Gate vs quarter turn valve.

seized123

At the risk of seeming totally nitpicky, would the quarter turn valve be better longevity wise than the gate valve this boiler came with? Thought I’d ask while I have an empty boiler and switching would be easy.

Mad Dog_2

Exercising ANY valve is the key to longevity. Mad Dog

seized123

Good point. I’m just worried about it freezing up. Some other gate valves in this house have but I never exercised them.

delcrossv

Ball valves seem to be less prone to locking up.

Jamie Hall

Ball valves are, I think, a little more forgiving in terms of lack of operation and water quality — and, perhaps, orientation.

They also do one thing that gates cannot do: be set partly open. Yes, before you scream, a gate can be set partly open too — but it isn't good for it to stay that way. Either open or closed, thank you. Ball valves aren't all that good at throttling flow — they are very non-linear — but at least they can do it without damage.

Gates are also more sensitive to water quality, and if they are used where there is significant solid material and they are oriented stem up (the usual), they can fail to close properly.

In larger or high pressure applications, they must reflect pressure direction: when they are closed the high pressure must be such that it presses the gate against the face when closed.

On the other hand, if maintained, they will never seize up, or at least I've never seen that happen (if the stem is not kept slightly oiled, yes but not otherwise) whereas ball valves can sometimes.

Which makes it sound like ball valves are the way to go. But not always. In larger sizes they can be remarkably difficult to operate; gates are less sensitive to that. In very large sizes ball valves can also be very expensive, and have a longer laying length than gates. Ball valves also sometimes have trouble with the seals for the ball; gate valves depend on the accurate machining of the gate and the face and that isn't a factor.

In general, though, for smaller valves I'd go with ball valves.

EBEBRATT-Ed

Nothing wrong with a gate valve except……..the cheap ones will leak every time.

A cheap ball valve will outlast a cheap gate valve. And ball valves generally don't leak except the cheapies will leak around the stem.

Jamie Hall

True, @EBEBRATT-Ed . a cheap gate valve often won't close fully off. A properly machined one won't — but that removes them from the cheap category!

hot_rod

what is the gate valve being used to shut or regulate?

seized123

@hot_rod just the drain on new a boiler. Comes with a gate valve, but I have a ball valve on hand so it’d be easy to switch while the boiler is empty. Also I plan to switch out five old gate valves on zone piping to these new ball valves.

leonz

Keep in mind that over time a ball valve will leak through the stem. You can always repack the stem on a gate valve which is something you cannot do with a ball valve.

seized123

@leonz I’m guessing you have to remove a gate valve to repack it, or at least have the water drained from where the valve is?

Mad Dog_2

No..A Gate Valve is repacked via the bonnet. Mad Dog

Mad Dog_2

If exercised regularly, I have seen Gate Valves that are 100 years old hold. The Jury is out on ball valve longevity vis-a-vis gate Valves, but high quality American Made Ball Valves like Apollo, Nibco, Hammond, et cetera are now over 60 yrs in operation. Mad Dog

Revenant

I have fixed several stem leaks by wire brushing the stem. Then cycle the valve and loosen and re tighten the bonnet to redistribute the existing packing. Repeat a couple of times.

If that doesn't work , then repack.

Once that didn't work, so I bought a new valve and put the new guts in the old valve body.

I'll do almost anything to avoid sweating copper.

On seldom used valves, I like to loosen the bonnet before I close the valve.

delcrossv

Mechanics mate on a submarine told me when leaving a gate valve open, always back it off a little, like 1/8 turn from the stop. Keeps the valve from freezing open.

hot_rod

how often do you plan on draining the boiler?

Maybe a rubber washer compression stop is best , like you used to see on water heaters, worse case you screw a cap on it if it drips. The stems rarely freeze on that type of valve

mattmia2

Gate valves can to some extent lap themselves to clean the gate off. ball valves if they scale, the scale is unlikely to come off the ball. many ball valves have a packing on the stem that can be repaired.

seized123

@Mad Dog_2 and others, is Watts a good brand? I bought five of these from Supplyhouse:

https://www.supplyhouse.com/Watts-0820956-3-4-Quarter-Turn-Boiler-Drain-Drain-Cock

to replace these in photo below (just the drains, not the shut-offs, but they’re NIBCO)

for no better reason than they’re probably 30 years old and I heard from who knows where that ball valves are better. They’re on the zone returns and will obviously hardly ever be open. I can return the new ones, but it sounds like the jury’s out. Hey, you mentioned Nibco as American made. Didn’t know that. I try to get Apollo ball valves but sometimes just the cheaper imported ones, but if possible sometimes spring for the Made in USA’s if available.

delcrossv

Watts is fine.

leonz

Whyt change them if they are not leaking??

seized123

@leonz great question. A tech with a lot of experience who came to assess my leaking boiler just threw that out there about putting in quarter turns along with other helpful advice about DIYing the replacement boiler so I just ordered them when I ordered all the other parts. Trigger happy, I guess. You’re right, they’re not leaking, and from this thread it looks like there’s no clear advantage either way and from what I understand I could repack if necessary without draining the system so why pay $88 for something I don’t need. I’ll probably return them to Supplyhouse and pay shipping and feel stupid for only about 5 minutes.

mattmia2

globe valves are great for boiler drains, easy to repair with standard parts

seized123

@mattmia2 I assume (without reason, actually) that what I have there are gate valves, not globe valves?

mattmia2

Does the stem rise when you open and close them? I think that is a globe valve where the stem just screws straight in and the seat is at the end where the connection is. You can look in the hose connection with a light to see what type of valve it is.

In that application i would just use an npt valve then you can easily replace it if it fails.