What is a ball valve?

January 7, 2021

By Nationwide SEO Team

A ball valve is a shut-off valve on a pipe that is used to turn gas and/or water on and off. Ball valves use a handle to control the placement of a hollow, perforated sphere (ball) in the mechanism. It’s opened and closed by rotating the ball a quarter turn (90 degrees). You can tell by the handle placement whether the ball valve is opened or closed: When opened, the handle lies flat, in alignment with the flow; when closed, the handle is perpendicular to the flow.

Advantages of ball valves

Ball valves are more effective at forming a tight seal and have more reliability and longevity than gate valves. (A gate valve is a multi-turn valve which operates through a threaded stem, meaning it has to turn multiple times to go from an opened to a closed position; think of a spigot to which you attach your garden hose on the outside of your house.) Here are some benefits of a ball valve:

• Efficiency: Ball valves offer a tight seal with low torque (easy twisting)
• Affordability: They can often be purchased at a considerably lower cost than comparable products for the same job
• Durability: They offer a long service life and, when used under the right conditions, will provide many years of reliable use; ball valves are less prone to damage than other kinds of valves, and the plastic variety aren’t susceptible to corrosion; moreover, their durability means they’re able to maintain and/or regulate extreme volumes and pressures as well as high velocity flows
• Ease of use: Ball valves are relatively quick and easy to install, and plastic ball valves are light and easy to handle; seeing whether a valve is open or shut is also easy
• Versatility: They’re appropriate for a wide range of industrial applications in which it’s necessary to regulate the flow of liquids or gases
• Strength: Ball valves can withstand high pressure, high volume and high temperature
• Simplicity of repair: Repairs can often be made easily without being removed from the pipeline

What are the different types of ball valves?

There are several types of ball valves. Each has a number of models with different features and functional capabilities. Here’s an overview of some of the variations:

Standard port ball valve

The difference between a standard and a full-bore ball valve is directly related to the size of the ball and its bore. Full port bore sizes are the same as the inner diameters of both the valve ports and the pipe used. Standard port bore size is about the same as the next smaller pipe size.

Multiport ball valve

Three- and four-way designs offer flexibility and versatility. Additionally, this type of valve is cost-efficient: One of them can replace two or three conventional straight-line valves, thus eliminating or reducing pipe fitting and expensive automation equipment.

Reduced port ball valve

The flow through this valve is one pipe size smaller than the valve’s pipe size, resulting in the flow area being smaller than the pipe. This type can be used when pressure drops, flow turbulence and material characteristics are not a concern. It also has the advantages of smaller size and lower cost.

Full port ball valve

A full port ball valve has an oversize ball so that the hole in the ball is the same size as the pipeline, resulting in lower friction loss (it does not become narrower on the inside). Flow is unrestricted, with little or no resistance. Most full bore valves are two-way, quarter-turn ball valves.

Cavity-filled ball valve

This type has a unique seat design that eliminates most of the volume between the ball, stem and body — it’s “filled.” This reduces the area for product buildup associated with conventional ball valves, meaning it won’t be as “sticky” as other types.

PVC versus brass ball valves

The choice is yours. PVC is durable and cost-efficient but sometimes a PVC ball valve can be hard to turn or can “stick.” Brass ball valves can withstand higher heat and pressure but can cost up to 4 times more.

Ball Valve Repair Tips

Although ball valves are almost maintenance-free, there are still steps you can take to prevent problems from occurring. Here are some tips for simple valve maintenance:

Clean the area

Sometimes, the easiest way to avoid costly repairs is with a simple, quick cleaning. Depending on the type and location of the valve, you’ll need either a towel to wipe away dust and debris or a wire brush for any “caked on” buildup. At the very least, clean your valves once a year. It’s a quick and easy way to extend the life of the entire system.

Inspect your equipment

Eyeballing your ball valves is another free, simple step in valve maintenance. Simply monitor them for leaks (an easy way to see whether a leak is present is to look for signs of rust, corrosion or mineral buildup). Open and close the valves to make sure they haven’t frozen up. Inspect the pressure and temperature of the medium that passes through them. High-stress valves should be monitored even more regularly than those under less stress.

Lubricate the valves

One of the most inexpensive but overlooked components of valve maintenance is greasing or lubrication. Skipping this step can lead to seizure or, at the very least, decreased performance. Regular lubrication can also help valves seal, extending the life of the valve. The key is to rotate the valve to ensure that the lubricant gets in the valve cavity.

Add protective insulation

You may want to protect your valves from temperature changes, especially if the pipes are outside. If this is the case, add protective insulation.

Tightening the packing nut

If you notice a leaky shut-off valve, your packing nut might be the culprit. The packing nut is the part of the valve that provides a watertight seal around the valve stem. Here’s how you can make a simple fix:

You’ll need a 4-way screwdriver and an adjustable wrench. Use the appropriate-sized wrench to turn the packing nut one-quarter turn to tighten it. This should usually fix the problem. If it doesn’t, you can replace the washer or the packing nut. You’ll need to shut off the water running to this valve, and that means going farther down the line, possibly to the water main for the house. Remove the handle from the stem and then fully loosen the packing nut and remove it. Slide off the washer and put on a new one. Put the packing nut back in place and tighten it, being careful not to tighten it too much; just make it snug and don’t turn it any farther. Then reattach the handle, let the water flow again, and turn on the valve to see whether the leaking has stopped. Tighten further as necessary.

Note: Always operate a ball valve in a fully opened or closed position and do not attempt to regulate flow by partially closing it.

Time and cost of maintenance

Simple home maintenance or resealing as listed above should take only about 15 minutes. However, if there’s an extensive repair or replacement for your ball valve or system, it may take a professional 1 to 3 hours plus material costs, which will depend on the size and quality of the ball valve. The cost for the valve will also depend on the joining method: soldered; press, compression; plastic glue joint, etc.

Remote diagnosis with Anew

If a ball valve shows signs of malfunctioning, it might be symptomatic of a more serious issue, and you might want to consider hiring a professional. Anew offers an easy, efficient and affordable repair service with remote diagnosis.