Isolation Valve FAQs
Isolation Valve FAQs
What are the different kinds of isolation valves?
- Knife gate valves - control the flow of fluids using a gate with a sharp edge that slides across the valve seat. When the valve is open, the gate retracts to allow fluid to pass through. When the valve is closed, the gate is across the valve seat to cut off flow. Knife gates are ideal for handling fibrous fluids, such as in slurry management systems.
- Eccentric plug valves - a cylindrical valve body with a rotatable plug inside, the plug is offset from the centerline of the valve body, creating a straight-through passage when open and a seal against the valve seat when closed. Eccentric plug valves are designed for modulating the flow of various fluids, air and viscous media.
- Butterfly valves - use a disc-shaped element on a rotating shaft (central or off-set) that turns and opens to allow flow in one direction, turning back and shutting to stop flow in the opposite direction. Butterfly valves are best suited for clean water and oil-free airflow control.
- Penstock valves - use a gate that slides up and down between the valve body guides to stop and start the flow of liquid. Penstocks are commonly used in waterways, land drainage, hydropower and flood control applications, as well as being used in water, wastewater and sewage treatment plants.
Where are isolation valves used?
Isolation valves are needed for any situations where flow needs stopping completely:
- Isolating part of a system for maintenance and repairs
- Emergency shutdowns
- Flow control
How do I select an isolation valve?
Selecting the optimal isolation valve model for your application will require consideration to:
- The media being handled - characteristics of the medium passing through the valve - such as whether it is a gas or liquid, if it contains solid, the viscosity of the medium - will determine which model of isolation valve you require to ensure effective pipeline isolation.
- Conditions of the application - the temperature, required flow rate and pressures that are reached during operation will decide the size and material composition of the valve to ensure it operated safely and reliably.
- Actuation method - applications that require rapid valve operation for emergency situations, or that have high pressure ratings, will require suitable control methods. Other factors include whether remote operation is needed to prevent operators from entering into hazardous areas (such as below ground or confined spaces).
Contact T-T Flow to discuss your valve requirements today and our team can advise you on the best equipment for your application.
What is a penstock valve?
Penstock valves are also known as sluice valves and use a sliding door that opens and closes to allow or inhibit the flow of water or sewerage. Penstocks can either be manually operated or by an automatic actuator such as a gearbox, with T-T Flow's model offering bi-directional sealing and stainless steel construction for versatility and durability.