2]

I would personally not limit the size of drain to sump. With an appropriately sized return pump it will work, but reduces the turnover you could handle if using full size drain.

I use gate valves on the drain, but really see very little actual purpose for them would much sooner skip the gate valve than reduce drain size.

I thought the gate valve is to 1-fine tune the flow and 2-in case of emergency you can stop draining.

I do get your point, but my question is if I reduced the drain from 1 1/2 -> 1, any ill effect?

 

[mdb_talon]

I thought the gate valve is to 1-fine tune the flow and 2-in case of emergency you can stop draining.

I do get your point, but my question is if I reduced the drain from 1 1/2 -> 1, any ill effect?

Never adjust flow rate to sump using a gate valve. Flow to sump should/will match the flow of return pump. If return pump is 1000gph then the drain needs to handle 1000gph. Tweaking a gate valve so it is 950 just means you get a wet floor. Adjusting it to 1050 makes zero difference.

Again the negative is you are limiting your max turnover and size of return pump you can use.

 

[KStatefan]

I thought the gate valve is to 1-fine tune the flow and 2-in case of emergency you can stop draining.

I do get your point, but my question is if I reduced the drain from 1 1/2 -> 1, any ill effect?

It will reduce the max flow rate that your main can flow when wide open. In my opion I woud swtch to the 3/4 for your main drain and use the 1 1/2 as the emergency. When your emergency is smaller than your main it really is not an emegency

 

[vhoang2]

Never adjust flow rate to sump using a gate valve. Flow to sump should/will match the flow of return pump. If return pump is 1000gph then the drain needs to handle 1000gph. Tweaking a gate valve so it is 950 just means you get a wet floor. Adjusting it to 1050 makes zero difference.

Again the negative is you are limiting your max turnover and size of return pump you can use.

I have seen every major company, Red Sea, Waterbox, IM put a gate valve on the main drain. I wonder why they put it there then?

OK - I will see if I could get the 1 1/2 equipment. Thanks.

 

[mdb_talon]

I have seen every major company, Red Sea, Waterbox, IM put a gate valve on the main drain. I wonder why they put it there then?

OK - I will see if I could get the 1 1/2 equipment. Thanks.

Most people use gate or ball valves on drain(i do also) so it dont surprise me you see it from major companies. I am just saying their usefullness is extremely limited and given an option i would forgo a gate valve before i limited my drain capacity.

I think the most useful aspect of gate valves on drain lines is when you are diverting part of water flow(ie refugium, scrubber,etc). Can set it up so you limit flow to specific areas, but dont want to limit overall drain capacity.

Can also be used in an emergency scenario if you have a bad seem between the DT and standard overflow for example). Even in thst scenario if using a standpipe of appropriate height it probably wont matter. I am sure there are other rare scenarios is may be useful, but just saying in all likelihood you wont use it....and if you do it should not be for regulating flow to the sump(unless using multiple drain lines).

 

[vhoang2]

Understood and thanks again for your help. I've ordered the 1 1/2 equipment now. I guess the sizing were already there for a reason.

 

[Bruce60]

I only have a ball valve on my drain. This allows me to turn it off if I need to work on the plumbing.

 

[vhoang2]

It will reduce the max flow rate that your main can flow when wide open. In my opion I woud swtch to the 3/4 for your main drain and use the 1 1/2 as the emergency. When your emergency is smaller than your main it really is not an emegency

Forgot to respond - I have not seen anyone advising to switch to smaller main drain in this case it would match the return size which I have seen advised against. Also I think emergency here is really when water keep raising above the threshold level. In a herbie the emergency is higher than the main drain as far as I see. Pls let me know if I’m mistaken.