Reasons for the breakdown of the compressor valve disc

This situation is usually caused by the actual operating conditions of the compressor, with the gas flow rate not matching the design specifications. A good solution is to have a professional manufacturer design new valves based on the actual operating conditions. It is recommended to contact Holbig Company and use plastic valve discs.

The valve plates of the compressors in our factory have also experienced breaks; the material used is 3Cr13. Given our operating conditions, the compressed gas is relatively clean, so there’s no need to clean or replace the valve plates as often as with methanol. More effort is still needed in terms of the material and manufacturing processes. The springs also need to be replaced regularly. I’m not sure if this is correct

The new small-plate air valves from the Lanzhou Chemical Machinery Research Institute have given good results for us.

For systems that use coal as a raw material, the gas in the low-pressure section of the compressor is quite dirty, with a high content of coal tar; what type of gas valve should be used to achieve good results? Now, valves have to be cleaned every month, which is labor-intensive and results in significant waste.

First, consider the composition of the medium; if it is gas, it is relatively dirty, and sometimes a filter is installed at the inlet using coke as the adsorbent. Otherwise, ordinary ring valves are used, and even Helbig valves require regular cleaning due to their high cost. It is advisable to remove water from the gas regularly, which will yield better results

Dirty media manifests as leakage in valve failures, but frequent breaks in the valve discs and springs certainly can no longer be attributed solely to gas quality issues. We encounter this situation: generally, the intake valve of a compressor is the dirtiest, but its valve plates and springs rarely break. The valves in stage 4 are not dirty, yet valve failures occur far more frequently in this stage, and it is often the valve plates and springs that break (similar to what happens with LZ). The situation improved significantly after the modification of the fourth-stage valve.

Based on the poster’s question, I would like to share a few of my thoughts for discussion: 1. Check whether the compression medium is too dirty or contains impurities; an excessive amount of impurities can certainly lead to the breakdown of the valve disc. 2. Check for liquid slugging, as this condition can also easily cause the valve disc to break. 3. From a design perspective, consider whether the lift of the air valve is too large, as this too can result in the breakdown of the valve disc. 4. Verify that the springs used are appropriate; springs from different stages of the valve system should not be mixed together, as an incorrect choice of spring can also cause the valve disc and springs to break. We mostly use Halberg’s polytetrafluoroethylene valve discs, which have good impact resistance.

We have also encountered this phenomenon. Upon analyzing the reasons, it is mainly a problem with the spring; when the spring force is uneven, that is, when the extension amounts differ, or when the spring breaks due to issues with its heat treatment, it can lead to the breakdown of the valve disc. Replacing the spring as soon as possible and cleaning out the deposits at the spring seat will improve the situation. It is not advisable to use stainless steel springs – 50CrVA is sufficient

If the exhaust temperature does not exceed 135 degrees, PEEK valve discs can be used; if there are many impurities, the fungal-shaped valves from DR work very well

One of the compressors in our plant has a high outlet temperature, which causes the material gas to polymerize; I’m not sure what methods can be used to lower this temperature.

1. Reduce the temperature and pressure of the incoming gas. 2. Lower the temperature of the coolant in the cylinders (while also cleaning it regularly). 3. Decrease the compression ratio for that stage. 4. Improve the air valves. These are the main four methods; obviously, the third one is the most effective, followed by the first. However, these methods are usually not practical or difficult to implement. Therefore, only the second and fourth options are available, but their effectiveness is limited. It is hoped that the goal can be achieved; if not, and if gas polymerization needs to be avoided, then it will probably be necessary to consider carrying out the first option. :lol

What can be resolved easily at present is to check the condition of oil and water inside the cylinder to determine whether this issue is caused by them. Our company also encountered similar problems with the air valves for a while; the first step taken was to improve the quality of oil and water removal as well as the maintenance of the air valves. Things have improved recently, but it has been observed that the valve plates in certain series of valves frequently break. It is suspected that this is due to an excessive amount of oil and water, as well as a small oil-water separator; therefore, we plan to replace it with a larger one, though it’s not clear what the effect will be.

Due to its incompressibility, the liquid exerts force on the cylinder and piston, which can damage the valves； Debris and dust can clog the channels and interfere with the free operation of the valve plates; they can also exert stress on the air valves, leading to damage to the components. Generally, air valves are most prone to damage between 0.5 and 200 hours after startup. As for the reasons for the spring breakage: 1. The service time exceeded the designed lifespan, resulting in normal fatigue fracture ； 2 The spring material and spring force selected do not match the operating conditions ； 3 The spring was not installed correctly during maintenance or assembly, or the spring itself is defective ； 4 Do not install new springs and old springs in the same air valve. The pulsating airflow from the compressor can cause the valve plates to move diagonally as it passes through the valves. The outermost part of the valve plates experiences the highest impact velocity and is subjected to the most collisions, which makes them prone to premature damage.

The impact of corrosion on the lifespan of air valves and springs: 1. On the valve disc, surface corrosion spots directly lead to a decrease in airtightness; severe corrosion reduces the strength of the valve disc, causing it to get damaged； 2 springs: Compared to the valve disc, springs are more susceptible to corrosion. In over 50% of cases, damage to the valve disc occurs because the springs fail first, which leads to an imbalance in the movement of the valve disc and results in excessive local stress that causes damage.

The fracture of valve discs and the quality of these discs are closely related to the compressed medium and the operating pressure. The valve discs used in our factory, which are of domestic origin, often cause problems and need to be replaced; those imported, on the other hand, perform better

If the valve disc breaks frequently, considering switching to PEEK might be a good idea; it should perform better.

How did you make the modifications? We also use four-stage valve discs, with the springs breaking frequently

Prolonged back-and-forth movement will inevitably cause the spring to fail and the valve disc to break