globe valve. not gate, not ball.

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by geniescience, Sep 4, 2007.

  1. am wondering about globe valves, but can't find much about them.

    Why are they suited to variable flow situations? How do they work?
    Do they make less noise when they are partially shut / partially open?

    David
  2. Furd

    Furd Engineer

    Messages:
    446
    Location:
    Wet side of Washington State
    [​IMG] This is a rising stem, bolted bonnet globe valve.

    [​IMG] This is a screwed bonnet globe valve.

    [​IMG] This is a union bonnet globe valve.

    Notice that in all cases the flow is from under the disc/seat to above the disc/seat. In all but the least expensive globe valves the disc is readily replaceable as it wears, the proverbial faucet washer. Better valves also have replaceable seats although it usually requires a special wrench to remove and replace them.

    The bolted bonnet is the strongest construction although the union bonnet is often used in smaller sizes. The screwed bonnet design is the weakest and most often used in residential plumbing because of its low cost.

    This is a bolted bonnet rising stem gate valve. [​IMG]

    This is a common screwed bonnet gate valve such as one would see in residential service. [​IMG]

    Notice that the gate valve has a straight flow through it when wide open vs. the globe valve that must make two ninety degree turns. Notice also that if the gate valve is only partially open the the "gate" is directly in the flow and subject to erosion by the passing fluid. Since the erosion of the "gate" will destroy the closely machined fit of the gate to the side-facing seats the gate valve is not a preferred choice for throttling applications. Furthermore, the gate is relatively loose in the "guides" that control its motion when the handwheel is turned and under certain circumstances it will vibrate in the flow and wear the guides.

    Does that help?
  3. kordts

    kordts In the Trades

    Messages:
    551
    Location:
    exurban Chicago
    Globe valves are only needed when you want to throttle the flow, like in industrial plants. For commercial and residential, ball valves are the best.
  4. one guy says globes are good for washer connections in residential. A young plumber who got his Master Plumber status this year. One day I'll figure out why he thinks that.

    I was hoping globe valves might be a solution to regulate flow. Some problems with excess flow are water hammer with ON-OFF switches like DW and washing machines, noise, and splashing.

    Mostly, noise.

    Personally I like low-noise plumbing. If water flows without whistling, hissing, rushing, whizzing, without making any noise that I could ever hear on a quiet weekend morning, I like it. I like those little bar taps they sell for less than $30.

    I have put two ball valves in series just to lower the noise level they each make when used halfway. This reduces flow while making less of that turbulent noise, since each ball valve is doing half the work...

    A hand rinse sink doesn't need the amount of water that 1/2" copper can carry, but instead of reducing to 3/8" or 1/4" copper, I added a ball valve before the angle stop at the flex connector, so as to make each valve do about half the work of cutting flow. Now there is quiet in my bedroom when somebody uses the water at that bathroom sink. Also, when someone turns on the tap all the way, the amount of water is properly adjusted to prevent a lot of back splashing from happening. Open the pipe up all the way, and the experience at the tap is not as pleasant. I can't rely on the faucet's hand lever to do all the work; there is just too much flow blasting out, even with an aerator.

    A toilet refill can make a lot of noise. I added a ball valve before the angle stop there too for the same reason. The flow noise is reduced. The toilet tank has enough water for two flushes so I am not concerned about the length of time needed to refill it. Before, when I used the single angle stop to reduce the flow, I ended up with a valve making a lot of noise during refill.

    I can see why people like CPVC pipe. Everyone says it is quiet. I must use copper because my building is a highrise (condo apartments). In a concrete structure, background noises are very low. I even have concrete walls, so I never hear the elevator noise. Plumbing noise sounds that much stronger, compared to the quiet environment. In another structure, the problem is not present. A townhouse condo does not have this problem since it is mostly wood structure and it is open to the elements on more sides. Wind and weather make a fair amount of background hum; water flow noises appear less significant. I gave an old computer to a friend in a townhouse condo and the computer made a very acceptable normal fan noise over there at his place. The reason I got rid of it is because of the noise in my place. Especially after I got rid of carpeting and put in tile.

    When a dishwasher pulls water through copper pipe, the water flow makes noise. Put that DW in a concrete building and the noise is more audible than it would be in a wood frame building. Put that DW in an open kitchen, an open space, or in a kitchen that has no doors, and the flow in the pipes is a part of the noise you live with whenever you use the DW. Buy a $1000 DW that makes little noise and you have not solved the problem -- you have made it slightly worse since the pipes are now the biggest noise heard.

    The pipe is the noise.

    Since there are millions more concrete condo dwellers than ten years ago, you will hear more and more queries about how to get quiet or silent plumbing, in the next ten years.


    David
    p.s. To get a silent computer, get an Imac. The other manufacturers never discuss their noise level.
  5. Furd

    Furd Engineer

    Messages:
    446
    Location:
    Wet side of Washington State
    Noise comes from high velocity. Larger pipes allow the same flow with lower velocities so generally speaking larger pipes will be quieter than smaller pipes. For most residential services 1/2 inch pipe at the fixture gives decent flow and quiet operation.

    If you have excessive, I know that is a subjective term, noise from your plumbing then I would suggest that you investigate the static pressure and dynamic pressures at various outlets.

    Valves, of any type, because they have a tendency to restrict flows can either increase or decrease the noise of the plumbing system. Using a gate or ball valve to restrict flow WILL cause the valve to wear. This is not as noticeable with a ball valve because the stainless steel ball is much harder than the brass or bronze gate of a gate valve. Throttling with a brass or bronze gate valve will destroy the ability of the valve to close tightly quite rapidly.

    The globe valve, because of its much greater restriction, is inherently noisy yet in the proper application the noise factor is usually not excessive.

    It was probably not necessary to have the ball valve and angle stop in series on your toilet supply. Using an ordinary (not quarter-turn) angle stop you would have a globe valve and you could have throttled that valve to limit the flow to the toilet without problem. One thing that I found in regard to toilets is that the fill valve usually has a fairly small orifice and if there is dirt in this orifice then that will cause a high-pitched squeal when filling. Throttling the stop valve will reduce this squeal but the proper fix is to clean the orifice.

    Believe me when I state that I understand your quest for quiet. I worked in very noisy environments (often exceeding 85 db) for my entire working life. There is nothing quite as lovely as absolute quiet.


    BTW, my HP Slimline is much quieter than a normal "tower" style computer.
  6. Phil H2

    Phil H2 New Member

    Messages:
    125
    Location:
    Tujunga, CA
    With globe valves, the open area in the valve is proportional to the number of turns the valve is opened. Each turn of the valve increases the valve opening the same amount. Knowing the open area is important in some engineered process systems.

    Gate valves are not designed to be throttled. The flow across the gate can cause erosion of the sealing surfaces. Also, the gate is tapered and held tightly in place when closed. When it is partially open, the gate can have a tendancy to flutter. When a gate valve is cracked open a small amount, it has a tortured flow path between the gate and its seat.

    Many ball valves have a chrome-plated brass ball. On most valves, if the end of the threaded portion (where the nut holding the handle goes) is brass, the ball is brass. Valves with stainless steel balls cost more. Some people like ball valves for throttling, some people do not. It is very easy to bump the handle and change setting. It is difficult to repeat the setting after the valve is closed (with a globe valve the number of turns of the handle can be counted). The movement of a lever handle is not very precise (compare 1/4 turn to multiple turns of a globe valve).
    Last edited: Sep 7, 2007
  7. patrick88

    patrick88 Plumber

    Messages:
    836
    Location:
    Webster Ma.
    rubber washers in older style valves can become worn and will flutter causing some wild noises.

    you can set a 1/4 turn ball valve then remove the handle so knowbody can mess with it.

    "p.s. To get a silent computer, get an Imac. The other manufacturers never discuss their noise level."

    Two Words "Water Cool":D
  8. this answers my basic question, as to why globes are rarely seen but occasionally mentioned as wonderful for certain throttling purposes.

    david
  9. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    The noise in most valve operations comes from the energy lost in the valve. If you throttle the flow you will get more noise. The quietest valve is a full-port vall valve.

    Valves in washing machines, dishwashers, and other devices usually have much smaller orifices than any valve in the supply pipe, and consquently are the source of the noise when those devices are filling.

    The noise in toilet fill is because the valves are small and dissipate all of that energy into the tank where it can be heard around the area.
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