5 Killer Quora Answers on شركات عزل الخزانات بمكة

Posted by Rosalee on January 2nd, 2021

Pressure relief butterfly valves are flow controlling devices which isolate or regulate the flow of any fluid. Its closing mechanism is a rotating disk, unlike the ball valve. With its expanding usage throughout different industries, butterfly valve castings are very high in demand, globally. So, let's take a quick look at the basics of these valves to understand their relevance.

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How does it operate?

The basic principle of operation is identical to that of a ball valve, which allows for a quick shut off of flow. But usually people are more biased towards the former because of their comparatively lower cost than the latter. In addition, butterfly valves are lighter in weight, hence requiring much less support. A butterfly valve's basic functioning design is:

The butterfly valve belongs to the group of quarter-turn valves. While operating, the valve completely opens or closes with the rotation of a quarter turn of the disc. The "butterfly" comprises nothing but a disc made of metal, which is placed on a rod. The disc is twisted at the time the when the valve remains closed and this ends up blocking out the passageway, whereas, when completely open, the disc on the valve gets a quarter turn rotation, to allow the fluid flow in an unhindered manner. The valve can be opened in a gradual increasing method, to enable throttle of the flow.

Different Kinds of Butterfly Valves

There are different kinds of butterfly valves available to suit different pressures and usages. The most common kinds are-

Usage of Butterfly Valves in Industries

Due to its low cost, high functioning and simplicity of installation, butterfly valves have been replacing ball valves in their several usages (like the petroleum industry). But it is important to make sure that the valves used in these industries are manufactured according to the CGMP (Current Good Manufacturing Practice) guidelines. In different industries, butterfly valve castings are preferred and appreciated alike, by virtue of their efficiency and simplistic design.

Troubleshooting a pneumatic system has been considered an art, a science, or just hit-or-miss luck. In the minds of maintenance personnel, production managers, and plant managers, the word troubleshooting conjures up images of hours of downtime and lost production.

However, when reduced to its basic elements, troubleshooting a pneumatic system is a step-by-step procedure. Using this process can speed up the ability to determine what the problem is, the probable cause of the malfunction or failure, and a solution.

Every pneumatic circuit has a logical sequence of operation that can involve timing logic, pressure sensing, position sensing, and speed regulation. Troubleshooting is initiated when the circuit does not operate properly.

Certain general diagnostic and testing steps can be applied to any troubleshooting problem, whether the problem occurred at startup of a new system or at a breakdown of an existing system.

Think safety firstSafety should always be a prime concern of maintenance personal. Compressed air is a volatile element in a pneumatic circuit. Air receiver tanks have exploded, causing severe injury to personnel and damage to property. It is imperative to relieve pressure in a receiver tank prior to making any repairs.

Air is also highly compressible, which is another reason to be cautious in the approach to troubleshooting a pneumatic system. When working with overhead loads that are supported by cylinders, but not mechanically locked into position, block the load before servicing the system to prevent falling or drifting.

Many pneumatic systems are controlled by electrical or electronic devices. Before attempting service or repair on these components, be sure the electrical power supply has been turned off.

Pneumatic directional control valves that use electrical solenoids to operate the valve spool are often equipped with manual overrides (Fig. 1) that can be used during troubleshooting to operate the system.

Pneumatic lockout valves (Fig. 2) are excellent safety devices that, when used properly on pneumatic systems, can prevent accidental operation. Ensuring a safe condition should always be the first step in troubleshooting pneumatic systems.

Ask the three WsWhen a breakdown in the system occurs, the pressures of downtime loom large in the minds of all concerned. Before beginning repair of a system, stop and ask these three questions:

What is or is not occurring in the system's operation?

When did the problem begin? Was it a sudden failure or a gradual failure?

Where in the machine cycle does the problem occur? Was it at startup or after the system has been operating for a while?

What is or is not occurring in the system can often be answered by the system operator. Answers to questions such as slow actuator speed or inability of the actuator to move could lead to looking for a low flow rate or low pressure.

Asking, "When did the problem begin?' can often lead to troubleshooting steps looking for worn components or leaks. Sudden malfunctions can point to breaks and possible mechanical problems, ruptures in lines, or other catastrophic failures. By determining the when, the problem search can be narrowed in its scope.

Asking, "Where in the machine cycle does the problem occur?" can reveal a reoccurring condition.

If good maintenance records have been kept, reoccurring problems should have been recorded. This information makes the troubleshooting process much easier.

A maintenance person who stops and asks the three Ws can reduce downtime by not having to guess at what is wrong. However, if these questions do not yield a satisfactory diagnosis the maintenance person must begin the mechanics of troubleshooting by visually inspecting the machine.

Make a visual inspectionWalking around the machine will often uncover problems such as worn or burst hoses, loose components, and broken components. This is the time to become familiar with the components contained in the pneumatic system.

If unfamiliar with the components, or if unfamiliar with the machine operation, ask as many pertinent questions about the system as possible. Before trying to operate the system or attempt repairs, understand the interrelations of all the components and the sub-systems found on the machine.

Read the schematicsEvery pneumatic system should have two forms of documentation that will assist in troubleshooting. One document is a schematic drawing of the pneumatic circuit (Fig. 3). The schematic is a road map. It not only explains the operating function of the components but also is a valuable diagnostic tool.

The schematic contains useful information about pressure test point locations; pressure settings of regulators and other pressure valves; flow rates within the system; cylinder stroke lengths, and air motor speeds as well as a bill of materials for the system. This type of information can aid in determining if the system is operating within its design parameters.

Along with schematics supplied by the manufacturer, another set of documents, the service/maintenance manual and its service bulletin updates, may be available to assist in the diagnosis and repair of the machine. These may contain information about the problem that has occurred.

Operate the machineAfter becoming familiar with the components and operation of the pneumatic system, start the machine and operate it to get a first-hand view of the malfunction. See if the malfunction that has been reported occurs again. While operating the machine, perform a visual inspection.

Some questions to ask during the inspection:

Is there any excessive air leakage?

Are system pressures at the levels specified on the schematic or in the maintenance manual?

If there are manual controls for the machine, do they feel stiff or loose in their operation?

Are components that move, moving smoothly or erratically?

By operating the machine, any abnormalities may become obvious, shortening troubleshooting time.

Recheck all servicesBefore attempting repair on the machine after it has been operated, once again check to see if power supplied to the machine has been turned off. Check to see if any stored pressure remains in the system, because this stored pressure can cause premature actuation of the system's actuators and cause injury to personnel and damage to the machine.

Isolate subsystemsA malfunction in one part of the machine can be caused by a malfunction in a different subsystem on the machine. Isolating the subsystems, can help focus on one system at a time. Narrowing the diagnostic area by isolation of subsystems requires extra precaution while operating the machine.

Any lines that have been disconnected and any ports that have been شركة عزل خزانات بمكة opened should be plugged properly to prevent unnecessary air leakage and the entrance of contaminants.

While operating the machine, a close watch should be kept on the pressures within the system, so maximum allowable pressures are not exceeded. Caution and safety are the two keys to this diagnostic step.

Make a listDuring the previous step, the immediate problem may be quite obvious. However, in troubleshooting, the obvious may not be the root cause.

As an example, the obvious problem may be slow actuator speed but the root cause of the problem could be insufficient lubrication, no lubrication due to a faulty lubricator (Fig. 4), or bad seals within the directional control valve that controls the actuator.

After making a list of possible causes, check those items on the list and eliminate them without going back over ground previously covered. This list will also reduce the time required for troubleshooting and can eliminate the parts exchanging