Gate Valves Key Terms

Learn the ABCs of gate valves
By Jennifer Ehlenfeldt, Freelance Writer A gate valve can be commonly seen in households as a water main shut off, but in a more complex function the valve is used in many industrial settings. The concept of the gate valve is simple: the valve is turned either to allow flow or to stop it.

Gate valves are often used at shut-off valves, or in more complex double block and bleed systems. Learn a few basic functions and terms associated with gate valves before choosing a valve for your job.

Shut-off valves

A shut-off valve is defined as a valve that works to stop the flow of a liquid or gas. They can be manual or power. A gate valve is a type of shut off valve because it controls the flow by either completely opening and allowing liquid through, or closing to stop the flow.
Try:  Read the definition of shut-off valve at ChemiCool.

Pressure reducing valve

A pressure reducing valve is one that eliminates excessive pressure in a tube or pipe. The valve usually is usually set up to release pressure automatically when it is needed. While the valve works similarly to a shut-off valve or gate valve, it is not the same thing because it is designed to release excess, not stop flow.
Try:  The term pressure reducing valve is more fully explained at Valve World.

Double block and bleed

A double block and bleed is a system used to stop flow and drain the area of the pipe. The block and bleed uses a shut off at two ends with a release valve to allow the drain of liquid from the section.
Try:  GMI Valves explains the double block and bleed concept in its glossary of terms. The glossary also includes many other valve terms that can be helpful in finding the right gate valves.

Stamped capacity

Most valves have a rating based on how much pressure or fluid they can handle at one time. The rating is normally "stamped" on the valve, which gives it the name stamped capacity.
Try:  ControlAndInstrumentaion.com explains the stamped capacity.

Pressure temperature rating

The pressure temperature rating is a similar term to stamped capacity, but with a more advanced configuration. This rating is based on the amount of pressure a valve can handle at any given temperature.
Try:  The Valve Shop defines the pressure temperature rating and explains how it is determined for valves made of different materials.

Actuator

The actuator is the means of opening and closing a valve. The actuator can be pneumatic, electrical or hydraulic. These devices are commonly used when the actual valve can not be reached by hand or is too big to be operated manually.
Try:  The actuator is defined in the GlobalSpec.com glossary.