Evaluating the functionality of compressor valves is an important task which needs to be undertaken to ensure all of the components are both fit for purpose and operationally sound. But what factors need to be gauged, and when should this process be performed?
When to Evaluate Compressor Valves
There are three main periods in a mechanical systems lifetime, which an engineer should always exploit to evaluate a valve’s effectiveness.
1. The design stage of a system is the first of these. Either at conception or during an upgrade of the physical fittings, this is the perfect time to assess the structural merits of a valve and an opportune time to adjudge the overall suitability of the more materialistic qualities offered by the valve, relative to other options available on the market.
2. Secondly, within any mechanical process, there should always be a robust maintenance schedule in place to guarantee that the highest possible standards of safety and efficiency are being achieved. It is during maintenance checks that the reliability and functionality of a chosen valve can be examined to not only improve the integrity of the system, but also compare the expected durable performance of the valve against the actual operational levels that are being achieved, through looking for signs of excessive deterioration.
3. A third and often overlooked opportunity is directly following a maintenance service. This period can be critical to establish that the valve is functioning correctly after re-fitting and can be monitored through checks, ranging from internal flow speeds and pressures to exaggerated or unusual noise detection.
Considerations In Design
As the differing applications of compressor valves have different requirements, there is no golden rule to follow in choosing the most appropriate solution, as each systems requirements must be adjudged on their own merits. There are, however, several key areas which should be focused on when comparing various options.
In addition to the type of valve that you decide upon, the size, shape, strength and speed of the valve in operational context should all be considered in relation to the role that they will fill, along with the actual build of the valve.
Material choice can be an important factor for industrial usage, whereby the components are in contact with either corrosive elements, such as sour gas, or hygiene critical materials in the catering business. The material may also need to be chosen against concerns towards:
- durability of operational fatigue
- extreme working pressures or temperatures
- magnetic properties
Further to this, the actual build and design of compressor valves can have a large bearing on its suitability.
Structural Criteria In Valve Appraisal
The physical design of a valve section within a system can have more options than simply the type of valve that is used. Multi-port valves offer additional paths in the flow stream than the regular input/output trunk from a valve, and another similar option to this is the use of linear valves which are used to reduce extreme pressure that can occur against a single valve.
The valve seat, or type of connection to the pipe, may also be a key consideration as this offers variables in the ease of maintenance, the level of disruption caused to flow stream and above all else, needs to be adequate in withstanding fatigue through exposure to constant forces.
With variable viscosities of flow mass used in differing applications, this also raises the question of the required effectiveness of the seal used within the valve. Not only does the seal need to be specific to the pneumatic or hydraulic nature of the transported flow-stream, but pressure and movement can also play deciding factors towards the final choice, as can the level of allowed leakage in the off position, because not all seals need to be hermetic.
The Essentials Of Valve Maintenance
The frequency that scheduled maintenance services are carried out is dependent upon both the level of importance and usage levels that the valve has within the system, compared to the expected period of time that the part will function at optimal levels. The manufacturers advice should be used as a reference point when planning a maintenance routine to implement.
The maintenance routines used in evaluating valve integrity can be divided into two parts: inspection and testing.
Inspection
The physical inspection of compressor valves is something which normally only occurs at times of response maintenance when a problem is detected and needs to be resolved, such as repairing or replacing a deteriorated part to restore the systems performance levels. This is due to the need to shut down the operation whilst the work is carried out, which not only has a financial bearing but can also cause further problems elsewhere in the system from the interruption to the regular procedure. A common method of circumventing this is to run the process through a secondary route, that allows only a small section of the system to be taken out of action.
Live Testing
In-line evaluations and live testing of equipment is, therefore, the preferred method of monitoring and evaluating a components current capabilities.
With advanced monitoring equipment now available to detect the system’s performance with a high degree of accuracy, open loop bump testing has become a familiar and trusted method within many industries. This process involves a specific control valve being targeted by trimming the control at regular intervals, and then comparing this against data collected from recording the effect it has on the performance of the system. This can verify and be used to further calibrate settings, which will improve performance and reduce the amount of undue stress that can aid component deterioration.
During all maintenance work on compressor vavles, whether they’re scheduled or not, it is always considered good practice to replace the smaller, peripheral components of seals and valves each and every time they’re dismantled for inspection. It should also be noted that this operation should only be carried out by fully trained technicians. This will ensure that the parts are calibrated correctly and to their optimal levels of efficiency, as the knock-on effect of improper installation and human error will likely cause a huge mechanical and financial cost to the business.