Compression vs. Quarter-Turn Shutoff Valves

Learn the differences between and pros & cons of compression and 1/4 turn stop valves

Control is a wonderful thing to have. Not in the tyrannical, totalitarian sense, of course. But in the day-to-day sense, control over the minor things in life goes a long way in maintaining sanity. One of the quickest ways to lose that sanity is a plumbing emergency like a flood. And for the unhandy, even a "simple" plumbing repair can leave a scene of comparable horror. Here, control takes the form of a well-maintained (and designed!) plumbing system. Design features and special devices that make it easier to control a home's water supply - as well as eliminate or mitigate potential disasters lying in wait - are part of most home's plumbing systems. One of the simplest and most important is the shut-off valve (or "stop"), which does exactly what the name implies.

The shut-offs for the whole house and the water meter are clearly the most vital, so be sure to know where they are. Thing is, that location is almost always outside the house, usually a good distance from where the action is. There are times when there's no time to go all the way to the main shut-off, times when it's unnecessary to turn off water to the whole house, and times when it's simply inconvenient. This is why they make shut-off valves for individual fixtures, and why it's important to have quality ones installed.

Shut offs at fixtures are required by many building codes, and have become standard given their effectiveness and convenience. Take a look behind your toilet or under a sink, and you'll likely see one of two valve types: a "compression" valve (not to be confused with the compression fitting connection type, where a nut and sleeve are used to create a seal) or a quarter-turn valve. Both do the same thing, making it much easier to perform repairs and replace fixtures. They can also help keep your bathroom or kitchen from requiring FEMA assistance.


How They Work

Compression valves, also known as multi-turn valves, are usually globe valves. They feature a stem with a rubber washer on the end, which is attached to the valve handle. When turned, the stem moves into the cavity of the valve, compressing the washer against the internal seat and forming a seal.

Quarter-turn valves are a more recent addition to the plumbing arsenal, and employ a ball valve design. A turn of just 90 degrees orients the hollowed-out ball inside to either block the water's path, or allow full flow through the unit.


Pros & Cons

So, which design is better? As with most plumbing questions, it depends on who you ask. Some folks like that multi-turn shut-offs can be repaired. When a compression washer is kaput due to water degradation, it can be replaced, as can the packing in the valve (which helps to prevent leaks around the stem). Sometimes, the fix is even easier: some leaks can be stopped by simply tightening the valve's packing nut.

While tightening the nut is simple enough, further repair to a multi-turn valve may not be worth it. Replacing the entire valve doesn't cost much more, and safeguards against the possibility that worn parts still remain after the repair, which could lead to problems. In addition, parts for older valves may be hard to track down.

When a quarter-turn shut-off starts leaking, it must be replaced. Quarter-turns typically cost a dollar or so more than other valves, but it's unlikely that this will make a substantial difference in the final bill (unless you're outfitting a mansion, or high-rise). More of a concern is the potential for water hammer when using these valves, since they can be closed so rapidly – multi-turn valves can't help but close slowly.

Quarter-turn valves shine in other ways, though. Their relatively simple construction reduces the points of wear, which – best case scenario - results in a more durable, longer-lasting valve. Construction material, build quality, and other factors can work against this, however, and potentially negate any increased durability. Be sure that the quarter-turn shut-offs you buy are high-quality ones: the ball inside should be metal, not plastic. (The quarter-turn shut-offs we offer feature all-metal construction.)

However long the valve lasts, it should be easy to use. Because they only need to turn a fraction of the distance of a compression valve, both the effort and space required for quarter-turn operation is reduced, much to the benefit of the elderly and those living with arthritis and other conditions. Quarter-turns are also easy to "read" - because the handle is only partially turned, a quick glance at its position tells you whether the valve is opened or closed.

Shut-offs in general have a reputation for not working when you need them. Either the stem or handle will seize up, preventing any movement, or the stem will simply break off (a point to multi-turn valves: they can sometimes be "worked out" when seized; quarter-turn valves cannot). Whether this is actually a regular occurrence or a common exaggeration is for the plumbers to decide. Countless factors influence the performance of a piece of hardware, and when water enters the picture, things get even more complicated.

The best that can be done to prevent these failures is to purchase well-made parts (not the cheapest you can find) and be certain that installation is done correctly. Leave the valves fully open, and don't over-tighten when the time comes. It's also not a bad idea to test your shut-offs once in a while and replace them as needed, outside the pressure of an emergency situation. Most importantly, be sure to know where your main shut-off is: if the valve at the fixture fails, you'll have precious little time to run to it and prevent serious water damage (better yet, have someone at the ready). And if that valve fails, you always have the water meter shut-off. And if that valve fails... actually, no, let's not think about that.

So again, which design is better? Most will say quarter-turn for build quality and ease of use. Some will stick with multi-turn compression valves because they're used to them, and trust them. Chances are that whatever you choose, it will work fine for years.



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