Globe Valves

7 Jun

A globe valve is a linear motion valve used to stop, start, and regulate fluid flow. A Z-body globe valve is illustrated in Figure 9. As shown in Figure 9, the globe valve disk can be totally removed from the [...]

TYPES OF VALVES

7 Jun

Due to the various environments, system fluids, and system conditions in which flow must be controlled, a large number of valve designs have been developed. A basic understanding of the differences between the various types of valves, and how these differences affect valve function, will help ensure the proper application of each valve type during [...]

VALVE FUNCTIONS AND BASIC PARTS

7 Jun

Valves are the most common single piece of equipment found in DOE facilities. Although there are many types, shapes, and sizes of valves, they all have the same basic parts.  This chapter will review the common parts and functions of a valve.

Introduction
A valve is a mechanical device that controls the flow of fluid and pressure [...]

POSITIVE DISPLACEMENT PUMPS

7 Jun

Positive displacement pumps operate on a different principle than centrifugal pumps.  Positive displacement pumps physically entrap a quantity of liquid at the suction of the pump and push that quantity out the discharge of the pump.

Introduction
A positive displacement pump is one in which a definite volume of liquid is delivered for each cycle of pump [...]

Preventing Cavitation

7 Jun

If a centrifugal pump is cavitating, several changes in the system design or operation may be necessary to increase the NPSHA  above the NPSHR  and stop the cavitation.   One method for increasing the NPSHA  is to increase the pressure at the suction of the pump.  For example, if a pump is taking suction from an [...]