Ball Valves

How is a ball valve constructed?

In its basic version, the ball valve is made up of three components:

• seal-lined body; 
• ball with through-hole, which acts as a closing element; 
• stem with a separate seal, used to regulate the flow.

Due to their construction, ball valves are used as shut-off valves and are not suitable for flow regulation. The exceptions are those with pneumatic, hydraulic or electric actuation with opening degree control.

What materials are used to manufacture ball valves?

As far as the manufacturing material is concerned, ball valves are primarily made from four types of metal:

• brass 
• stainless steel 
• galvanised steel, 
• aluminium (in special cases).

In addition, there are also plastic pieces, but these are usually designed for a specific application (e.g. a ball valve for a Mauser).

A separate issue would be the type of seal. Inside the body, you will most often find PTFE (Teflon) or RTFE (filler-reinforced Teflon). The valve stem, on the other hand, usually has a seal of NBR rubber, viton or PTFE.

As you may have guessed, the manufacturing material directly translates into the properties and therefore the use cases of the product. This is primarily about industries with strict regulations, such as chemicals or food.

What types of a ball valve are there?

Ball valve can also be distinguished by its design. Their most popular versions include:

• ball valve with screw connection — a basic type of valve of linear construction with two threaded ends; 
• angle ball valve — differs from the traditional version in that it changes the course of the installation by a specific angle; 
• ball valve with filter — as the name suggests, it has an additional filter that retains mechanical impurities of a certain granularity;
• tee ball valve — creates a branching, allowing the medium to be transported via 2 new routes; 
• ball valve with drain (also known as vented ball valve) — thanks to the presence of a drain, air can be easily and quickly removed from the installation; 
• actuator ball valve — a version of the valve which has an actuator (or a place to install the actuator) instead of a manual mechanism;
• flanged ball valve — characterised by having flanges instead of traditional threaded ends; 
• ball valve with tap (spigot) — special ball valves for water (and other media) that have a hose attachment.

In addition to the above division, you will also find on the market ball valves that differ in the type of manual mechanism. Admittedly, this is a less important issue, but it is worth paying attention to.

In this regard, we distinguish:

• butterfly ball valve — has a butterfly mechanism instead of a handgrip; 
• lever ball valve — the most common type of valve closed with a hand lever.

How to choose the right ball valve?

When choosing the right ball valve, pay attention to several important issues:

• manufacturing material and sealing — the intended use of the product largely depends on these (e.g. a brass ball valve for water may not be suitable for transporting chemicals); 
• permissible operating temperature — most valves can operate up to approx. 100 degrees Celsius, but there are also some which can withstand 200 degrees Celsius; 
• maximum working pressure — this parameter depends on several factors (above all the type and size of the valve and the operating temperature). Depending on the product, the maximum working pressure ranges from a dozen to even several hundred bar; 
• type of thread — choose the right one for your installation (most valves have BSP threads, but there are exceptions); 
• thread size — also choose the right one for your installation. You will find a small 1/2-inch ball valve on the market, as well as much larger versions (e.g. a 4-inch ball valve).

How much do ball valves cost?

When it comes to ball valves, the price list depends on a number of factors. The final cost of the product consists of, among other things, the material of manufacture, the type of construction, and the size. Therefore, the price is most often dictated by the needs of the individual customer.