Plug Valve: What is a plug valve?

If you are in the valve world at all, you know that the plug valve oftentimes gets a bad rap. There are different reasons for this. One being that the maintenance for these valves is greater than that of other valves. They need to be lubricated while out in the field and more times than not, this is overlooked.

Secondly, due to the corrosiveness and high temperatures of the substances flowing through the plug valves, they tend to wear much quicker than that of some other valves. This means they require patching and maintenance on a regular basis.

Lastly, the plug valve is not the valve of choice when it comes to throttling. You will want a v port, butterfly or ball valve in those types of applications.

On a good note, the plug valve does not clog. And one of the most common uses for a plug valve would be in our homes or businesses where we utilize gas services. The brass, 2 port valve, which is used in gas lines, is conically shaped and its structure bares a handle. When the handle is turned to 90 degrees from the inlet and outlet ports of the valve, the valve flow is shut off. For the gas to flow though the pipes, the handle and plug would need to line up with the inlet and outlet ports of the valve body.

A straightforward description of a plug valve is best described as a rotational valve with a tapered disk resembling that of a plug.This plug or disk sits “long ways” in the valve and has a passageway bored through the center in order to accommodate passing air or fluids. This type of control for corrosive or high temperature air/liquids is economical and simple. With a 2 port valve there are two positions, open and shut. There are also multi-port valves available in the plug valve for different more complex type applications. In applications where there are more than 2 ports, you may have a need for a soft rubber overlay for a sure-tight shut off.Different types of seals are based upon gaskets. Some plug valves close against the gasket and some close directly on the seat.

Many oil field service companies, vacuuming devices and applications which are dealing with glassware stopcocks which create glass products, still utilize plug valves. It does indeed seem to be a dying breed of valves, but with the right material, the proper gasket/seat in a particular application, you may see that a plug valve can be successful for you…especially when expenses plays a factor in your decision.

To assist you better with your valve decision, make sure you contact your Valtorc sales specialist today. They can better educate you on what’s best for you and your application to obtain the maximum results of success.