How To Close A Water Shut Off Valve & Choosing The Correct Valve To Close

Opinion & Expertise
October 12, 2010

by David Balkan

Water Main Line

Locating and knowing how to close a water shut off valve for your house water service is useful information. It is also something that requires some knowledge, and some care. Many times this seemingly simple task has resulted in a property owner left with no water service for their premises. In other cases, if you mishandle a water valve, it can result in the need for a major water main repair. Following some of simple instructions below can save you a lot of aggravation, money, or having to call a plumber to do a costly water line repair.

Locating the main control valve

The main control valve for a house is typically located on the inside front wall of the basement, or inside an access pit closest to the public roadway. Sometimes there may be a cabinet with an access door built around the main valve. In NYC most houses and properties now have water meters installed. In that case, there can be up to three two shut offs present. There may be two valves on the street-side of the meter, and one on the house-side of the meter. A typical “meter set” diagram is listed just below. Understanding this is important when you need to close a water shut off valve in an emergency.close a water shut off valve

Which valve should you close?

Whenever there are two or more main valves present, always close the one closest to the inside of the house. This is most important because if the valve is faulty or breaks, then the street-side valve acts as a back-up. This would then allow you to still close the water, and repair the faulty valve.

On the other hand, if the street-side valve is used and breaks, or is faulty, the roadway may have to be opened. Needless to say, any time a water main repair is required, it is a costly affair. Therefore, never operate the street side valve unless there is no other option. That said, it is advisable to exercise all water valves in your home about once a year. If any of them seem balky, never use brute force. That is when finesse, knowledge, or a professional maybe needed.Try not to a water shut off valve closest to the street. If it breaks the roadway may have to opened in order to shut the water and replace it.

How to close the main control valve

main valve Most main valves are now of the ball type variety. They are as a rule the most dependable and easy to operate. Since the mechanism to operate the device is a bored out metal ball only 1/4 of a turn of the handle closes the water to the house. There is usually a directional handle to instruct you on which direction to turn the handle on a ball valve. When a ball type valve is used in NYC, it is required to be “full port” opening, meaning the flow of water is not restricted in any way.

Main control valve
Gate type valve

In the case of a gate valve numerous clock-wise turns will be required to lose it. The number of turns depends on the size of the valve. Extra care must be taken with a gate valve as there is a stem that connects the handle to the gate. The stem of a valve can be broken unless care is taken. Always apply even pressure to turn the handle, never jerk a main control valve or use excessive force.

If the stem snaps the shut off valve becomes non-operational. If the stem snaps with the gate in the closed position a main valve cannot be repaired and water main service will be interrupted. This is another example of why knowing how to close a water shut off valve is important information for any property owner.

The importance of a high quality valve

A typical high quality main valve (shut off valve) costs a water main contractor less then $15.00 and should last for decades. Of course, as with most plumbing parts, that is if it is not abused. Frequently just a visual inspection can determine if one valve is better than another. Some things to look out for are its rating (listed on the valve body), it may have a thicker stem, or a heavier body. Most importantly of all perhaps is the rating which is clearly written on the side of the valve body.

There is no reason to skimp on this vital item to save a couple of dollars. As a side note, ball valves have proven to be much more reliable and trouble free than typical gate valves. Ball valves are also much simpler to operate

water line valveAs mentioned previously, the NYC DEP code requires ball valves to be full-port opening valves, which do not restrict the flow of water into the property. Saving a dollar or two on a ball valve that restricts the flow of water makes no sense when considering which shut off valve to install as the main valve. For more sewer and water line information visit the Balkan Sewer and Water Main Resource Page.

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David Balkan

David Balkan is the CEO of Balkan Sewer And Water Main, the largest and most trusted service in New York City. David is extremely active in various NYC plumber organizations being the Chairman of the Subsurface Committee in the Master Plumbers Council, and Vice President of the Subsurface Plumbers Association. In addition David’s expertise is respected by officials of New York City agencies such as the NYC DEP, NYC DOB, and the NYC DOT. He frequently provides valuable input on a variety of industry related matters.

Dave Balkan

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