diaphragm valve vs gate valve vs globe valve

[CEReefer]

I am planning the plumbing for a new build, it's a 4x2x2 tank, with 3 1-1/2" drains with a bean animal style overflow, and wanting to use a valve to control flow. Now I see that a lot of people here use gate valves, although all plumbing websites specify clearly that those should NOT be used for throttling operations, and a diaphragm or a globe valve should be used instead. Therefore I am debating between the diaphragm and the globe valve designs, if there is any plumbing expert out there, what would you install?

 

[X-37B]

I do not prefer to control the drain with any type of valve.
I use a ball valve on the return pump to control flow.
Been doing it that way 30+ years.

 

[CEReefer]

I do not prefer to control the drain with any type of valve.
I use a ball valve on the return pump to control flow.
Been doing it that way 30+ years.

Gotcha, I agree with you if this was a single drain system, but a drain valve is standard in a bean animal, also the 2 return pumps are DC, controlled by GHL flowmeters (one on each return), so they keep a stable flow, so no need to control the return with any valve in my case.

 

[monkeyCmonkeyDo]

That is exactly what they're telling u not to do. Put it on the intake of a pump. Throttling down the water it intakes.
Yes you can use it to control the water height level in your overflow. Yes you can use it on your outake of pump just like the other person does to control the gph outake of the pump.
It will put back pressure on the pump but ok as long as it's intake is 100%...
Basically... ball valves work. Gates are more precise and used for fine tuning such as on a bean animal style overflow.
Diaphragms and globe valves are gonna be used for closed loop systems. Which basically eliminate flow pumps from the display tank but will allow randomize flow patterns from the outputs using 2 or more outputs.
-d

 

[Sean Clark]

Yea you will get a lot of different perspectives on which way is "best" and how to implement them.
I use these.

 

[CEReefer]

That is exactly what they're telling u not to do. Put it on the intake of a pump. Throttling down the water it intakes.
Yes you can use it to control the water height level in your overflow. Yes you can use it on your outake of pump just like the other person does to control the gph outake of the pump.
It will put back pressure on the pump but ok as long as it's intake is 100%...
Basically... ball valves work. Gates are more precise and used for fine tuning such as on a bean animal style overflow.
Diaphragms and globe valves are gonna be used for closed loop systems. Which basically eliminate flow pumps from the display tank but will allow randomize flow patterns from the outputs using 2 or more outputs.
-d

Uhm... to be honest they all say gate valves are for on/off non-throttling operation ONLY, with no specification of intake vs drain, they do specify the issue is that when the flow is PARTIALLY restricted by the gate the valve gets eroded over time (although we may argue that usually people in this hobby quit well before we would see any of that, so that may not be a real problem).

some sources: 1) https://megadepot.com/resource/a-guide-to-types-of-valves#Gate Valves

2) https://www.mpofcinci.com/blog/flow-control-valve-types/#gate

 

[monkeyCmonkeyDo]

Yes. Non throttling. Idk what the confusion is. Lol.
D

 

[monkeyCmonkeyDo]

Most pumps will say not to limit the water intake... is this 1 of those gaslight threads? Lol.
D

 

[CEReefer]

Yea you will get a lot of different perspectives on which way is "best" and how to implement them.
I use these.

These are globe, right? Spears I am assuming? Why did you pick that over a diaphragm? Is georg fischer any good?

 

[CEReefer]

Yes. Non throttling. Idk what the confusion is. Lol.
D

Dude, it says ON/OFF NON-throttling it doesn't matter if you have a pump or not at one end, flow it's flow regardless of what generates it, period.

 

[Sean Clark]

These are globe, right? Spears I am assuming? Why did you pick that over a diaphragm? Is georg fischer any good?

Correct; Spears wye-pattern globe. I use these over diaphragm valves for their lower maintenance and ease of maintenance.
George Fischer is excellent quality but I have never used their valves.

 

[CEReefer]

Correct; Spears wye-pattern globe. I use these over diaphragm valves for their lower maintenance and ease of maintenance.
George Fischer is excellent quality but I have never used their valves.

Can you open them, for maintenance, like you would for a diaphragm one? Can you replace parts? the quotes I am getting are around 105$ for a globe like yours, and 160$ for a GF Diaphragm with true union on both ends (https://www.pvcfittingsonline.com/media/pdf_documents/514-data-sheet.pdf). In the end if that means I can maintain it and not have to rebuy it the extra 60 bucks are worth it.

 

[Sean Clark]

Can you open them, for maintenance, like you would for a diaphragm one? Can you replace parts? the quotes I am getting are around 105$ for a globe like yours, and 160$ for a GF Diaphragm with true union on both ends (https://www.pvcfittingsonline.com/media/pdf_documents/514-data-sheet.pdf). In the end if that means I can maintain it and not have to rebuy it the extra 60 bucks are worth it.

They completely disassemble without tools and you can replace every wear seal/part. Not that you should ever need to do so. I have been running the smaller one that I pictured since 2016.

 

[CEReefer]

They completely disassemble without tools and you can replace every wear seal/part. Not that you should ever need to do so. I have been running the smaller one that I pictured since 2016.

That’s pretty nice, from my understanding this has less maintenance than a diaphragm (i.e. the actual diaphragm may get eroded quicker than a globe valve), correct?

 

[Sean Clark]

That’s pretty nice, from my understanding this has less maintenance than a diaphragm (i.e. the actual diaphragm may get eroded quicker than a globe valve), correct?

My understanding is that it has to do with surface area. Both products with the same seal material and in the same environment will both deteriorate at the same rate. The higher exposed surface area of the diaphragm valve design can lead to additional degradation. The diaphragm valve needs more material to accomplish the same regulation. Not an expert. Just my understanding.

 

[CEReefer]

My understanding is that it has to do with surface area. Both products with the same seal material and in the same environment will both deteriorate at the same rate. The higher exposed surface area of the diaphragm valve design can lead to additional degradation. The diaphragm valve needs more material to accomplish the same regulation. Not an expert. Just my understanding.

Yeah, they are both made of EPDM so that makes sense, I need to do some more research if the ones with Viton (FKM) would last longer. All my other (ball) valves use FKM, but not sure they make these other valves with it.

 

[Sean Clark]

Yeah, they are both made of EPDM so that makes sense, I need to do some more research if the ones with Viton (FKM) would last longer. All my other (ball) valves use FKM, but not sure they make these other valves with it.

I have fkm and epdm and I will say that the fkm is a bit harder (more dense) and is less forgiving to any angular pressure.
I always search and buy what is available and cheaper. You can often find the Viton part cheaper than the EPDM.

What are you looking for specifically? I have a lot of free valves looking for good homes if you are in the states.

 

[CEReefer]

I have fkm and epdm and I will say that the fkm is a bit harder (more dense) and is less forgiving to any angular pressure.
I always search and buy what is available and cheaper. You can often find the Viton part cheaper than the EPDM.

What are you looking for specifically? I have a lot of free valves looking for good homes if you are in the states.

Yeah, I was reading about it, FKM it’s more abrasion resistant than EPDM. Let’s say that for our purpose (saltwater) EPDM is more than enough. Thank you for the offer, I am in Ohio, but I already have the ball valves, I went with cepex (not from the overpriced BRS), hopefully they are decent.. Hayward was the other option but they were 10$ more each (I have 12 in my system) and actually had worse flow factor (Cv)