A gate valve for a property usually has to be closed if plumbing repairs or maintenance are needed inside the building. In some instances the valve may not close completely. This happens more frequently if the main control valve is a gate type valve. In many cases a gate valve repair may be needed. But many times other temporary remedies are available.
A gate valve not closing completely is typically due to sediment. As pictured, sediment can build up inside the body of the valve over time. This sediment becomes lodged between the gate that lowers, and the inside of the valve body itself. Ball type valves do not suffer from this problem, as they operate on a different principal than a gate. The gate inside raises and lowers inside of the valve body. This is as opposed to a ball valve, where the ball rotates smoothly inside the valve body..
The typical reaction when a gate valve will not close fully is to exert addition force on the handle. Using force to close a valve is absolutely the wrong response. Brute force can cause permanent damage to the valve. Frequently the valve breaks closed, and this results in a loss of water supply to the building. Sediment or mineral deposits preventing the gate valve from closing fully does frequently happen. There is howver a more sensible first step to take than brute force.
The first step if a gate valve will not close completely
If sediment or mineral deposits are preventing a gate from closing completely, an attempt should be made to flush out the inside of the valve. The proper way to do this is to open a faucet on a sink inside the house. This is done so there is a flow of water. Then gently and repeatedly open and close the valve.
Sometimes the handle of the valve will not turn freely. If that is the case, loosen the packing nut just above the valve body. The packing nut is located around the lower part of the stem of the valve. Loosening it just one turn should be fine, just remember to tighten it back up when you are done. Every time you lower the gate some sediment will break free. This loose sediment will be flushed away by the flow of water. There is absolutely no harm or danger in how many times you do this. Just remember again to not use excessive force. Patience in plumbing is always a virtue.
Routinely opening and closing a gate valve helps it to last longer. If a valve is left frozen in place for long periods of time, it can become frozen. This valve maintenance is called “exercising the valve”. Experienced building managers make this chore a part of their standard maintenance duties.
What if the valve stops almost all of the water flow?
Sometimes a little water will continue to flow after a gate valve is closed as fully as possible. In some cases the plumbing repairs inside the property can be performed with a little bit of water flowing through the system. But there is an other option as well. If there is a slight flow of water the easiest solution is to “jump the valve”.
Jumping a valve simply means to leave the defective valve in place, and simply install a brand new valve after it. If legal for your area, and for your type of water service line, the preferred valve to use is a ball type valve. A full port ball valve allows for full flow of water. Ball vaklves are also typically rated higher than most gate valves. They are also longer lasting, and is not prone to break.
If you choose to install a second main control valve, it is a good idea to remove the handle on the original valve or label it. This will act as a reminder so it is not used in the future. The last thing you would want to do is to use an old defective valve in the future and have it break in the closed position.
Gate valve repair: When a valve breaks in closed position
In most cases if a gate valves breaks in the closed position, gate valve repair work has to be done. Sometimes a curb valve will be located in the sidewalk area. This would enable you to close the curb valve and the water by using a curb box key. A curb box key is a specialty water main tool, and come sin a variety of styles. Once the water is closed, you could then remove the broken valve with little trouble. If there is very little room to work inside the basement where the valve is located, and there is no curb valve, the roadway may have to be opened in order to close the tap connection itself. Opening the roadway can be fairly costly and will involve securing DOT permits.
Changing out a main control valve under pressure can be a very tricky proposition and sometimes dangerous. Removing a valve under water pressure can sometimes be done by highly skilled plumbers, but never when live electric services are nearby. Obviously, when a gate valve repair is needed, there are many nuances to getting the job done correctly. One should never risk an injury or property damage just to save a few dollars.
Sharing a “trick of the trade”
If a gate breaks in the closed position there is a way to raise it back up to restore water service. First drill a small hole near the bottom of the valve body, in line with the gate. As if the valve body were a clock, drill the hole at about 5 0’clock, or 7 0’clock . Do NOT drill the hole at bottom dead center. Then simply use a nail or some other sharp object to push in and force up the gate of the valve. Water will leak out while this is being done but it will be a manageable amount.
After the valve gate is pushed up simply insert a like-sized and self-tapping sheet metal screw into the hole to stop the water. Please note that while this will restore the water supply to the building it is a temporary gate valve repair. The gate valve will still have to be replaced to make a permanent repair and have a trustworthy valve to close the water in the future.
As in most cases it is strongly suggested that a Licensed Master Plumber be contacted when a plumbing repair is required.