Ball Valves

ball valve

Ball Valves by John Valves

These types of valves consist of a spherical obstruction that is used for stopping and starting the flow of liquid or gas. They require a 90 degree rotation for opening and closing. When fully open, ball valves allow for unrestricted flow. In their fully closed position, they offer drop tight shut-off.

Their long service life and reliable sealing makes ball valves one of the most popular valves, particularly in the oil and gas industry.

We locally manufacture and supply a range of ball valves including:

  • John Fig. 801 One Piece Screwed Stainless Steel Ball Valve
  • John Fig. 802 Two Piece Screwed Stainless Steel Ball Valve
  • John Fig. 803 Three Piece Screwed Stainless Steel Ball Valve
  • John Fig. 804 Two Piece Flanged Stainless Steel Ball Valve
  • John Fig. 805 Two Piece Flanged Fire Safe Carbon Steel Ball Valve

Frequently Asked Questions About Ball Valves

Got questions? Below are some of the questions we get asked often about ball valves.

A ball valve is most commonly used as a shut-off valve.

The ball valve and gate valve are both usually operated in the fully closed or fully open positions.

A ball valve has the ability to open and close quicker than the gate valve as they only require the handle to be operated 90 degrees This may be essential in some installations whereby needing to isolate pipe sections quickly is required.

The ball valve and plug valve have many similarities in terms of how they function and their application. They are both used for providing drop tight shut-offs in different piping systems. They do, however, have a few key differences.

Where we see a spherical disc with a hollow centre in a ball valve, a plug valve consists of a conical disc that has bored passages running through it.

The plug in a plug valve is larger than the ball in a ball valve. This means that the plug valve provides a tighter shut off in comparison. It’s important to note though, that this tighter shut off, as a result of a larger surface area, does translate to increased torque. The downside of increased torque is that it can lead to operational difficulties.