Reciprocating Pumps Pulsation Signature
Reciprocating pumps emit strong pulsation when there is no pulsation countermeasure. Reducing pulsation saves not only pump wear but also piping fatigue life. Reciprocating pumps use a reciprocating piston to displace fluid volume. Inlet flow is controlled by a passive valve, i.e. a springloaded valve that opens when the piston expands the cylinder’s volume (see Figure 1). The discharge valve is closed during the suction stroke. The discharge valve is opened when the piston decreases the cylinder’s volume.The suction valve is closed during this compression stroke. (A) (B) Figure 1. A) The...
read moreEmergency Generators
Reserve power, e.g. emergency diesel generators, are not units intended for continuous operation, but rather systems tasked with vital safety functions. To ensure this system safety function, these systems are tested for a specified period of time at regular time intervals; say, a few hours every two weeks. A common problem for these types of units is that their heaviest components, the motor and the generator, rest on weak skids and frames. Industry-sized generators emit a fair amount of structure-borne noise and can become a potential noise source when located near offices and living...
read morePiping Vibration Physical Mechanisms
The root cause for piping vibration can be one or many of the following: Mechanically-induced vibration Fluctuating Line Pressure (LP) Flow-induced by variations in Kinetic Pressure (KP) Pulsation-driven, i.e. excited by propagating waves in the pipe system Figure 1. Pressure, Line Pressure, Pulsation and %LP. %LP matters for the generation of shock waves from wave steepening, a topic treated elsewhere in this Learn More section. (Click on figure to expand) Mechanically-induced vibration tends to be the largest near a machine or perhaps, externally-induced vibration transmitted e.g. via a...
read moreVibration Isolation
Vibration isolation often is assumed to be a component property, i.e. something exclusively related to the isolating spring component or the resonance frequency of the mass-spring system (see Figure 1). The component property assumption is of importance as it affects how we act and think when dealing with vibration isolation. Believing that vibration isolation simply is an item to purchase can mislead your engineering process as you overlook a number of things that affect the end result. Note – We assume that the reader understands the sdof system shown in Figure 1. If not, read this...
read moreSite Survey
Science buildings often are high-risk projects because: The end customer does not often order a new science building. The building contractor team usually only gets to build a specific kind of science building once. The consultant usually has limited knowledge about what is required for scientific machines to work well and may not have participated in this type of project before. As the usefulness of the science building stands or falls with its performance, our advice is to use a risk based project management philosophy when constructing science buildings. Scientific machines usually have...
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