Common Rotary Valve Problems and Ways to Fix Them

Rotary airlock valves are fluid flow control devices that feature rotor blades, which are named so due to the rotary motion. These devices are of great importance in industries where liquid, gas, or steam flow regulation is required. Therefore, the common applications of these valves are found in combustion engines, production engines, chromatography, etc. Although these devices are designed with precision, due to the harsh working environment, they are susceptible to some problems. This post gives insights about common rotary airlock valve problems and ways of fixing common rotary airlock valve problems.

used rotary valves

What Are Common Rotary Valve Problems And Ways To Resolve Them?

Error-free or zero-maintenance rotary airlock valve is a hypothetical concept. There is no rotary valve that is 100% leakage free. Regular usage of these valves leads to operational problems. Let’s discuss all these rotary airlock valve problems followed by their remedies one by one.

  1. Air leakage:

    Air leakage is a common phenomenon in rotary airlock valves. In fact, manufacturers design these valves for around 0.0003 to 0.012-inch leakage clearance. Therefore, an air leak is inevitable in rotary valves. However, if the air leakage surpasses calculated or theoretical air leakage, then it’s a problem. The air leakage can be of two types- clearance leakage that occurs due to an increase in calculated clearances; whereas displacement air leakage is due to change is the location of rotor blades. Thankfully, it is quite easy to fix the rotary valve leakage.

  • How to handle rotary airlock valve leakage?
  • Depending on the type of air leakage, the solution to fix rotary valve leakage varies as follows.

    • For clearance type of air leakage, the installation of flexible seals is an easy and effective solution.
    • However, for displacement type of air leakage, the assembly needs to be dismantled, completely or partially. Displacement of rotor blades or worn-out components causes excessive air leakage. Therefore, to fix the problem the operator needs to disassemble the valve rotor hub and relocate the rotor blades to achieve calculated rotor pocket size. Worn our components are to be replaced with brand new ones.
  1. Jamming:

    Jamming is one of the most challenging rotary valve problems. This occurs due to the trapped material in the valve. It can happen if rotor blades run in the reverse direction, or due to the use of fibrous or chunky material, etc.

  • How to Cure Jamming?
  • To cure jamming, first, it is important to identify the cause. Once the cause is detected accordingly the solutions can be as detailed below.

    • Blade tips beveling is a technique to remove trapped material and avoid it in the future. It prevents material trapping between a hub, housing, blades, or head plates. It prevents shuddering and reverse blade rotation to cure jamming.
    • To avoid material entering the rotor hub, the flexible seal strips can be attached to the blades. These strips allow material to pass over the blades without sticking or trapping inside the clearances.
  1. Noise:

    Noise can be a problem for these rotary airlock valves. If noise is the problem, it may have been caused by material buildup on the blades, fin interaction with the clearances, improper installation, etc.

  • How to Reduce Noise?
  • In order to reduce noise from the rotary valves, the following solutions can be helpful.

    • The valve interior can be coated with nickel or chromium to avoid material buildup. Also, it is important to polish the coating periodically for effective prevention in the material buildup.
  1. Drop-in Material Throughput:

    Drop-in material throughput generally occurs due to excessively leaking rotary airlock valves. However, wrong valve size, material dryness or thickness, are some of the factors that impact here.

  • How to Regularize Material Throughout?
  • In this case, if you have already fixed rotary valve leakage, then you may need::

    • To perform the testing and verifying valve sizes for different materials.
    • Try running the valve at a slow speed to increase the material flow rate.
    • To Increase material temperature, however, this solution is only suitable for limited operations.

Although we have discussed ways of fixing common rotary airlock valve problems, it is important to focus on the valve quality. To ensure quality, durability, and optimum function of rotary airlock valves, you must buy them from trusted suppliers. You can source used and surplus valves if your application is limited. J & M Industrial is one of the well-known suppliers of new and surplus rotary lock valves. The company offers one of the largest selections of used rotary airlock valves from industry-leading brands for your consideration.