What is a forged steel gate valve?
A forged steel gate valve is a gate valve that is made through the forging method. This manufacturing method entails heating a steel material until it becomes hot and soft. The hot material is then shaped using mechanical forces to produce the desired shape. Forged steel gate valve manufacturers design these valves for high temperatures and pressure. They are thus suitable for transporting high-pressure fluids due to their high strength. The forging method and steel material make the valve relatively solid compared to other valves and help reduce thermal stress. The valve design includes an actuator which is most commonly a handwheel. Other actuators used in this valve include electric, hydraulic, or pneumatic. The choice of the actuator depends on certain factors, among them an overall budget, the torque needed to operate the valve, and if automation is required. These valves allow flow in either direction of the piping system. Industries that use this valve include power plants, oil, and chemicals.
Figure: Forged steel gate valve.
Components of a forged steel gate valve
Handwheel
Handwheel is where you hold the valve to apply torque to start or stop fluid flow. The handwheel has a mechanism that enables the rotary force applied to move the valve disc up and down to open and close fluid flow, respectively.
Stem
Stem is a threaded shaft. This component connects the handwheel to the valve disc. It is responsible for transmitting the torque applied on the handwheel to the valve disc. Forged steel gate valve manufacturers have two designs of the stem that is the rising stem and the non-rising stem. As the name suggests, the rising stem rises upwards while the valve opens. Due to the stem rising upwards, the valve needs installation with enough space to accommodate the raised stem. It is reliable and helps the operator quickly know when the valve is opening and closing. The non-rising stem version is designed to move the valve disc upwards without the stem rising past the stem nut. The non-rising version of the valve is accompanied by a dial indicator that notifies the user when the valve is closing/opening. It occupies less amount of space relative to the rising stem type.
Disc
The disc is the component responsible for opening and closing the valve. A handwheel powers the disc via the stem. It moves upwards to allow fluid flow and downwards to stop fluid flow.
Body
The valve body is an outer part that houses the valve seat and disc. It is usually thick to enhance its ability to withstand high fluid pressure and temperature. Its strength ensures the valve is safe against impact damage from falling objects. The valve body contains the inlet and outlet ports of the valve. These ports are designed with butt ends or flanges to connect the valve to the pipe.
Valve Seats
Seats are components used to enhance tight seals between the valve disc and the body when the valve closes.
Bonnet
Bonnet is another part of the body mounted on top of the valve body. The bonnet helps to contain fluid pressure and prevent dirt entry into the valve. It makes accessing the valve’s internal components easy for cleaning and repair.
Gland packing
Gland packing is configured around the stem to seal against fluid leakage and entry of dirt into the valve.
Figure: Components of a forged steel gate valve.