Gate Valves by John Valves
Ideal for services requiring flow or no flow, the gate valve should either be fully closed or fully open. Our gate valves commonly feature in industrial piping where flow isolation is essential in comparison to flow regulation. When a gate valve is fully open, flow is free without any resistance, allowing for minimal pressure drop.
The gate valve features seating that is perpendicular to the line of flow. For this reason, it’s an impractical valve for throttling service and frequent operation.
We locally manufacture and supply a wide range of gate valve options, including:
- Cast steel gate valve
- Forged steel gate valve
- Cast iron gate valve
- SG iron gate valve
- Bronze gate valve
- Flanged gate valve
- Threaded gate valve
- Non rising spindle gate valve
- Rising spindle gate valve
- Rolled grooved end gate valve
Screwed End Bronze Gate Valves
Our screwed end bronze gate valves, the John 59 and 59M have an inside screw non-rising stem. This makes them suitable for installations both above ground and underground. All sizes of these valves are dezincification resistant. As this valve should be used in the fully open or closed position, it is not recommended for throttling.
The John 59 and 59M valves are found throughout applications in mechanical services, domestic water systems, fire protection, hospital equipment & general industrial services within the pressure limitations.
Flanged End Bronze Gate Valves
Our flanged end bronze gate valves include the John 60 and 60M which have a non-rising stem along with a screwed bonnet design. These valves are ideal for all mechanical services, fire services and plumbing installations as well as industrial and general water supply.
SG Cast Iron Gate Valves
The John 600F inside screw and 601F OS&Y gate valves are manufactured in spheroidal graphite iron with bronze seats and wedge rings and stainless steel spindle. They are mainly found in water applications but are also suitable for general use on services such as oil, gas and many other fluids.
Frequently Asked Questions About Gate Valves
Got questions? Below are some of the questions we get asked often about gate valves.
In cases where minimum pressure loss and a free bore is needed, a gate valve is useful.
The gate valve works by inserting a wedge into the path of the flowing fluid or removing it.
Rotating the hand wheel in a clockwise direction moves the wedge down, towards the seat at the lower end of the valve. This process closes the valve. To open the valve, the hand wheel needs rotating in a counterclockwise direction. This moves the wedge upwards, allowing the fluid to flow through. In a fully open position, there is no resistance and, as a result, minimal pressure drop.
The main difference between these two valves lie in their inner elements and flow characteristics. The globe valve offers good throttling ability, whereas the gate valve is best operated in a fully open or closed position.
Another key difference between these valves is the direction in which they can be installed. A globe valve can be installed in a single direction, whereas a gate valve can be installed in various directions.