Quick Plumbing Q

[phenom5]

I'm getting ready plumb my new tank, and I'll probably go and pick up the supplies this weekend.

This is going to be a pretty straight forward, simple plumbing set up (famous last words). I notice a lot of people put valves (ball, gate, true-union) in their plumbing. I was planning on putting in unions, but no valves.

Any particular reason for using valves?

[der_wille_zur_macht]

You'll pretty much NEED the valves if you're going to use unions. The valves are there to stop the flow of water and seal off the part of the plumbing you'll be removing (with the unions.) Otherwise, if you want to disassemble your plumbing, you'll have to drain a significant portion of the water from your system.

Imagine this - you have an external sump return pump sitting next to your sump. Between them, you have a ball valve followed by a union. If you want to remove the pump for service, you turn it off, shut the ball valve, and disassemble the union. Without the ball valve, you'd have to drain the sump before disassembling the union, otherwise the sump would simply drain out the open plumbing.

[Wilberheim]

In addition to that you may need one after your return pump to throttle back the flow to match what your drains are well draining.

[phenom5]

You'll pretty much NEED the valves if you're going to use unions. The valves are there to stop the flow of water and seal off the part of the plumbing you'll be removing (with the unions.) Otherwise, if you want to disassemble your plumbing, you'll have to drain a significant portion of the water from your system.

Imagine this - you have an external sump return pump sitting next to your sump. Between them, you have a ball valve followed by a union. If you want to remove the pump for service, you turn it off, shut the ball valve, and disassemble the union. Without the ball valve, you'd have to drain the sump before disassembling the union, otherwise the sump would simply drain out the open plumbing.

Sorry, should have clarified. I'm not talking about an obvious situation like an external return pump.

I've been looking at a lot of plumbing threads, and people put valves on their drains, or their returns with submersible pumps. Obviously, If you've got a complex manifold, or an external pump, you need the valves.

I've got a submersible return pump. Simple drain, simple return. Just curious if I was missing something, and there was a reason for the valves. Unions at the bulkheads, and the pump.

[Chris27]

It's generally a very bad idea to put a ball valve on the drain. A person may have the best memory in the world, but at some point in time they will forget to open it back up and then they will have water spew out of the DT and onto the floor.

As for a ball valve on the return, it's not necessary if you choose the proper return pump, ie. a mag 9.5 on a 75 Gal reef ready works fine, but if you throw a Mag 18 on there you'll need to tone it down a bit - thus a ball valve.

I only use unions when I absolutely have to - again - something else that can fail and put some more water from the DT to the floor.

You thinking is correct, you're not missing anything, it's really that simple - no sense in over-engineering it.

[der_wille_zur_macht]

It's generally a very bad idea to put a ball valve on the drain. A person may have the best memory in the world, but at some point in time they will forget to open it back up and then they will have water spew out of the DT and onto the floor.


We are getting in to semantics here, but IMHO it's important to point out that ball valves may be on drain lines for a number of different purposes - some of them totally valid, others risky and probably not worthwhile. IMHO it's especially important to be explicit about this in this thread given the OP's questions about "seeing lots of ball valves on designs."

For instance, on a bean-style drain system, the valve on the siphon line is a REQUIREMENT of the design. It's not there to shut off the flow for maintenance, it's there to allow for the adjustment inherently required in the design. Given that, it's totally valid and needs to be there.

Meanwhile, other people slap a ball valve on a regular old Durso-style drain system - in that case, yeah, your argument makes a lot of sense, and the valve is more or less superfluous.

[phenom5]

It's generally a very bad idea to put a ball valve on the drain. A person may have the best memory in the world, but at some point in time they will forget to open it back up and then they will have water spew out of the DT and onto the floor.


Valves on drains do have a place, as der_wille_zur_macht mentioned in Bean's failsafe overflow design as an example.


As for a ball valve on the return, it's not necessary if you choose the proper return pump, ie. a mag 9.5 on a 75 Gal reef ready works fine, but if you throw a Mag 18 on there you'll need to tone it down a bit - thus a ball valve.

As far as throttling down returns, sure, that's a reason. I personally prefer redirecting water back to the sump, but that still requires...you guessed it, some sort of valve.

I only use unions when I absolutely have to - again - something else that can fail and put some more water from the DT to the floor.

Unions are sort of a must. IMO you have to have some way to remove your plumbing. I plan on putting a union at each bulkhead, and at the return pump.

You thinking is correct, you're not missing anything, it's really that simple - no sense in over-engineering it.

Thanks, that's what I was thinking, but I just wanted to double check. Like I said, wanted to make sure I wasn't missing something.

IMHO it's especially important to be explicit about this in this thread given the OP's questions about "seeing lots of ball valves on designs."

Probably wasn't the best to make a broad, sweeping statement like that.



Meanwhile, other people slap a ball valve on a regular old Durso-style drain system - in that case, yeah, your argument makes a lot of sense, and the valve is more or less superfluous.

Basically that's what I was asking about. Maybe there was more going on than what I could tell with some of the pictures that I was saw...but looking at some plumbing pictures it seemed like there was an excessive use of valves. So I wanted to make sure there wasn't something that I was missing (wouldn't be the first time).

Thanks for the input.