Is a gate valve needed if using a DC return pump?

[TatorTaco]

If the return pump's flow rate is adjustable, wouldn't the gate valve be redundant?

My thinking is that the the gate valve can restrict flow created by the return pump. If you can adjust the flow on the return pump, the gate valve is no longer necessary.

 

[PopBot16]

If the return pump's flow rate is adjustable, wouldn't the gate valve be redundant?

My thinking is that the the gate valve can restrict flow created by the return pump. If you can adjust the flow on the return pump, the gate valve is no longer necessary.

Correct, not needed. TBH, gating it back that way will reduce the lifespan of the pump anyway due to back pressure.

 

[BryanM]

My understanding is that while not necessary it is desirable to fine tune flow. I can only guess that this is a thing because most dc return pumps can't be fine tuned enough to get it "just right".

 

[bradreef]

I say, not necessary. I run 2 dc returns on a ball valve, I adjust height with the pumps.

 

[Troylee]

Should only need it on your drain pipe regardless if the return pump is variable speed or not.

 

[JayM]

It s not needed, but I have a ball valve on my return. It’s only there to keep tank water from draining into the sump on the rare occasion that I pull the pump for maintenance.

 

[C_AWOL]

On the return no valves are needed unless you have a reason to make directional adjustments like a manifold or you want another shut off point for maintenance (can save money with a ball valve/union ball valve)

Definitely still recommend a gate valve if using 2+ drains though

 

[TatorTaco]

On the return no valves are needed unless you have a reason to make directional adjustments like a manifold or you want another shut off point for maintenance (can save money with a ball valve/union ball valve)

Definitely still recommend a gate valve if using 2+ drains though

I'll have a normal drain and emergency drain. If the return pump's flow is variable, I wouldn't need a valve to regulate how much flow goes through the drain. Right?

 

[Troylee]

I'll have a normal drain and emergency drain. If the return pump's flow is variable, I wouldn't need a valve to regulate how much flow goes through the drain. Right?

If you get lucky no! But I’d say yes if you want it super quiet! I run all my tanks with a full siphon and there’s no way around a valve to fine tune it! If you’re running a durso with an air gap and don’t mind some noise or bubbles then you’d be okay.

 

[TatorTaco]

If you get lucky no! But I’d say yes if you want it super quiet! I run all my tanks with a full siphon and there’s no way around a valve to fine tune it! If you’re running a durso with an air gap and don’t mind some noise or bubbles then you’d be okay.

Makes sense. I already have the gate valve, and I planned on getting a DC pump anyway, so I'll just run both.

At least now I'm aware that it's an option, and I can utilize both to increase or decrease the flow that comes through my sump. In my current setup, I thought the Gate Valve's ONLY purpose was to silence the noise. Now I understand the "why" behind it.

 

[C_AWOL]

I'll have a normal drain and emergency drain. If the return pump's flow is variable, I wouldn't need a valve to regulate how much flow goes through the drain. Right?

The gate valve on the drain is to adjust the drain flow to prevent/eliminate any air going into the drain (primary source of noise)

 

[TatorTaco]

The gate valve on the drain is to adjust the drain flow to prevent/eliminate any air going into the drain (primary source of noise)

I agree, but my question was if you can accomplish the same result via a DC pump.

 

[KStatefan]

I agree, but my question was if you can accomplish the same result via a DC pump.

Are you talking about a gate valve on your return or your drain? If you are talking about the drain yes you need something to control the flow of the siphon drain.

 

[John Neuzil]

that will not reduce the life a magnetic driven pump

 

[John Neuzil]

Possible but more difficult to fine tune.

 

[Featherweight]

Gate valve to fine tune main drain. Any other valve where you may like to clean or service. Valves are not just for dialing back return flow... There's many reasons

 

[twentyleagues]

I have the same type of set up. Using only the controllable output of the pump the drain still "surged". IMO the valve is needed for smoother operation. Maybe its my pump of choice maybe not. I have no way to tell what the power level displayed on the controller actually translates to in gph is it 10, 50, 100gph? What if I need 33gph to make it work right? Valve is the answer.

 

[Shirak]

I agree, but my question was if you can accomplish the same result via a DC pump.

No because your drains should handle much more water flow than your return pump can push to the tank. So you need the gate valve on the main drain. The return pump should push enough water through the tank so you get roughly 5X tank turnover per hour through the sump. Too little and your filtration will likely be insufficient. Too much and it will be a raging river through your sump.

 

[Justdrew]

I agree, but my question was if you can accomplish the same result via a DC pump.

I'd say no. It would take an extreme amount of flow to fill the main drain and not have it make any noise. That is the primary goal of a gate valve on the main drain. Slow it down enough to prevent "slurping"

 

[BeanAnimal]

Correct, not needed. TBH, gating it back that way will reduce the lifespan of the pump anyway due to back pressure.

That’s absolutely not true.


Valving back the output of a centrifugal pump (i.e., increasing static head) does no harm to the pump. It can even be fully dead-headed without damage -- aside from potential overheating due to lack of flow to dissipate heat.

Increasing head doesn't increase pressure in the pump; it simply moves the operating point left on the curve. The pump actually does less work because it moves less water. In fact, it's often operating closer to its best efficiency point (BEP) when slightly valved back, rather than running wide open.

At BEP - the pump is moving the most water per watt consumed -- thus running cooler and typically with less vibration or noise.

This is fluid dynamics 101 :)