Seo Safety Oil & Gas :: Air Shut-Off Safety Devices for Diesel Engines

GE designs and manufactures the Rigsaver® air shut-off safety device for use on both large and small diesel engines. When mounted in the air intake system, the Rigsaver will prohibit airflow from entering the cylinders and positively immobilize the engine, safeguarding personnel, equipment, and the environment. Rigsavers can be manually or automatically controlled, responding to a variety of fault or hazard conditions.

It's not always regulatory but it is your responsibility to protect the environment, your equipment and, most importantly, your people.
Hazard prevention with air shut-off safety devices

Airborne hydrocarbons are dangerous. In the open, they can easily ignite and spread to available fuel sources to produce an uncontrolled inferno. But they can also pose a threat to diesel engines of any size. When mixed with the air supply, these vapors or fumes may be drawn into the air intake system, act as an ungoverned fuel source and cause the engine to accelerate out of control.

Conventional shutdown methods (i.e. shutting off the engine's fuel supply) are often ineffective in preventing diesel engine overspeeding since the ungoverned fuel source is still available through the air intake system. Completely shutting off the air supply, using a device such as the Rigsaver, is the only sure way to prevent engine runaway and the possible dire outcomes: equipment damage, fire, or life-threatening explosion.
Air shut-off valves for air intake systems

Rigsaver is a swing-gate, spring-operated air shut-off valve mounted in the air intake system. It will impede the airflow into the cylinders and positively stop the engine. It can be installed pre- or post-turbo. Rigsaver can be manually or automatically controlled to respond to a variety of fault or hazard conditions.
Worldwide experience with diesel engine shut-off valves

The Rigsaver air shut-off valve has been used worldwide, providing reliable service on and offshore under adverse conditions associated with locations in the Canadian Arctic, the Gulf of Mexico, the North Sea, the deserts of Africa, the Middle East and the Pacific Rim. Our product's quality meets or exceeds the stringent requirements of our broad customer base, which includes leading engine OEMs.
Features of the Rigsaver air shut-off safety device

Features of the Rigsaver air shut-off safety device include:

•     Manual or automatic controls
•     Can be used onshore and offshore
•     Can respond to a variety of fault or hazard conditions
•     Available with 2in (50mm) to 14in (355mm) of unrestricted port
•     Operates safely at ambient and induction air temperatures between +350°F to +400°F (+176°C to +205°C)
•     Meets ISO 9001:2008 requirements

Diesel emergency shut-down valve

The Rigsaver acts as an emergency shut-down valve for diesel engines. It is ideal for a wide range of applications, including:

•     Power generation
•     Bulk fuel loading facilities
•     Mining equipment
•     On/off - highway vehicles
•     Offshore platforms
•     Marine engine rooms
•     Petrochemical plants
•     Stationary equipment

Technical data of the Rigsaver air shut-off safety device

•     Temperature rating: maximum constant +400°F (+205°C); high temperature up to +482°F (+250°C) available upon request
•     Maximum pneumatic tripping pressure: 100 psi
•     Maximum solenoid energize time: 5 seconds
•     Vibration tested to simulate in-service conditions to ensure maximum durability and reliability
•     Manufactured with high-grade materials to protect against corrosion for extreme conditions such as oil and gas offshore
•     Available in bore sizes from 2in to 14in
•     Manufactured in Canada

Certifications

The Rigsaver is ISO 9001:2008 certified and is approved for use in hazardous zoned environments under ATEX Category II, Ex II 3G c T3 (200°C, industrial applications). (Note: This does not apply to electrical components.)


Source : GE OIL & GAS

Installing a Sump pum,Types of Sump Pump, Digging a Sump Pit

Installing a sump pump can be an effective way to keep water from accumulating in the basement. The pump is set in a basin, or sump pit, located at the lowest spot in the basement floor or where water first accumulates. Sump pits, which can be purchased at home centers, are most often made of plastic or fiberglass. As the water level beneath the basement floor rises, it fills the pit, activating the pump and causing the water to be discharged to the outdoors. Once the water level falls, the pump shuts off.

If your basement has occasional water problems, a sump pump can be an inexpensive and relatively easy-to-install aid. But keep in mind that installing a sump pump will not address the source of your water problem. So, before you spend any time and money on pumping water out of the basement, take a few moments to learn about the 8 Common Sources of a Wet Basement.

And if your basement is seriously flooded on a regular basis, a sump pump may not be the best solution. After looking at sources of your water problem, you may want to consider these 3 Approaches to Basement Waterproofing.

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Types of Sump Pumps

There are two types of sump pumps usually installed in houses: submersible pumps are fully concealed in the sum pit, while pedestal pumps are only partially concealed, with the motor resting above the water. Pedestal sump pumps tend to cost a bit less than submersible models, and they are easier to repair and maintain. But submersible pumps are quieter, and therefore a better choice for living areas.

Sump pumps usually come with long cords, allowing you to plug them into a receptacle protected by a ground fault circuit interrupter (GFCI). Do not use an extension cord with a sump pump unless it matches the recommendations of the pump manufacturer.

Plumbers can usually install sump pumps, but a motivated DIYer can also handle the job. If you want to install your own sump pump, plan to spend $300-$500 for materials and the better part of a weekend for the installation.

Digging a Sump Pit

You will need a jackhammer to break through the concrete. Electric jackhammers are usually available at rental stores or in the tool rental department at home stores. They are easy to use and can be plugged into regular household outlets. Be sure to get a flat spade bit to use with the jackhammer.

Set your sump basin upside down on the floor, then draw a circle about 4 to 6 inches outside the perimeter of the basin. Be sure to stay at least 10 inches from the walls to avoid the foundation footing. Use the jackhammer to break through the slab along the line.

With the concrete out of the way, dig the hole to the required depth. You want the top of the basin flush with the top of the floor. Set the basin in the hole and fill the gaps around the perimeter with gravel. Level the gravel 1 inch above the bottom of the floor slab, then fill the remainder of the perimeter gap with concrete. Smooth the surface of the concrete with a trowel and allow to set for at least a day.

Installing the Sump Pump

Once the concrete has cured, set the sump pump in the basin as directed by the manufacturer. Connect the check valve and attach PVC discharge piping. Run the piping up the wall and out through a hole you drill in the rim joist.

Extend the piping to the outside, allowing water to drain away from the foundation. If the grade is not suitably sloped away from the house, you may need to install a drywell outside for the discharge piping to empty into. Do not run discharge into sewer or septic systems unless you are sure this is permitted by local building codes.

Seal around hole in rim joist with caulk. Now plug the sump pump into a GFCI receptacle. Fill the basin with water and test the pump.

From time to time you will need to clean debris out of the basin, and if your pump is not activated very often, periodically test it by pouring some water in the basin.

Submersible Pumps

 A submersible pump is a type of hermetically sealed pump device that operates by pushing, rather than pulling, water during its pumping process. It is able to function in this manner because, like the name suggests, the pump is fully submerged in the liquid to be pumped. This allows the pump to be lowered down into a deep hole for pumping needs without running into problems like pump cavitation, which can damage moving parts by developing vapor bubbles. Submersible pumps are used in a wide variety of industrial and commercial use applications.

Submersible Pump Design

Submersible pumps can feature a single stage or multiple stages. Each stage consists of a motor in a casing, closed with mechanical seals to prevent leakage. The motor is connected to a cable that generates power to run the motor, and the casing extends to some sort of pipe or hose leading to the surface. Submersible pumps can be connected to various types of pipes, flexible hoses or wires, depending on the job and the liquid being pumped.

The submersible pump casing can be composed of different kinds of metals, like chrome or stainless steel, or polymers. The most important aspect of the casing is that it is hermetically sealed. If any liquid were to leak into the casing, the motor could short out easily and pose high repair costs. Some casings are fitted with double mechanical seal construction for more strenuous jobs. The cable powering the motor is usually 50 feet in commercial use applications and can be much longer in larger scale industrial situations, such as oil wells. Many casings are also affixed with a float switch, which automatically activates the motor when the pump is fully submerged.

Submersible pumps come in various strengths, both in energy use and pumping speed. Most submersible pumps are rated as effective for a wide variety of liquids, but more viscous liquids at greater depths pose pressure problems that require stronger pumps for proper function. Additionally, some jobs can feature random bits of solid detritus and debris in the liquid, so it can be important to choose a submersible pump rated capable of handling solids. Generally, a submersible pump capable of handling solids will feature an agitator or a spray hole to mix solid particles into the liquid and make it easier for the machine to pump them out of the ground.

Submersible Pump Function

Many submersible pumps operate under the principle of Electric Submersible Pumping (ESP). This is achieved by lowering flowing pressure, which decreases the pressure at the bottom of the shaft in which the submersible pump sits. The motor of an ESP system is also designed to function under high temperatures (up to 300 degrees Fahrenheit) and high pressures, so it is used in situations where very deep wells are common, such as oil wells. They can be relatively expensive to run because they require special electricity cables, although new developments have seen the introduction of coiled tubing umbilicals to supply energy to the deep motors. Additionally, electric usage is much higher than other submersible pump motors and the pump functions on tight tolerances that don’t allow for solids and sand.

Pneumatic Pressure and Flow Control Valve

Pneumatic valves circulate air throughout a larger pneumatic system by either allowing or inhibiting the flow of pressurized air, whose force is then used to power a device. Because valves can have varying numbers of entryways for air, creating different flow patterns, valves are classified according to the number of ports they possess and the flow-paths they create. Additionally, because they can move air in a variety of ways they can suit a variety of applications. Aside from the commonly used directional control valves, there are valves that are designed to serve more specific purposes, such as pressure regulator, venting-type regulator valves, and needle valves. Pressure and venting-type valves both help control pressure, whereas needle valves help control the flow within a pneumatic system.

Pressure Regulators

A pressure regulator is responsible for preventing pressure fluctuation by controlling pressure as it is coursed through an actuator or another part of a pneumatic system. In order to air pressure within an appropriate pressure range, the pressure should be set low enough so that it can fluctuate between 3 and 5 psi without altering the minimum and maximum pressure system requirements. In certain applications, a pressure regulator valve must ensure that air-pressure output stays at a constant regardless of changes in pressure at earlier points in the system and changes in flow. Other applications require pressure regulators to lower pressure so that air isn’t wasted while still meeting the basic pressure requirements of the device.

Pressure regulators work with sensors to monitor the pressure as it expands as it moves through a pneumatic system. Once the pressure has reached the maximum level of expansion, a sensor is triggered by the high pressure, which in turn signals to the pressure valve to close thus cutting off pressure. As a result of the pressure valves opening and closing in response to pressure levels, pressure is kept at a relatively constant level as it reaches the actuator or other pneumatic device.

Venting Regulators

A venting-type regulator functions in much the same way as a pressure regulator does, but also acts as a small exhaust valve to help maintain a constant pressure balance be allowing some of the pressure to exit. There are two ways the excess pressure can be released: an internal bleeding system or an external bleeding system. In an internal bleeding system a venting regulator simply re-routes the additional pressure. In an external bleeding system a venting regular allows the excess pressure to completely exit the system. However, this kind of venting system is not suggested for use with large-flow systems because large volumes of air cannot be released through a venting-type regulator. Additionally, instead of letting the pressure expand, a venting-type regulator monitors the pressure to ensure it remains at a level below that at which it enters the pneumatic system and passes through the venting-type regulator.

Needle Valves

Needle valves are used to help control flow by resticting the amount of air the allow through. In order to restrict of slow down flow, the valve features an adjustable component positioned so as to prevent an actuator or other device from releasing more air than the system can handle at a given time, thus helping maintain a constant flow rate. The adjustable component resembles a needle, which can be screwed into place to block the actuator. As a result of a tightened needle valve, the flow of air not only decreases but backs up inside the actuator, inhibiting the actuator from generating more pressue because of the increase in resistance. A needle valve can be used to reverse the flow of a system or to maintain a constain flow rate.

Turbine and Volute Centrifugal Pumps

A centrifugal pump depends on a rotating impeller to move water through a piping system. The rotating impeller increases water pressure through the effective transformation of kinetic energy. As water is drawn into the pump, the rotating impeller releases kinetic energy into the water. As the water exits outward through the impeller vanes, the kinetic energy (also called velocity) is transformed into pressure as the water moves toward the periphery. Depending on the location and design of the impeller vanes, the water will attain varying amounts of pressure.

Because centrifugal pumps can be used to perform different functions in a piping system and different water pressure levels may be required, there are two general kinds of pumps that control and maintain water pressure differently. The two typical centrifugal pump categories are turbine pumps and volute pumps.

Turbine Pumps

In a turbine pump, multiple diffusion vanes surround the rotating impeller. As water is released from the center (or eye) of the impeller, it spins outwards as the impeller rotates. Around the impeller’s circumference are various diffusion vanes, passages that gradually widen and open into a circular or spiral casing. The main role of diffusion vanes is to reduce the velocity of water slowly, thus transforming velocity into pressure. Once in the outer casing, the water then circles or spirals around toward the nozzle, where it exits the pump.

Volute Pumps

The primary difference between turbine and volute pumps is the presence or lack of diffusion vanes. In volute pumps there are no diffusion vanes, but rather the outer casing is a spiral. The form of the outer casing reduces water velocity (and eventual pressure) by creating an equal flow of water as it moves around the spiral toward the nozzle. The spiral is sometimes called a volute, hence the name for this particular type of pump.

Centrifugal Pump Components: Impeller Considerations

Within each centrifugal pump category, component traits can vary according to the pump’s desired function. An impeller, typically made of brass, bronze or iron, may either be open or enclosed. An enclosed impeller has a front and back protective shroud, whereas an open impeller does not.

Open impellers are often used in low-power applications and the majority of the impeller weight is supported by the hub. When compared to an enclosed impeller operating at the same speed, an open impeller is more efficient because enclosed impellers suffer from disc friction as a result of the close relation of the rotating impeller shrouds to the fixed casing walls. However, open impellers are more prone to abrasion. Because an enclosed impeller maintains a small relative velocity between itself and the fluid, abrasion is lessened. Additionally, enclosed impellers can handle moderate wear without compromising the general performance of the centrifugal pump.

In addition to open or enclosed specifications, an impeller can be single-suction or double-suction. In a single-suction impeller, fluid enters the impeller from one side. In a double-suction impeller, fluid enters the impeller from two sides. Single-suction impellers can be open or enclosed, but double-suction impellers are always closed. Single-suction impellers are the most common of the two.

Double-suction impellers, on the other hand, are often found in horizontally split case pumps or in the early stage of vertical turbine pump system. Additionally, a double-volute casing may be used to reduce radial bearing loads, which are considerably higher in higher-flow pumps.

In applications where thrust is a considerable concern, impellers can be fashioned with pump-out vanes that help move water from out behind the impeller to improve the stability of flow in high-flow applications. As the impeller rotates, the pump-out vanes push the fluid out, lowering axial thrust on the backside of the impeller and reducing pressure. Pump-out vanes can also be useful in removing abrasive agents.

Electrical Submersible Pumps

Electrical submersible pumps (ESPs), much like vertical turbine pumps in design, are typically used to pump liquid. Essentially, an electric motor drives the pump, and the fluid’s kinetic energy is increased. This energy is then partly converted into pressure, which lifts the fluid through the pump. ESPs are centrifugal pumps with vertical shafts, and as a result depend on basic rotating impellers to pressurize fluid.

Centrifugal Pump Basics

Centrifugal pumps feature rotating impellers, typically made from metal, which contain rotating vanes. These vanes transfer energy from the motor to the fluid they propel. As fluid enters the impeller, it accelerates as the impeller rotates. Eventually, the fluid exits the impeller’s vanes at an increased speed, and the kinetic energy is typically converted into pressure.

In an ESP, mechanical seals are used to prevent fluid from flowing into the motor—the motor is coupled to the pump itself, and the entire unit is submerged in the fluid it pumps. Without mechanical seals protecting the enclosed unit, the motor could short circuit and fail.

In cases where more than one impeller is used, the pump is said to be multistage. Multistage centrifugal pumps may feature multiple impellers located on one shaft, or impellers on separate shafts. The result of connecting impellers in a series is higher pressure; connecting impellers parallel to one another results in increased output. Regardless, the fluid will still garner its energy from the electric motor that drives the impellers.

ESP Applications

ESPs are used in many different applications. Single-stage pumps can be used for basic drainage and pumping, as in many industrial applications, and can also handle slurry pumping. Multistage pumps are more often found in water removal applications, and can be used in water and oil wells. Regardless of the application, double checking manufacturing specifications for a given ESP will help ensure its proper use.

ESPs and Oil Wells

Because ESPs can work with a variety of flow rates and depths, they are well-suited to work inside oil wells. When used accurately, an ESP pump can decrease well pressure at the bottom, enabling the withdrawal of a higher amount of oil than otherwise could be extracted under normal pressure conditions. Pump diameter size ranges from 90 millimeters (mm) to 254 mm, and pumps can be one to 8.7 meters long.

ESPs and Dewatering Gas Wells

Some gas reservoirs can produce a high amount of liquid, but because gas can damage ESPs, care must be taken when using an ESP to remove liquid from a gas well. However, ESP systems can be designed that enable the gas to flow freely up the pump’s casing, while the pump efficiently removes fluid. The gas flow depends largely on casing head pressure—there are typically four methods with which ESPs can be used to dewater gas wells, but depending on the exact well situation all ESP set-ups should be sufficiently researched before a method is employed.

Hydraulic Hoses Application

In many hydraulics systems, inflexible or rigid pipes or tubes are used to transfer energy-generating liquid between different components to form a complete hydraulic circuit. Pipes and tubes can be rigid in order to bridge small amounts of space in a controlled manner. For instance, in a hydraulic circuit contained within a small casing, there is no extra room for piping, so the connections must be rigid and contained within the casing. Some hydraulic circuits have much more liberal space accommodations or even require connection flexibility to facilitate faster replacement or range of motion operations. For example, many construction machines have external, flexible hydraulic hose connections so the tools are free to move. A number of standards exist for hydraulic hose production and use. Standards govern industry connection specifications and hose material, as well as guide installation operations.

Basic Hydraulic Hose Construction

The basic hydraulic hose construction involves three layers. These layers help maintain a consistent and reliable flow of liquid while protecting the overall assembly from breaking down as a result of wear or abrasion.

Inner tube: The inner tube is designed to be compatible with the liquid it carries, allowing both free-flowing elasticity and pressure-resistant stress bearing. This tube is often made from PDFE (Teflon), thermoplastic, or synthetic rubbers.

Reinforcement layer: This layer surrounds the inner tube and is composed of a coiled or braided wire. This set up supports the tubing while protecting against tears.

Outer layer: This layer is made of rigid materials and is designed to protect the innards of the hose.

Types of Hydraulic Hose Construction

Due to the variety of hydraulic hose applications and the range of chemicals and pressures they will be subjected to, there are likewise a number of hydraulic hose constructions.

Reinforced: This type of hosing resembles the basic three-layer construction, but with extra buffers in the reinforcement layer, most often in the form of textile braid, wire braid, or wire helix material around the inner tube.

Coiled: Coiled hoses are semi-rigid hoses designed for expansion and easy storing. Because the hose is coiled, it can stretch in such a way that does not put unnecessary pressure on the hose materials.

Corrugated: Another method of increasing expansion and flexibility in a hose is to introduce corrugation. Corrugation manifests as small threads or folds in the material of the hose, somewhat like an accordion, that allow the hose to expand and compress without damaging the housing.

Articulated: Articulated hoses are hoses built in sections, with rigid shafts connected by flexible joints. The articulation allows hoses to turn corners or swivel around other components.

Multi-element: Hoses that involve multiple elements listed above are termed “multi-element hoses.”

Hydraulic Hose Compatibility: Liquids

There are three main kinds of liquid that will pass through a hydraulic hose. These include:

Petroleum oil

Synthetic oil

Liquid with a high-water content

Most hydraulic hoses are capable of transporting petroleum oil and liquids with high-water contents, but synthetic oils require dedicated hose materials. Compatibility ratings are generally available from the manufacturer or from resource literature.

Hydraulic Hose Compatibility: Temperature

Hydraulic hoses are exposed to two temperature concerns: internal liquid temperature and external working temperature. As a result, hoses are rated for performance in terms of both temperatures, with a maximum and minimum functioning temperature rating. Exceeding these ratings can result in severely reduced working life or even failure, so it is pertinent to use a hose that is properly rated to both the liquid temperature and the environment temperature.

Hydraulic Hose Compatibility: Pressure

Hydraulic hoses are designed to withstand both an external and an internal pressure minimum and maximum. Exceeding either of these ratings can severely curtail hose performance. Pressure ratings or recommendations for a specific type of hose are generally available from the manufacturer.

Application Types

With the above considerations about hose performance, it is also important to understand other application necessities for hydraulic hoses. Because pipes and tubes are generally more rigid, they can handle higher temperature or internal pressure in a given application. However, this increased rigidity makes them much more difficult to use in a moving operation. For instance, a construction digger requires a hydraulic system to operate a digging tool, but the freedom of movement needed to operate the tool can place limitations on hydraulic connections. A hydraulic pipe can allow torque, flexibility and elasticity in tool arm movement that is unavailable with tubes or pipes.

Additionally, some hydraulic systems can benefit from combinations of pipes, tubes and hoses. Large vehicles like airplanes require hydraulics systems to operate wing movements and landing gear, but the complexity of vehicle geometry necessitates variation in the hydraulics system.

A general rule used for hydraulic hose installation is to match the hosing to the machine contour. This means that a hose should follow machine geometry as much as possible. If a hose is hanging off of a tool, it can snag or puncture because of the tool’s wider movement radius. By matching the hose to the tool or machinery, an operator does not have to consider extra obstacles when using the equipment.

Choosing a Hydraulic Hose

Hydraulic hose users have a number of temperature, size and pressure factors to consider when choosing a hose for an application. There is a helpful acronym to track all of these considerations—STAMPED.

Size: The important sizes for a hose are inside diameter (ID), outside diameter (OD), and length.

Temperature: Most hose materials have a working temperature range.

Application: Many hydraulic hose applications involve bending, and thus hoses are rated for minimum radius bend. This rating refers to how much the hose can bend, contracting the flow space within the hose.

Material: Compatibility charts are available for hydraulic hoses, usually from the manufacturer or in third-party reference guides.

Pressure: Hoses are rated for maximum system pressure. It is important that hose application intentions include pressure spikes.

Ends: “Ends” refer to the ends of a hose designed for connection, otherwise known as “couplings.” Permanent couplings are designed for attachment to a pre-determined connection. Field-attachable couplings require a user to use crimpers to seal the coupling to a connection.

Duplication (or Delivery): This guideline refers to long-term thinking about how easily a hose is replaced. A very specific or proprietary hose may be more difficult to replace than a widely available generic version. Some hoses wear out quickly due to the nature of their application, and replacement should be considered before settling on a hose type.

Centrfugal Pumping Principle

Many hydraulic systems employ centrifugal pumps to move fluid through a piping system. These pumps all rely on centrifugal force as the fundamental principle by which they operate. Centrifugal force affects an object or material moving in a circular pattern by causing it to pull away from the central axis or center point of the path along which it travels. This force can be used to regulate the pressure and motion within a pumping unit, and when applied in combination with a number of other centrifugal pumping principles, forms an integral part of hydraulic mechanisms.

Generally, a centrifugal pump is based around a casing filled with fluid, usually water. A special unit within the casing exerts fast rotary motion that causes the water to spin, generating centrifugal force that channels it through a discharge outlet. Discharged water creates a vacuum for atmospheric pressure to force more water out of the casing. It is a continuous process, dependant mostly on continued rotary motion and a constant supply of water. Most centrifugal pumps rely on rotating impellers or vanes to provide rotary motion, though the design and implementation of these systems can vary according to capacity and project requirements.

Basic Centrifugal Pumping Concepts

To better illustrate the essential principles of centrifugal pumping, it may be useful to consider a simplified version of an industrial pumping mechanism. A cylindrical can with a pair of rotary vanes along its interior can be attached to a shaft. This shaft has a pulley unit responsible for agitating the can with rotational movements. Once the can is filled with water, the pulley begins to rotate the shaft at high speed, causing the can to spin. As the water in the can rotates, centrifugal force pushes it out toward the walls of the can where it is pressed against the edges of its container.

Because the water cannot continue moving outward through the walls of the can, it begins to climb upward, eventually overflowing while the water at the center point is drawn downward. The overflowing water moves at the same velocity as it does at the rim, meaning that the kinetic energy it produces can be maintained if the water is caught and more water is supplied to the pump. Therefore, a receiving container is usually employed to catch the spilling water and a surplus tank is attached to the shaft to maintain a continuous supply of liquid. The same centrifugal force effect can be achieved without the pulley mechanism by rotating only the vanes or impellers within the can.

Vane and Impeller Functions

The radial vanes within a water casing cause the water to spin when the casing rotates or when the vanes themselves are rotated, making them crucial components in most centrifugal pumping systems. Likewise, the impeller is an integral pumping unit because it provides the rotational force that moves the vanes. Common types of vane and impeller designs include:

Straight Vane: In this basic configuration, water enters the casing through an inlet on the impeller. The impeller rotates its blades, causing the water to spin and generating centrifugal force that creates pressure along the impeller’s outer diameter. When enough force has been applied, the water pushes outward from the impeller and moves through a discharge channel at one end of the casing.

Curved Vane: This design features both curved vanes and a curved casing. An inlet pipe channels water toward the center, or “eye,” of the impeller unit, where curved vanes begin to push it toward the edge of the casing in a spiral pattern. As the rotary force continues to apply pressure, the water is directed into a discharge channel.

Volute: The volute is a single-plane spiraled curve that recedes from a central point. It is designed to match the shape of the casing surround the impeller in a centrifugal pump¸ and forms a passageway for discharged water. The volute expands at certain intervals, growing wider the further along the water flows.

Common Heat Pumps

Heat pump systems are quite similar to air conditioning systems and can either heat or cool the air passing through it. Because heat pumps merely extract heat from the air and transfer the energy, they can be highly efficient because limited amounts of energy are used in the process. In climates where the air is already a moderate temperature, a heap pump can be a cost-effective alternative to a traditional furnace. However, before deciding if a heat pump or furnace is the best solution for a given space or application, understanding the mechanics behind them is key.

Although there are varying types of heat pumps, they all depend on heat transfer to function. Because heat naturally flows from higher altitudes to lower altitudes, heat transfer effectively reverses this pattern—by extracting heat from air in lower temperature realms and moving it to a higher temperature realm—and uses the extracted heat to warm the air in the given heat pump system.

Air-Source Heat Pumps

An air-source heat pump, also called an air-air heat pump, uses heat transfer to draw exterior air into the heat pump. Once inside the pump, the cooler air is passed through coils with refrigerant, where the refrigerant absorbs heat from the air and generates vapor. Next, the vapor is channeled through a compressor where both the temperature and pressure of the vapor is increased. The refrigerant and the vapor are separated—the refrigerant reforms into liquid and is returned to the coils where it can collect more heat—and the vapor is passed on into an air-duct system, where it is then released into the designated space (such as a home or a factory).

Because the compressor in an air-source heat pump features a reverse valve—which, in this case, uses refrigerant to extract heat from the air—the process can be reversed. Instead of trapping heat, the system can be altered to operate in the opposite direction, so that warm air is removed from the environment and released outside. Essentially, the system functions as a basic air conditioner, removing heat to cool the inside environment.

Ground-Source Heat Pumps

In the same way air-source heat pumps extract heat from the air, ground-course heat pumps extract heat from the ground via underground coils. Refrigerant courses through these coils in order to extract heat from the surrounding ground. The refrigerant can then be re-circulated repeatedly, as in a closed-loop system, or can be returned to its natural source (when water is used instead of refrigerant, a local lake can serve as a source), as in an open-loop system. In other regards, ground-source heat pumps function the same way as air-source heat pumps.

Absorption Heat Pumps

Absorption heat pumps are actually a kind of air-source heat pumps, but they do not depend on electricity to power them. Instead, gas, solar power, or heated water is used as a main power source. Additionally, refrigerant isn’t used at all in the process. To extract heat, an absorption pump absorbs ammonia into water. Next, the water and ammonia mixture is pressurized to induce boiling, and the ammonia is boiled off.

Common Types Of Pneumatic Valves

Pneumatic valves are one of an array of components responsible for controlling the pressure, rate, and amount of air as it moves through a pneumatic system. Pneumatic systems, which depend on the force of compressed air to transmit power, can be found in countless industrial applications, from pneumatic pressure power tools to diesel engines. Based on other components within a given application and the type of pneumatic system used, one of several types of pneumatic valves may be found at the heart of the device. Functional directional control valves, those that control the direction of air flow or inhibit flow all together, are a large class of pneumatic valves that houses multiple variants.

pneumatic valvesFunctional Directional Control Valves

Many functional directional pneumatic control valves are classified based on the number of entry and exit ports they possess, the number of flow paths they create, and the mechanism by which ports are opened and closed.

Two-Way Directional Valve

A two-way directional valve passes air in two directions, through two ports which can be open or closed. If the valve ports are closed no air can flow through the valve. If the ports are open, air may move from the first port through the valve and through the second port or in the opposite direction.

Three-Way Directional Valve

A three-way directional valve has three ports, each of which serves a different purpose. The first port is used to connect the valve to an actuator or another device. The second port is connected to an air-flow. The third port is used as an exhaust exit. When the first and second ports are open and the third is closed, air moves through the valve to the device. When the first and third ports are open and the second port is closed, the actuator can vent exhaust. Three-way valves are often connected to actuators in cylinders, or used in pairs and connected to double-acting cylinders.

Four-Way Directional Valves

A four-way directional valve has four distinct ports, two of which connect to actuators, one that connects to a pressurized air-flow, and one that serves as an exhaust pathway. They are among the most common types of valves found in pneumatic systems because the four distinct paths allow the valve to effectively reverse the motion of a motor or basic cylinder. An additional port is sometimes added to a four-way valve, making it a five-ported four-way valve. A four-way valve with an additional port is often used to provide dual pressure, meaning the valve can apply one of two kinds of pressure and alternate between the two depending on what the application requires. Alternatively, the valve can use the other port as a secondary exhaust port.

Spring Offset

This type of pneumatic valve classification refers to the manner in which air-flow direction is switched. For example, in a two-way directional valve, the valve is either open (air-flow is enabled) or closed (air-flow is prevented). In order for each port to assume an open or close position, an actuator moves a valve spool into position. To release the valve spool and return the pneumatic valve to its previous position, a spring releases the spool. A two-way directional valve that functions in this manner is also called a spring offset valve.

Resting state: Open v. Closed

In two-way directional spring offset valves, there are two positions they can assume when the connected actuator isn’t active: open or closed. In devices where an open resting position is standard, air moves freely through the valve. In a closed resting state, the air-flow is blocked. In three-way valves, one port is always open. In such cases, a closed resting state usually results in blocking the air-flow port, so pressure isn’t moving unless the device is turned on.