Shower Valve Opinions

[Phog]

Hello all, going to redo the shower soon and looking for some input on valves to aid in my selection process. Looking for a basic pressure balancing valve, but definitely needs flow control capability (ie. Moentrol would be a "yes", Posi-temp "no"). This will be for a shower only-- no tub spout. What say you out there, master plumbers? I'd like to choose something that has a large selection of trim kits available if possible, and works simply & reliably for your customers. Nothing fancy needed. Oh, and last, I don't want any gotchas when i need to replace the cartridge someday. Ie. please not something easy to break like the Delta 600 Series I dealt with last year. Thanks in advance.

 

[Terry]

The Delta 600 was a difficult valve to do repairs on for sure.
The new Delta valves have been working well. Any of those that come with volume control should be good, and the Moentrol has been out for years. That's also good.

 

[Sponsor]

 

[Phog]

Thanks Terry. The Delta Multichoice (R-10000) seems to have more trim kits available than the Moentrol so I'll probably go with that. In choosing a valve body I see there are lots of options - connection type, with stops vs without stops, etc. I understand everything except for the valves with "HF" in the P/N (for High Flow). What would a "high flow" type valve be needed for -- filling tub faster? I can't see how that would be needed for a shower but want to make sure I'm not limiting my future options by choosing the wrong valve body.

 

[Jadnashua]

Some people prefer human car washes...i.e., multiple heads, sprays, etc., all running at the same time. THere, to ensure you get the full benefit, you need high flow. It can also be useful to fill a big tub faster. A typical 1/2" valve is often rated at 5-6gpm. Given a big soaker tub might contain 60-gallons or more, speeding up the fill rate can be useful as when you have 3-4 body sprays at 1.5gpm and a main showerhead, that could be nearly 10gpm...beyond the capacity of a 1/2" valve to function. Then, you need to consider the maximum velocity recommended by the tubing manufacturer you have. 1/2" copper is rated by the Copper Institute for no more than 4gpm on the hot side, and 3/4" at 8gpm. Depending on how hot your water is, and how cold your cold supply is, you may never achieve the full capability of your shower system if you have multiple sprays. A few issues with asking the piping to exceed the design flow velocity:
- decreased dynamic pressure (i.e., higher pressure drop)
- potential internal wear on the tubing
- flow noises

Note, most thermostatically controlled valves from the same manufacturer will flow more than their other designs. On many of them, they let full hot through, and temper it with the cold. A typical pressure-balanced valve starts off with mostly cold and then blends in more and more hot as you go towards the stop, resulting in a lower maximum volume through it.

 

[Phog]

Note, most thermostatically controlled valves from the same manufacturer will flow more than their other designs. On many of them, they let full hot through, and temper it with the cold. A typical pressure-balanced valve starts off with mostly cold and then blends in more and more hot as you go towards the stop, resulting in a lower maximum volume through it.

Thanks, that's helpful. It sounds like you're referring here to valves without volume control. Or am I misunderstanding?

 

[Jadnashua]

I put a thread in the tutorial section on the different types of tub/shower valves that might help.

A thermostatically controlled valve typically has two knobs/levers...one for on/off/volume and a second one for temperature setting. All of the others (well, there are two) start off cold, and you then change the balance between the hot and cold, often, never getting full volume on hot or cold.